Test di Medicina 2022 Worked Solution

Full explanation

The term metabolic flexibility is explained in the 3rd sentence as the ability of the muscle to use either carbohydrates or fats, depending on the availability of the energy substrates.

The option that describes the term most closely is option A.

Full explanation

This reading passage uses uncommon historical terms.

But we can infer from the text that there is a heritability for minor vassals.

This inheritance cannot be deprived by lord or count, or bishop.

Option A: The goal is not to deprive great lords; the goal is more inclined towards the benefits of lesser lords.

Option B: This is the most consistent answer.

The edict aimed to reduce the power of the great feudal lords by granting minor vassals (valvassors) the right to inherit their fiefs, thereby making them less dependent on the whims of their superiors.

Option C: Subordinate relationship is not mentioned in the text Option D: The passage is not about preserving the right.

It is extending the rights.

Option E: The Emperor’s responsibilities are not mentioned in the text.

Full explanation

The text is a travel diary because it combines a dated, location-based entry with first-person reflections on the author's personal experiences and the weather while on a cultural pilgrimage.

Other options:

A) Historical novel: While it mentions historical art, the tone is a direct, non-fictional recording of a day's events rather than a plotted narrative with character dialogue and conflict.

B) News report: The language is too poetic and introspective ("almost friendships," "cheered up my rooms") for the objective, factual tone of journalism.

C) Sonnet: A sonnet is a poem with a strict structure (14 lines with a specific rhyme scheme). this is prose.

D) Epic poem: Epic poems (like the Odyssey or Aeneid) are long narrative poems, usually written in verse, focusing on heroic deeds and grand-scale events.

Full explanation

In the Italian political and economic system, DEF stands for Documento di Economia e Finanza (The Economic and Financial Document).

It is the most important document for national economic policy and financial planning.

The DEF is prepared by the government (specifically the Ministry of Economy and Finance) and must be submitted to Parliament for verification.

It outlines the reforms and financial measures the government intends to implement to reach those targets.

Therefore, the correct answer is option A. B, D, and E: These are fictional names or "distractor" terms that use words related to finance and economy but do not correspond to any actual Italian institutional document.

C: While "Financial Balance" is a concept in economics, the document that defines the specific tools for the budget is usually the Legge di Bilancio (Budget Law), which follows the DEF later in the year.

Full explanation

Let the expense on June 2021 = x Expense in June 2022 = x+ 125/100x=x+1.25x=2.25x= 9/4 x Therefore, the ratio between June 2022 and 2021 is 9/4

Full explanation

The route Martina planned has a trattoria exactly halfway.

She starts riding and, after 30 km, she is at ¾ of the distance to the trattoria.

Therefore, the distance to the trattoria would be 30km + 1/3 x 30km = 30km + 10km = 40 km Total length of the route = 2 x 40 km = 80km

Full explanation

Digits from 1 to 8 (inclusive) = 1,2,3,4,5,6,7,8 Digits that have at least two of the given properties?

Since there are 3 properties, we can have 3 different combinations with at least 2 properties. odd digits which are ≥ 6 = 7 odd digits which are ≤ 6 = 1,3,5 Digit which is ≥ 6 and ≤ 6 (This combination is not possible because each properties subtract one from the other).

Therefore, digits that have at least two of the given properties = 5

Full explanation

The pattern begins with the number 3.

If the current number is even, it is divided by 2; if it is odd, 5 is added to it.

The sequence according to this pattern would be: 3, 8, 4, 2, 1, 6, 3, 8, 4, 2, 1, 6, 3, 8, 4, 2, 1, 6, 3, 8 (20th position)

Full explanation

Given facts: In a box, there are spheres and cubes.

Each solid is either red or blue. 60% of the cubes are blue, 20% of the blue solids are cubes.

There are 20 red cubes.

Solution: Since 60% of the cubes are blue, the rest 40% would be red cubes.

Since the number of red cubes is given (20), Total number of cubes = 20+(20 × 6/4 )=20+30=50 Number of blue cubes = 30 Since it is given that 20% of the blue solids are cubes, Number of blue spheres = 30 × 8/2=120

Full explanation

Weak interactions include all types of intermolecular bonding, such as hydrogen bonding, Van der Waals interactions, and hydrophobic interactions.

Among the given options, only the primary structure of proteins is a linear amino acid chain held together by covalent peptide bonds.

Therefore, the primary structure of proteins is not determined by weak interactions.

Analysis of the other options Option B: Antigen-antibody bonding – rely on weak interactions such as hydrogen bonds, Van der Waals force, and hydrophobic interactions.

Option C: Secondary structure of proteins – formed by hydrogen bonds between the functional groups of the amino acid backbone.

Option D: Codon-anticodon pairing – relies on hydrogen bonds between the bases of the nucleotides.

Option E: Passage of H₂O through aquaporins – relies on electrostatic interactions.

Full explanation

Cellular respiration, or the process of breaking down glucose into carbon dioxide and water while releasing energy, is the oxidation process.

Carbohydrates are composed of C, H, and O, and their general formula is CH₂O. Carbohydrates can be called sugars or saccharides.

Plants can synthesize glucose using light energy to fix carbon from carbon dioxide.

Therefore, option B is the incorrect answer among the given options, as explained above.

Full explanation

Among the given options, a characteristic exclusive to eukaryotic cells is the presence of mitochondria because prokaryotes do not have membrane-bound organelles.

Prokaryotes have a plasma membrane, double-stranded DNA in ring form, ribosomes, and machinery for genome replication.

Full explanation

Since it is mentioned that the CFTR protein regulates the movement of chloride and water from inside to outside the cell, without the CFTR protein, excretion from the cell would be reduced or absent, leading to a lack of chloride and water.

Therefore, the correct option is E.

Full explanation

Microfilaments are solid, 7-nm-diameter cytoskeletal fibers composed of two intertwined strands of globular actin (G-actin) monomers, forming filamentous actin (F-actin).

Therefore, the correct answer is option

B) actin.

Tubulin polymerizes into microtubules, which act as hollow "railroad tracks" for cellular transport.

Kinesin is a motor protein that moves toward the plus-end of microtubules.

Dynein is another motor protein that moves toward the minus-end of microtubules.

Myosin is a motor protein that moves along actin filaments important for muscle contraction.

Full explanation

Aneuploidy is the presence of an abnormal number of chromosomes in a cell.

It results from errors during cell division.

During cell division, segregation of chromosomes is carried out by the assembly/disassembly of spindle fibers, which are composed of microtubules.

Therefore, the correct answer would be option

D) microtubules.

Full explanation

Karyotyping is usually performed during metaphase of cell division, when the chromosomes are most condensed and aligned at the equatorial plate.

Therefore, the correct answer is option

C) Metaphase

Full explanation

Progesterone is an important sex hormone that is produced by the corpus luteum in the ovaries after ovulation to prepare the uterus for pregnancy.

Luteinizing hormone (LH) is the primary hormone that stimulates progesterone production in females by promoting the formation of the corpus luteum after ovulation.

Progesterone is also produced by the adrenal glands and, during pregnancy, the placenta takes over production.

It is crucial for endometrial preparation, thickening of cervical mucus, and regulating the menstrual cycle.

Analysis of the given options: Option A: It is produced by the ovary from the first day of the ovarian cycle false.

Only after ovulation in the luteal phase (days 15-28) does the empty follicle transform into the corpus luteum, which then begins pumping out progesterone.

Option B: It is produced by the corpus luteum True.

This is its primary source during a standard menstrual cycle.

Option C: It is produced by the placenta True.

If a woman becomes pregnant, the placenta eventually takes over progesterone production from the corpus luteum.

Option D: Its production is controlled by the luteinizing hormone (LH) In a non-pregnant cycle, the "Luteal" in LH refers to its role in maintaining the corpus luteum and stimulating it to produce progesterone.

(In pregnancy, hCG mimics LH to keep this process going).

Option E: It keeps the uterine musculature relaxed True.

Progesterone is a powerful tocolytic (muscle relaxant).

It prevents the uterus from contracting prematurely, which is essential for allowing an embryo to implant and grow safely.

Full explanation

We are crossing an individual with dominant traits (AB) and an individual with recessive traits (ab).

The ab parent must be aabb (homozygous recessive) to show that phenotype.

They can only contribute ab gametes.

The AB parent's genotype is what we need to find.

If the genes were on different chromosomes (independent assortment), a dihybrid cross (AaBb×aabb) would typically result in a 1:1:1:1 ratio of four phenotypes: AB, ab, Ab, and aB. Since we only see two phenotypes (Ab and aB), the genes are clearly not assorting independently; they are linked on the same chromosome.

In this specific problem, the offspring are 50% Ab and 50% aB. This means Ab are on one chromosome, and aB are on the other.

Therefore, the correct answer is option

D) AaBb for linked traits

Full explanation

Analysis of the given options Option A: Two sick parents have a healthy child If the parents have a homozygous recessive genotype, all the offspring will inherit one recessive allele from each parent, resulting in a homozygous recessive genotype and disease expression.

Therefore, it is impossible to have a healthy child from two sick parents.

Option B: Two healthy parents have a sick child This is a possible scenario if both parents are heterozygous and the child receives the disease allele from each parent.

Option C: One sick parent and one healthy parent have a healthy child This is a possible scenario if the healthy parent passes on their healthy allele to the offspring.

Option D: Two healthy parents have a healthy child This is a possible case scenario for parents with either a normal homozygous or a heterozygous genotype.

Option E: One healthy parent and one sick parent have a sick child This is a possible scenario if the healthy parent is heterozygous and passes on the mutated allele to the offspring.

Full explanation

If a single nitrogenous base is changed in the coding sequence of a eukaryotic gene (a substitution), it can have the following effects.

If the new codon codes for the same amino acid, the new protein will be identical to the previous/original one.

If the new codon codes for a stop codon, translation stops, resulting in a shorter amino acid chain/protein.

If substitution happens at the stop codon and the new codon does not code for a stop signal, transcription continues, resulting in a longer chain of protein.

If the new codon codes for another amino acid, it would lead to a protein with one substituted amino acid.

However, it is not possible to produce a protein with multiple substituted amino acids.

Therefore, the correct option would be option A)

Full explanation

Given nucleotide triplet is AGU. Since it contains uracil, the nucleic acid is RNA. To be paired with another RNA (UCA), the condition where RNA pairs with RNA occurs during the translation or protein synthesis phase.

Also, viral RNA replication is the synthesis of RNA using RNA as the template, as the name implies.

Therefore, AGU can be paired with UCA also in this case.

Transcription is the synthesis of RNA using a DNA template.

So, this is not RNA-RNA binding.

Viral DNA replication is the synthesis of DNA using DNA, so this is also not RNA-RNA binding.

Therefore, the correct answer is Option

D) processes 2 and 4

Full explanation

During PCR, there are 3 main phases: Denaturation (94-98 °C to separate DNA strands) Annealing (Primer binding: primer is not synthesized.

It is provided) Elongation (for polymerase activity: need thermostable Taq DNA polymerase) During the denaturation phase, we use high temperatures (typically around 95°C) to break the hydrogen bonds between the two strands of the DNA double helix.

In a living cell, heating your DNA to near-boiling temperatures would be lethal.

Instead, the cell uses a specific enzyme to achieve the same result at physiological temperatures.

This enzyme is called helicase.

Therefore, the correct option is option

E) Helicase.

Full explanation

Analysis of the given options We have to choose an incorrect option Option A: The change of an amino acid resulting from the point mutation leads, in the case of oxygen deficiency, to hydrophobic interactions in the β-globin molecules Correct.

This explains sickle-cell anemia.

Option B: The HbS allele differs from the wild-type allele by a point mutation affecting a single nucleotide Correct.

The HbS allele is a sickled cell allele, which causes a substitution of glutamic acid with valine at position 6 of the beta-globin chain.

Option C: The HbS allele, since it causes a lethal pathological condition in homozygotes, has a low frequency in all human populations The HBS allele, though lethal, is common in certain populations and confers a survival advantage in malaria-endemic regions because sickled cells are less hospitable to the malaria parasite.

Therefore, this is incorrect.

Option D: Heterozygous individuals in populations subject to malaria have a higher probability of survival Correct.

Their red blood cells are less hospitable to the Plasmodium parasite that causes malaria, and infected cells are cleared more quickly by the spleen.

Option E: The advantage of heterozygotes in malarial regions keeps the frequency of the HbS allele relatively high (15–20%) Correct.

Since heterozygotes survive malaria better than normal homozygotes, the environment selects for the HbS allele to stay in the population at surprisingly high levels.

Full explanation

Plasma cells (activated B-lymphocytes) are the specialized factories solely responsible for pumping out antibodies.

Neutrophil granulocytes: They degranulate and produce potent antimicrobial proteins and enzymes to kill bacteria and fungi.

T-helper lymphocytes: They don't kill or make antibodies themselves; instead, they release chemical signals (cytokines) to tell B-cells to become plasma cells and tell T-cells to attack.

Cytotoxic T cells: They perform direct cell killing by producing perforins and granzymes.

Basophil granulocytes: They produce and release histamine and heparin to trigger inflammation.

Therefore, the correct answer is option

D) plasma cells

Full explanation

Transitional epithelium can be found on the bladder.

(also on the ureter and urethra).

It is a specialized type of tissue designed specifically for organs that need to stretch and recoil significantly.

The uterus is lined with simple columnar epithelium.

The esophagus and pharynx are lined with non-keratinized stratified squamous epithelium.

This tissue is tough and multi-layered to protect against the friction of swallowing food.

The trachea is lined with ciliated columnar epithelium (often called "respiratory epithelium").

It features tiny hairs (cilia) and goblet cells to trap and move mucus.

Full explanation

Striated muscles include skeletal muscles and cardiac muscles.

Smooth muscles are non-straited.

Among the given options, only option

A) contractile myocardium is composed of striated cardiac muscle cells.

The rest of the muscles are smooth muscle cells (non-straited).

Therefore, the correct option is option A.

Full explanation

In the absence of oxygen, many cells use fermentation to produce ATP by substrate-level phosphorylation.

NAD+ is regenerated for use in glycolysis when pyruvate, the end product of glycolysis, serves as an electron acceptor for oxidizing NADH. Pyruvate, the electron acceptor, is an organic molecule.

Therefore, the correct option is option C. Analysis of the other options Option A: The electron acceptor must be oxygen This describes aerobic respiration.

Fermentation is specifically an anaerobic process.

Option B: The electron acceptor must be an inorganic molecule Fermentation is distinct because it uses an organic byproduct of the pathway itself.

Option D: Carbon must be oxidized The defining characteristic of fermentation is the reduction of an organic molecule to recycle coenzymes.

Option E: The redox coenzyme must be reduced Actually, the coenzyme (NADH) must be oxidized back into NAD+ for the reaction to be successful.

If the coenzyme remained reduced, glycolysis would grind to a halt.

Full explanation

A nucleotide is composed of 3 parts: a 5-carbon sugar (ribose), a phosphate group attached to the C 5’, and a nitrogenous base group attached to the C 1’.

Therefore, the correct answer is option

A) C 1′

Full explanation

Mitochondria are double membrane-bound organelles that can be found in eukaryotic cells.

It is an autonomous organelle that has its own mitochondrial DNA and ribosomes.

It is the site of cellular respiration.

Analysis of the given statements 1.

Site of DNA molecule replication Since it has its own DNA molecule and the machinery, it can perform the DNA replication process.

Therefore, this statement is true. 2.

Site of water molecule synthesis During oxidative phosphorylation of the cellular respiration process, oxygen serves as the final electron acceptor.

It combines with free electrons and protons (H+) to form water (H₂O). 3.

Site of transport via simple diffusion The mitochondrial membranes are selectively permeable.

While many ions and molecules require specific transporters, small, non-polar molecules like oxygen (O₂) and carbon dioxide (CO₂) move across the double membrane via simple diffusion based on their concentration gradients. 4.

Present in autotrophic cells Mitochondria are found in nearly all eukaryotic cells, including those of plants, which are autotrophic cells.

Therefore, all of the given statements are correct.

Full explanation

Independent assortment of chromosomes is an aspect of sexual reproduction that generates genetic variation.

It is the random orientation of pairs of homologous chromosomes at metaphase of meiosis I. Therefore, among the given options, option B correctly describes the process.

Full explanation

Analysis of the given options Option A: The need for adaptation induces heritable variations in individuals of a population Incorrect.

Natural selection occurs through interactions between individual organisms and their environment; individuals do not evolve.

It is the population that evolves over time.

Option B: Populations have a high reproductive potential.

Correct.

Natural selection is a process in which individuals that have certain heritable traits survive and reproduce at a higher rate than do other individuals because of those traits.

Option C: Natural resources are limited Correct.

Natural selection favors traits that increase the chances of surviving and reproducing under environmental challenges, such as a lack of food, predators, or adverse physical conditions.

Option D: Natural selection favors traits that improve individuals’ survival and reproductive success.

Correct.

This is the main idea of natural selection.

Option E: Individuals in a population show heritable variations independently of environmental needs Correct.

This is observation no. 1 of Darwin’s theory.

Full explanation

Glycogen is a storage form of a polysaccharide that can be found in animals.

Vertebrates store glycogen mainly in the liver and muscle cells.

Compared with muscle cells and the liver, the liver has a higher glycogen concentration by weight.

Therefore, among the given structures, the liver contains the greatest amount of glycogen deposits.

Full explanation

Generally, substances that have similar polarity and size tend to mix homogeneously.

In the given options, Dinitrogen and Dioxygen are both non-polar, diatomic molecules with comparable sizes and masses.

In contrast, the other pairs involve different phases (solid/liquid) or conflicting polarities (polar water vs. non-polar oil/sulfur), which prevent them from forming a stable homogeneous mixture under these conditions.

Therefore, the correct option is option

E) Dinitrogen and dioxygen

Full explanation

Question: percentage composition by volume of the gaseous mixture CH₄(g) + 2 O₂(g) → CO₂(g) + 2 H₂O(g) According to the equation, all reactants and products are in a gaseous state; therefore, we need to determine the volume of each gas to calculate the percentage composition.

Given: Volume of CH₄(g) = 20 ml, Volume of O₂(g) = 80 ml The stoichiometric ratio is 1:2 for CH₄: O₂ from the equation.

So, if 20 ml of CH₄ is used, 40 ml of O₂ would be needed.

Since it is given that 80 ml of O₂ is there, O₂ is the reactant in excess, and CH₄ is the limiting reactant.

The limiting reactant quantity is used to figure out the quantity of the products.

Stoichiometric ratio for CH₄ and CO₂ is 1:1.

Therefore, if 20ml of CH₄ is used, 20ml of CO₂ would be released.

Stoichiometric ratio for CH₄ and H₂O is 1:2.

Therefore, if 20ml of CH₄ is used, 40ml of H₂O would be produced.

After the reaction, the entire volume of CH₄ and 40 mL of O₂ are consumed.

Total gas volume after reaction = 40ml of O₂ + 20ml of CO₂ + 40ml of H₂O = 100ml Now, we can calculate the percentage composition for each gas.

Percent composition of O₂ = 40 ml/100 ml × 100%=40% Percent composition of CO₂ = 20 ml/100 ml × 100%=20% Percent composition of H₂O = 40 ml/100 ml × 100%=40% Therefore, the correct option is option B

Full explanation

Atoms or ions with the same electronic configurations are said to be isoelectronic to each other.

In this case, we can check the number of electrons for each species and choose the ion or element that has the same number of electrons as N³⁺.

Numbers of electrons in N³⁺ = 7 - 3 = 4 Number of electrons in C = 6 Number of electrons in F = 9 Number of electrons in P³⁺ = 15 – 3 = 12 Number of electrons in O^2- = 8 + 2 = 10 Number of electrons in Be = 4 Therefore, a species that is isoelectronic with N³⁺ is

E) Be

Full explanation

Option A: Atomic radius does not decrease down the group.

It increases.

Therefore, this is an incorrect option.

Option B: An increase in atomic radius down the group increases the distance between the positive nucleus and the negative electron, weakening the electrostatic pull.

This results in decreasing electronegativity down the group.

Therefore, this is a correct option.

Option C: Incorrect.

Tendency to lose electrons actually increases down the group.

(Ionization energy) Option D: Incorrect.

The attractive force actually decreases due to increased distance.

Option E: Incorrect.

Metallic character increases as you go down the group. ────────────────────────────────────────────

Full explanation

To find a pair with the greatest ionic character, we have to analyse the electronegativity difference between the pair.

The greater the electronegativity difference, the greater the ionic character is.

Another fact to consider is that non-metals usually have a lower electronegativity difference than the non-metal and metal pair.

Therefore, we can first exclude pairs containing non-metals.

Among the given options, B and E are non-metal pairs, so we can exclude them.

According to the electronegativity trend, electronegativity decreases down the group and increases across the period from left to right.

Because boron and hydrogen are right across from each other in the periodic table, their electronegativity difference is gonna be about the same.

Among the two pairs Li, O and Al, O, Li has less electronegativity than Al.

Therefore, the electronegativity difference would be greater with Li than with Al.

As a result, Li and O pair will have the greatest electronegativity difference, thus expressing the greatest ionic character.

Full explanation

All the given options are metal-non-metal pairs that form ionic bonds.

In ionic bonding, the formula is determined by balancing the charges between the cations and anions.

CaCl: Ca (metal) forms a positive ion with a 2⁺ charge, and Cl (non-metal) forms a negative ion with a 1^- charge.

According to the given formula, since the charges do not cancel out (+2 and -1), the formula is not a stable one.

CaO: Ca forms a positive ion with a 2⁺ charge, and O forms a negative ion with a 2- charge.

Since the charges cancel each other out, this represents the formula of a stable compound.

Ca₂Cl: Ca forms positive ions with a 2⁺ charge (2 Ca atoms – 4⁺ charge), and Cl forms a negative ion with 1^- charge.

Since the charges do not cancel each other out, this formula is not stable.

NaCl₂: Na forms a positive ion with a 1⁺ charge, and Cl forms a negative ion with a 1^- charge (2Cl^- - 2^- charge).

Since the charges do not cancel each other out, this formula is not stable.

Therefore, the correct option is option B.

Full explanation

To balance the given equation, we will check out the metals first.

According to the equation, Cu in the reactants and Cu²⁺ in the products are in a 1:1 ratio.

Using this fact, we can exclude options C, D, and E, whose stoichiometric ratios for a and d are not 1:1.

Next, we check the nitrogen ratio in reactants and products.

They (c and e) need to be in a 1:1 ratio.

Using this fact, we can exclude option A. Therefore, the correct option is option B.

Full explanation

Given: mass of glucose = 18g, molar mass of glucose = 180g/mol, volume of solution/water = 10L The answer options are in molarity (mol/dm3).

Therefore, we need to convert the mass of glucose into mol and the volume of water into dm3.

Mole of glucose = 18 g/(180g/mol)=0.1 mol Volume of solution (water) = 10L = 10 dm3 Molarity of solution = 0.1 mol/10 dm³=0.01 M

Full explanation

Temperature: An increase in temperature increases the rate of reaction by causing particles to move faster, increasing the likelihood of collisions and the formation of more products.

Concentration: An increase in reactant concentration can also increase the reaction rate.

Having more particles in the same volume results in more frequent collisions.

According to collision theory, more frequent collisions increase the probability of successful, energetic, and properly oriented collisions, thereby accelerating the overall reaction.

Pressure: If the reactants are in a gaseous state, increasing the pressure can increase the reaction rate by concentrating particles in a smaller volume, leading to more frequent collisions.

However, this does not work for solid or liquid reactants.

Surface area: A greater surface area can increase the reaction rate.

When a solid is crushed into powder, new surfaces get exposed.

A much larger number of particles is available to react simultaneously, leading to the formation of more products and thereby increasing the reaction rate.

Catalyst: Catalysts are substances that increase the rate of reaction without being consumed.

Therefore, any reaction will increase in rate when a catalyst is added.

Among the given options, the one that correctly describes the combination that increases the reaction rate is option C.

Full explanation

When water is subjected to a strong oxidizing agent, the oxygen atoms in water (which are in the -2 oxidation state) are oxidized.

Oxidation is the loss of electrons; since oxygen in water cannot be oxidized further than to its elemental state in this context, it loses electrons to form oxygen gas, where its oxidation state becomes 0.

Therefore, the correct answer is option

B) O₂

Full explanation

Reaction to neutralize a monoprotic acid with NaOH XH + NaOH → NaX + H₂O Given pH of monoprotic acid = 2 Therefore, concentration of H+ ion = (10^-2 mol)/dm³ Given volume of solution = 10L = 10 dm³ Mole of H+ ion = concentration × volume=(10^-2 mol)/dm³× 10 dm³=0.1 mol According to the equation, the mole ratio of XH and NaOH is 1:1.

Therefore, 0.1 mole of XH (monoprotic acid) needs 0.1 mole of NaOH to be neutralized completely.

Molar mass of NaOH (given) = 40 g/mol Mass of NaOH needed = mole × molar mass= 0.1 mol × 40g/mol=4 g

Full explanation

Isomers are compounds with the same molecular formula but differ in their structural arrangement.

Pentane has molecular formula C₅H₍₁₂₎ (C_nH_(2n+2)).

We need to find the option with the same molecular formula as pentane.

2-pentanone has molecular formula C₅H₍₁₀₎O.

2-pentene has molecular formula C₅H₍₁₀₎ (C_nH_(2n)).

2-methylbutane has molecular formula C₅H₍₁₂₎ (C_nH_(2n+2)).

2-methylpentane has molecular formula C₆H₍₁₄₎ (C_nH_(2n+2)).

Cyclopentane has molecular formula C₅H₍₁₀₎ (C_nH_(2n)).

Among the given options, only option C has the same molecular formula as pentane.

Therefore, it is the isomer of pentane.

Full explanation

The Ideal Gas Law is defined as: PV = nRT In this specific scenario, we are told that: Volume (V) is constant (it’s a rigid 1 L container).

Temperature (T) is returned to the initial value (40 °C).

The Gas Constant (R) is always constant.

Because of the 1:1 molar ratio between the reactant gas (O2) and the product gas (CO2), the total number of moles of gas (n) in the container remains exactly the same before and after the reaction.

Conclusion Since n, V, and T are all unchanged, the pressure (P) must also remain unchanged.

The correct answer is

E) Unchanged.

Full explanation

The value of n (1st quantum number) limits the values of l (2nd quantum number), which in turn limit the values of ml (3rd quantum number).

The spin quantum number does not depend on anything.

Therefore, among the given options, the wrong option is option B)

Full explanation

Since a strong electrolyte is given, when it is dissolved in water, it will completely dissociate into Ca²⁺and Br^- ions.

CaBr₂ → Ca²⁺ + 2Br^- To get the concentration of Br- ions, we have to figure out the concentration of CaBr₂ first.

Mole of CaBr₂ = mass of CaBr₂/molar mass of CaBr₂ = 400g/(200g/mol)=2 mole Volume of CaBr₂ = 10L = 10 dm3 Concentration of CaBr₂ = 2 mole/10 dm³=0.2 M According to the equation, the mole ratio of CaBr₂ and Br^- is 1:2.

Therefore, 0.2M of CaBr₂ will produce 0.4 mol of Br^- ions.

Full explanation

Let's solve this step by step.

Given: n=6000 rpm r=12.5 cm=0.125 m g=10 m/s²

Step 1: Convert rotational speed to angular velocity Express n in revolutions per second, then convert to rad/s: n^'=6000/60=100 rev/s ω=2πn^'=2π×100=200π rad/s

Step 2: Calculate the centripetal acceleration a_c=ω²r a_c=(200π)²×0.125 a_c=40 000π²×0.125 a_c=5000π²~50 000 m/s² (Note, π² can be taken as approximately equal to 10)

Step 3: Express in terms of g a_c/g~50 000/10~5000

So, the correct answer is option E.

Full explanation

Let's solve this step by step.

Given: Horizontal velocity: v_x=12 m/s Final speed on impact: v=20 m/s g=10 m/s²

Step 1: Find the vertical velocity component on impact Horizontal speed is constant (no air resistance).

Using the resultant speed: v²=v_x²+v_y² v_y²=v²-v_x²=20²-12²=400-144=256 v_y=16 m/s

Step 2: Find the height using kinematics The coin is dropped (initial vertical velocity = 0), so: v_y²=2gh h=v_y²/2g=256/2×10=256/20=12.8 m~13 m

So, the correct answer is option B.

Full explanation

Given: Spring constant: K = 1 N/m Extension: x = 50 cm = 0.5 m Now, apply the elastic potential energy formula.

For an ideal spring, the work done equals the elastic potential energy stored: W=1/2Kx² W=1/2×1×(0.5)² W=1/2×0.25 W=0.125 J

So, the correct answer is option A.

Full explanation

Let's solve this step by step.

The setup: all three glasses are identical, with cross-sectional area A and water level height H. Define: W_g = weight of an empty glass.

V_w = A×H = the total volume below the waterline in Glass 1 (all water). ρ_w = density of water.

The critical idea: because all three water levels are the same, the total volume below that waterline is V_w in every glass — shared between water and any objects.

Glass 1 — pure water: here, ρ_wgV_w is simply the weight of the water (density × g × volume).

So in glass 1, P₁ is weight of glass + weight of water.

P₁ = W_g + ρ_wgV_w

Glass 2 — floating cork: let V_c = volume of cork that sits below the waterline.

The water only fills the remaining space: water volume in Glass 2 = V_w - V_c.

So in glass 2, P₂ is weight of glass + weight of water + weight of cork.

P₂ = W_g + ρ_wg(V_w-V_c) + m_cg Now use the floating condition (Archimedes): a floating object displaces water equal to its own weight: ρ_wgV_c = m_cg, so ρ_wV_c = m_c.

Substituting back: P₂ = W_g + ρ_wg(V_w-V_c) + ρ_wV_cg = W_g + ρ_wgV_w - ρ_wgV_c + ρ_wV_cg = W_g + ρ_wgV_w = P₁.

The cork's weight is exactly cancelled by the water it displaced.

So P₂ = P₁.

Glass 3 — steel ball on the bottom: let V_b = volume of the ball (fully submerged).

Water fills the rest, so in glass 3, P₃ is weight of glass + weight of water + weight of steel ball.

P₃ = W_g + ρ_wg(V_w-V_b) + m_bg Steel is far denser than water, so m_b = ρ_(steel)V_b ≫ ρ_wV_b, meaning m_bg - ρ_wV_bg > 0, so P₃ > P₁.

Hence, the conclusion is: P₃ > P₁ = P₂.

The key takeaway: a floating object "hides" its full weight in the displaced water, so the scale reads the same as if it weren't there.

A sunken object (denser than water) doesn't fully compensate — it weighs more than the water it pushed out, so the scale reads heavier.

So, the correct answer is option E.

Full explanation

Given: Capacitance: C = 50 μF = 50 × 10^-6 F Voltage: V = 4 kV = 4 × 10³ V Now, apply the formula for energy stored in a capacitor: E=1/2CV² E=1/2×(50×10^-6)×(4×10³)² E=1/2×(50×10^-6)×(16×10⁶) E=1/2×800 E=400 J

So, the correct answer is option B.

Full explanation

Let's solve this step by step.

Given: Reference line: y=3-x→slope m₁=-1 Required line passes through: (1, 1)

Step 1: Find the slope of the required line For two perpendicular lines, their slopes satisfy: m₁×m₂=-1 (-1)×m₂=-1 m₂=1

Step 2: Write the equation of the required line Using the point-slope form with slope 1 through (1, 1): y-1=1×(x-1) y=x

So, the correct answer is option A.

Full explanation

Let's solve this step by step.

Step 1: Express 1/8 as a power of 1/2 =>1/8=1/2³

Step 2: Rewrite the inequality with a common base =>1/(2^( 1-x))<1/2³

Step 3: Apply the rule for a decreasing exponential base Since the base 1/2 lies between 0 and 1, the function (1/2)^t is strictly decreasing.

The inequality direction therefore reverses when comparing exponents: =>1-x>3 =>-x>2 =>x<-2

So, the correct answer is option B.

Full explanation

Let's solve this step by step.

Step 1: Find the x-intercept of the line Set y=0: =>0=8x-4 =>8x=4 =>x=1/2 The line crosses the x-axis at (1/2,  0).

Step 2: Find the y-intercept of the line Set x=0: =>y=8(0)-4=-4 The line crosses the y-axis at (0, -4).

Step 3: Calculate the area of the triangle The triangle has vertices (0,  0), (1/2,  0), and (0, -4).

Area is always a positive quantity: =>Area=1/2×∣base∣×∣height∣ =>Area=1/2×1/2×∣-4∣ =>Area=1/2×1/2×4 =>Area=1

So, the correct answer is option D.

Full explanation

Let's solve this step by step.

Given: Rectangle sides: a=6, b=12

Step 1: Find the diameter of the circumscribed circle For a rectangle, the diagonal equals the diameter of its circumscribed circle: =>d=√(a²+b²)=√(6²+12²) =>d=√(36+144)=√(180)

Step 2: Find the radius =>r=d/2=√(180)/2=3√(5)

Step 3: Calculate the area of the circle =>A=πr²=π×(3√(5))² =>A=π×9×5 =>A=45π

So, the correct answer is option D.

Full explanation

Let's solve this step by step.

Given: P(6)=1/3 Faces 1–5 each have equal probability

Step 1: Find the probability of each of the five remaining faces =>P(1)+P(2)+P(3)+P(4)+P(5)=1-1/3=2/3 =>P(each face 1-5)=(2/3)/5=2/15

Step 2: Find the probability of rolling an even number Even faces: 2, 4, and 6: =>P(even)=P(2)+P(4)+P(6) =>P(even)=2/15+2/15+1/3 =>P(even)=2/15+2/15+5/15 =>P(even)=9/15=3/5

So, the correct answer is option E.

Full explanation

Let's solve this step by step.

Given: Mass per stone: m=1 kg Table height: h=1 m Total energy available: E=4.2 kJ=4200 J g=9.8 m/s²

Step 1: Calculate the energy required to lift one stone =>E_(stone)=mgh=1×9.8×1=9.8 J

Step 2: Calculate the number of stones that can be lifted =>n=E/E_(stone)=4200/9.8~428.6~430

So, the correct answer is option B.

Full explanation

Let's solve this step by step.

Given: Inequality: sinx>sin5π/18, 0<x<π Note: 5π/18=50°, π-5π/18=13π/18=130°

Step 1: Recall the behaviour of sinx on (0, π) sinx is positive throughout (0, π), increases on (0, π/2), and decreases on (π/2, π).

It is symmetric about x=π/2, so: =>sin5π/18=sin(π, 5π/18)=sin13π/18

Step 2: Determine the solution set sinx>sin5π/18 holds for x strictly between the two angles where sinx=sin(5π/18): =>5π/18<x<13π/18

So, the correct answer is option A.

Full explanation

Let's solve this step by step.

Given: Expression: f(x,y)=6x²-2y² Domain: x,y∈[0,1]

Step 1: Determine the strategy for maximisation The expression has two parts: 6x² is maximised by choosing x as large as possible →x=1 -2y² is maximised (least negative) by choosing y as small as possible →y=0

Step 2: Calculate the maximum value =>f(1,0)=6(1)²-2(0)² =>f(1,0)=6-0=6

So, the correct answer is option C.