Chemistry Answers

1. Which statement below is NOT consistent with the Kinetic Molecular Theory (KMT) *

A. There is space between particles.

B. Matter is made of particles that are constantly in motion.

C. The amount of kinetic energy in a substance is related to its temperature.

D. Phase changes do not happen when the temperature of the substance changes sufficiently

2. Which of the following solutes will cause the highest elevation in the boiling point?

A. NaCl

B. KNO3

C. CaCl2

D. Table Sugar

1. Which is not a colligative property? *

A. Freezing point depression

B. Boiling point elevation

C. Osmotic Pressure

D. Vapor pressure

2. Which is correct about the boiling point of a 1 m aqueous solution of sucrose (342 g/mol) and a 1 m aqueous solution of ethylene glycol (62 g/mol)? Considering that both solutions are non-electrolyte. *

A. sucrose solution boils at higher temperature as it has more solute particles than ethylene glycol solution

B. ethylene glycol solution boils at higher temperature as it has less solute particles than sucrose solution

C. exhibit the same boiling point because each solution has one mole of solute particles (molecules) per kilogram of solvent.

D. ethylene glycol solution and sucrose solution when exposed at higher temperature has both equal amount of solute particles per kilogram of solvent.

1. Which is not true about entropy? *

A. It is denoted by the symbol S

B. It is a measure of the randomness or disorder of a system.

C. It is a measure of how much energy is unavailable for conversion into work.

D. A positive value of a change in entropy indicates that the final state is less random than the initial state.

2. What happens to water molecules when cooled? *

A. The forces between molecules break.

B. The water molecules become excited.

C. The water molecules slide past each other.

D. The water molecules become fixed in position.

3. Which of these is a reason why surface area of reactants is increased? *

A. To stabilize the reaction

B. To speed up the reaction

C. To prevent a compound from forming

D. To produce lesser amount of products

4. Which of these is a reason why surface area of reactants is increased? *

A. To stabilize the reaction

B. To speed up the reaction

C. To prevent a compound from forming

D. To produce lesser amount of products

1. How do exponents (orders) in rate laws compare to coefficients in the balanced equations? *

A. They are ratio to one another.

B. They are directly proportional to each other.

C. The exponents and coefficients are the same.

D. The exponents do not have any relation to the coefficients.

2. Which statement about enthalpy is true? *

A. Specific heat capacity is the same for all liquids.

B. Some substances have a negative specific heat capacity.

C. The sign of ΔH is always negative in exothermic reactions.

D. Heat is given off to the surroundings in endothermic reactions.

3. When acetic acid is added to the aqueous solution of benzene, the ________________________ *

A. Freezing point is raised

B. Freezing point is lowered

C. Boiling point does not change

D. Freezing point does not change

1. A semipermeable membrane allows

A. Only solute particles through

B. Only solvent particles through

C. Neither solute nor solvent particles

D. Both solute and solvent particles through

2. When you place a straw into a glass of water, the water seems to climb up the straw before you even place your mouth on the straw. Which property of water is related to this phenomenon? *

A. Water has high specific heat.

B. Water has a high heat of vaporization.

C. Water is a liquid at normal physiological temperature.

D. Water molecules are adhesive; they form H-bonds with polar surfaces.

3. Which statement is true about catalysts? *

A. They speed up the reaction.

B. They are unrecovered at the end of the reaction.

C. The amount of catalysts decreases as the reaction continues.

D. They can slow down the reaction by consuming the reactants.

Calculate the number of chloride ions in 200 cm cube of 0.5 mol magnesium chloride solution

. Calculate HCV and LCV of a fuel, whose composition by mass is as follows;

Carbon – 90%, Hydrogen – 90%, Sulphur – 90% and reminder being Ash

At a certain speed, the root-mean-square-speed of the molecules of hydrogen in a sample 

of gas is 1055 ms-1

. Compute the root-mean square speed of molecules of oxygen at the 

same temperature.

C6H12O6 +6O2 --> 6CO2 +H2O

If 54.1 grams of CO₂ is produced in the reaction above, how many grams of H₂O are produced in this reaction?

How many grams of oxygen are produced in the decomposition of 45.3g of potassium chlorate (KClO₃)?