Free Printable FIVIZZ: ROAD TO MIDSEM

1.

What is the effect of catalyst on a reversible reaction?

a)

Catalyst increases the product of a reaction

b)

Catalyst increases the equilibrium constant

c)

Catalyst increases the rate of the forward reaction

d)

Catalyst increases both the rate of forward and reverse reaction

2.

$CaCO_3\left(s\right)\ ⇋\ CaO\ \left(s\right)\ +\ CO_2\left(g\right)$
The equilibrium constant, $K_p$ for the above reaction is 319 Pa at 298 K and, $1.8\times10^5$ Pa at 5500 K. Hence, it can be concluded that,

a)

the forward reaction is endothermic

b)

the value of $K_p$ depends on the amount of the $CaCO_3$ used

c)

increasing pressure will increase the yield of $CO_2$

d)

the amount of $CO_2$ produced is not affected by temperature

3.

Which of the following will decrease the $K_c$ for an exothermic reaction?

a)

Increase the temperature

b)

Increase the pressure

c)

Increase the amount of catalyst used

4.

The dissociation constant for an organic acid, HA is $1.4\times10^{-5\ }$ M. Calculate the concentration of $H_3O^+$ ion in 0.01 M HA.

a)

$1.13\times10^3$ M

b)

$2.81\times10^{-3}$ M

c)

$3.74\times10^{-4}$ M

d)

$51.40\times10^{-7}$ M

5.

The degree of dissociation of a weak acid, HA at pH 2.0 is 0.02. What is the value of $K_a$ for HA?

a)

$1.0\times10^{-5}\ mol\ dm^{-3}$

b)

$2.0\times10^{-4}\ mol\ dm^{-3}$

c)

$3.0\times10^{-5}\ mol\ dm^{-3}$

d)

$5.0\times10^{-4}\ mol\ dm^{-3}$

6.

In which of the following reaction, $OH^-$ acts as a conjugate base?

a)

$HCO_3^-\ +\ H_2O\ ⇋\ H_2CO_3\ +\ OH^-$

b)

$HSO_3^-\ +\ H_2O\ ⇋\ H_2SO_3\ +\ OH^-$

c)

$HNO_3^-\ +\ OH^-\ ⇋\ NO_3^-\ +\ H_2O$

7.

Pick the correct statement(s) about salt hydrolysis.

a)

Salt hydrolysis occurs when there is reaction between cations or anions with water

b)

The salt is basic when cations undergo hydrolysis

c)

The salt is acidic when anions undergo hydrolysis

8.

The degree of dissociation of ethanoic acid in liquid ammonia is higher than water. Explain why.

a)

Ethanoic acid is more soluble in liquid ammonia than in water

b)

Ammonia is more polar than water

c)

Ammonia is a stronger acid than water

d)

Ammonia is a stronger base than water

9.

If $500\ cm^3$ 2.0 M HCl is mixed with $1500\ cm^3$ 0.5 M HCl, determine the concentration of the mixture.

a)

0.750 M

b)

0.875 M

c)

1.250 M

d)

2.500 M

10.

The critical temperature of a substance is

a)

the temperature below which it cannot exist as liquid

b)

the temperature below which it cannot be supercooled

c)

the temperature above which it cannot be vapourised

d)

the temperature which is always lower than that triple point temperature

11.

Sucrose is an example of a non-volatile and non-ionising solute in water. Calculate the vapour pressure lowering, at 27 $℃$ , of a solution of 75.0 grams of sucrose, $C_{12}H_{22}O_{11}$ dissolved in 180 g of water. The vapour pressure water at 27 $℃$ is 26.7 torr. Assume the solution is ideal.

a)

0.571 torr

b)

0.585 torr

c)

0.058 torr

d)

0.548 torr

12.

The boiling point of a liquid depends on

a)

its purity

b)

the external atmospheric pressure

c)

the volume of the container used

13.

The standard enthalpy of combustion of C is -393 $kJ\ mol^{-1}$ . Choose the correct value of enthalpy for the reaction,

$2C\ \left(s\right)\ +\ 2O_2\ \left(g\right)\ \rightarrow\ 2CO_2\ \left(g\right)$

a)

-393 kJ

b)

+393 kJ

c)

-786 kJ

d)

+786 kJ

14.

What mass of methane must be burned to raise 2.00 kg of water at 20 $℃$ to 100 $℃$ ? ( $C_{water}$ = $4.18\ J\ g^{-1}\ K^{-1}$ , $\Delta H_{c\ }$ for methane = -890 $kJ\ mol^{-1}$ )

a)

12.0 g

b)

13.5 g

c)

120 g

d)

135 g

15.

When X element combines with Y element, the ionic compound XY formed is very stable if

a)

X has a low ionisation energy

b)

Y^-

is small

c)

The lattice energy of XY is very endothermic

FIVIZZ: ROAD TO MIDSEM - CHEMISTRY 3

Total questions: 15

Worksheet time: 12mins

Similar Resources on Wayground