Consider the following exothermic reaction
2SO_2(g) + O_2(g) ↔ 2SO_3(g)
If the temperature of the reaction is reduced from 800°C to 500°C, an no other change takes place, then

A. the reaction rate increases

B. concentration of SO₃ decreases

C. concentration of SO₃ increases

D. SO₂ gas becomes unreactive

E. O₃ gas becomes unreactive

If excess zinc is added to a bluish green solution of copper (II) sulphate, and the excess zinc filtered off after completion of reaction, a colourless solution is obtained because

A. both zinc and copper are metals

B. the sulphate radical and the zinc ion are divalent

C. zinc is more electropositive than copper

D. both zinc and copper form depositive ions in solution

E. zinc is a reducing agent

Three solutions contain carbonate, sulphate and sulphide ions respectively. One test that will identify just ONE of them completely is by addition to each of them of

A. barium chloride solution

B. dilute hydrochloric acide

C. lead nitrate solution

D. calcium chloride solution

E. sodium hydroxide solution

Two gas cylinders contain ethylene (ethene) and acetylene respectively. One test which can be used to distinguish between them is by

A. passing each gas through bromine water

B. passing each gas through dilute potassium permanganate solution

C. passing each gas through silver nitrate solution

D. treating each gas catalytically with excess hydrogen gas

Consider the following equation H2O + 2Fe2+ + Cl2 ↔ 2Fe3+ + 2Cl- + H2O. Which behaves as an oxidizing agent?

A. Fe²⁺

B. Cl₂

C. Fe³⁺

D. Cl^-

E. H₂O

If hydrogen sulphide gas is passed into a solution of a pure iron chloride, a yellow deposit appears. If the deposit is filtered, a pale green solution is left behind. The pale green solution is

A. dilute sulphuric acid

B. dilute hydrochloric acid

C. unreacted hydrogen sulphide in water

D. iron (III) chloride

E. Iron (II) chloride

Which of the following changes is physical?

A. Adding iron filing to aerated water

B. Adding sodium metal to water

C. Cooling a solution of Iron (II) sulphate to obtain the hydrated salt

D. Cooling water to obtain ice

E. Burning the domestic gas (Utilgas) for cooking

By means of filtration, one component can be obtained pure from an aqueous mixture of sodium chloride and

A. potassium nitrate

B. sand

C. lead nitrate

D. sugar (glucose)

E. starch

In titration involving sodium hydroxide and dilute hydrochloric acid, where would you place the base?

A. in the beaker

B. in the conical flask

C. in a burette

D. in the standard flask

E. in the measuring cylinder

A gas jar was inverted over burning yellow phosphorus floating over water in a beaker. After burning, the water level was found to rise in the gas jar. The water level rises because

A. pressure inside the gas jar is greater than pressure outside it

B. the air in the gas jar had been used up by burning

C. oxygen in the gas jar had been used up by burning

D. nitrogen in the gas jar had been used up by burning

E. the temperature in the jar had risen considerably