Jamb chemistry

During the electrolysis of copper II sulphate between platinum electrodes, if litmus solution is added to the anode compartment,

• • the litmus turns blue but no gas is evolved

• • the litmus turns red and oxygen is evolved

• • the litmus turns red and then becomes colourless

• • the litmus turns blue and hydrogen is evolved

Tags

electrochemistry

What amount of mercury would be liberated if the same quantity of electricity that liberates 0.65g of zinc is applied?

• • 2.01g

• • 1.00g

• • 4.02g

• • 8.04g

Tags

electrochemistry

In the reaction between sodium hydroxide and sulphuric acid solutions, what volume of 0.5 molar sodium hydroxide would exactly neutralise 10cm3 of 1.25 molar sulphuric acid?

• • 10cm³

• • 20cm³

• • 25cm³

• • 50cm³

Tags

qualitative and quantitative analysis

What volume of gas is evolved at S.t.p if 2g of calcium trioxocarbonate (IV) is added to a solution of hydrochloric acid?
[Ca = 40, C = 12, O = 16, Cl = 35.5, H = 1 Molar volume of a gas at s.t.p = 22.4 dm3

• • 2240 cm²

• • 112 cm²

• • 224 cm²

• • 448 cm²

Tags

qualitative and quantitative analysis

X + Y → Z. The rate equation for the chemical reaction above is −Δx/Δt = K[X]²/[Y].
The overall order of the reaction is?

• • 0.0

• • 1.0

• • 2.0

• • 3.0

Tags

chemical combination

How many unpaired electron(s) are there in the nitrogen sub-levels?

• • 3

• • 2

• • 1

• • none

Tags

chemical combination

Which of the following statements is NOT correct?

• • The average kinetic energy of a gas is directly proportional to its temperature

• • At constant temperature, the volume of a gas increases as the pressure increases

• • The pressure of a gas is directly proportional to the density.

• • The temperature of a gas is directly proportional to its volume

Tags

properties of gases

A gas exerts pressure on its container because?

• • the molecules of a gas collide with the walls of the container

• • some of the molecules are moving faster than others

• • of the collisions of the molecules with each other

• • of the mass of the molecules of the gas

Tags

properties of gases

H2(g) + Br2(g) → 2HBr(g)
The above reaction is carried out at 2500C. ΔH is -72 kJ mol-1 and ΔS is - 106 J mol-1K-1, the reaction will?

• • not proceed spontaneously at the given

• • proceed spontaneously at the given temperature

• • proceed in the reverse direction at the given temperature

• • proceed spontenously at lower temperature

Tags

energy and chemical reactions

Two equal bulbs, one containing ammonia and the other nitrogen are opened mouth - to - mouth to each other at room temperature. The entropy in the mixture of gases is likely to?

• • remain unchange

• • increase

• • decrease

• • change

Tags

energy and chemical reactions