Question

1) 1.95 moles of HBr in 250.0 mL flask is consumed in 1.00 minutes in the gas phase reaction 2 HBr(g) → H₂(g) + Br₂(g) at 150°C.   The rate of reaction is __________ M∙s^-1.

		3.85
		0.0650
		0.0169
		0.260
		0.0860

2)The reaction A → C is found to be zero order. Which of the following will give a linear plot?

		(A) vs. time
		ln(A) vs. time
		1/(A) vs. time
		None of these will be linear.

3)Which of the following is not a colligative property?

		depression of solvent vapor pressure upon addition of a solute to a solvent
		elevation of the boiling point of a solution upon addition of a solute to a solvent
		depression of the freezing point of a solution upon addition of a solute to a solvent
		an increase in the osmotic pressure of a solution upon the addition of more solute
		the increase of reaction rates with increase in temperature

4)

Yeast and sugar are added to champagne to give the sparkle of carbonation. Under what conditions is carbon dioxide gas most soluble?

		low temperature, high pressure
		low temperature, low pressure
		high temperature, low pressure
		high temperature, high pressure
		none of these

5)

In general, the solubility of ________ in water decreases as temperature increases.

		liquids
		solids
		gases
		none of these

6) In a solution, the solvent is:

		always water
		the substance in the greatest amount
		the substance that is dissolved
		always a gas

Answer 1

Q1 Solution :-

Balanced reaction equation is

2HBr ------ > H2   + Br2

1 min = 60 sec

Rate = ½ delta [HBr]/delta T

Molarity of the HBr = 1.95 mol / 0.250 L = 7.8 M

Rate = ½ [7.8M] / 60 sec

Rate = 0.065 Ms-1

Q2 solution

For the zero order reaction a plot of concentration verses time gives the linear plot therefore the correct answer is the

(A).Vs. time that is the first option.

Q3 solution

Elevation in boiling point. Depression freezing point, depression of vapor pressure and osmotic pressure are the colligative properties which depends on the molal concentration of the solution

Therefore the statement provided in the last option that is

Increase in the reaction rate with increase in the temperature is not the colligative property.

Q4 solution

When the temperature is low and pressure is high then gas is more soluble in the liquid therefore the correct answer is the first option

That is low temperature, high pressure

Q5 solution :-

The solubility of the gas decreases with increase in temperature.

Therefore the correct answer is option 3 that is gases

Q6 solution :-

Solvent is the liquid portion of the solution which dissolves the solute therefore the amount of the solvent is higher than the solute

Therefore the correct answer is the option 2 that is

The substance in the greatest amount.