1. Molarity is to moles of solute over liters of solution as molality

is to
A. molar concentration over molal concentration.
B. moles of solute over kilograms of solvent.
C. molal concentration over molar concentration.
D. moles of solute over moles of solvent.

2. In describing an equilibrium reaction involving hydrogen gas, iodine gas, and hydrogen
iodide gas, all of the statements about equation Q = [HI]2 � [H2] [I2] are true except for
which one?
A. Any solids are omitted from equilibrium expressions.
B. The brackets refer to “concentration of . . . ”
C. Coefficients from the original balanced equation (in this case, 2 HI) become exponents.
D. The products go to the denominator, and the reactants go to the numerator.

3. If the angle of collision between molecules A and B in a reaction is favorable, reaction
energy is less than when the angle of collision is unfavorable. If you look up the typical
activation energy for a given reaction in a table, the value you see will be for
A. minimum activation energy.
B. maximum activation energy.
C. average activation energy.
D. the range of values between minimum and maximum activation energy.

4. If a catalyst is used to alter the reaction rate of A + B → AB, we can expect a/an
A. increase in ΔH.
B. increase in the activation energy that initiates the reaction.
C. decrease in ΔH.
D. decrease in the activation energy that initiates the reaction.

What is your thinking on this?

1.D

2.B
3.B
4.A

I've been reviewing these questions for a while. The first one makes no sense. The wording is really strange. They all are worded weird. I just need them explained in a better way. Can you help?

1. The correct answer is B. Molality is defined as the moles of solute divided by the kilograms of solvent. It is different from molarity, which is defined as the moles of solute divided by the liters of solution.

2. The correct answer is A. According to the equation Q = [HI]^2 * [H2] * [I2], any solids that are present in the equilibrium reaction are not included in the equilibrium expressions. Only the concentrations of the gaseous reactants and products are included.

3. The correct answer is A. When the angle of collision between molecules A and B in a reaction is favorable, the reaction energy is lower compared to when the angle of collision is unfavorable. The typical activation energy value that you see in a table is for the minimum activation energy required for the reaction to take place.

4. The correct answer is D. If a catalyst is used to alter the reaction rate of A + B → AB, we can expect a decrease in the activation energy that initiates the reaction. A catalyst provides an alternative reaction pathway with a lower activation energy, allowing the reaction to occur more readily. It does not affect the overall change in enthalpy (ΔH) of the reaction.