Which of the following is a redox reaction?

A. KCI_(aq) + H₂SO_4(aq) → KHSO_4(aq) + HCI_(aq)

B. 2FeBr_2(aq) + Br_4(aq) → 2FeBr_3(aq)

C. 3AgNO_(aq) + FeCl_3(aq) → 3AgCl_(aq) + Fe(NO₃)_3(aq)

D. H₂CO_3(aq) → H₂O_(I)2- + CO_2(g)

If an equilibrium reaction has ∆H < O, the reaction will proceed favorably in the forward reaction at?

A. low temperatures

B. high temperatures

C. all temperatures

D. all pressures

Which of the following processes leads to increase in entropy?

A. Mixing a sample of NaCl and sand

B. Condensation of water vapour

C. Boiling a sample of water

D. Cooling a saturated solution

Which of the following equilibria is shifted to the right as a result of an increase in pressure?

A. H_2(g) + I_2(g) 2HI_(g)

B. 2NO_2(g) N₂O_4(g)

C. PCl_5(s) PCl_3(s) + Cl_2(g)

D. 2O_3(g) 3O_2(g)

In the industrial production of hydrogen from natural gas, carbon (IV) oxide produced along with the hydrogen is removed by?

A. washing with water under pressure

B. passing the mixture into lime water

C. using ammoniacal copper (l) chloride

D. drying over phoshorus (V) oxide

Sulphur exists in six forms in the solid state. This property is known as?

A. isomerism

B. allotropy

C. isotopy

D. isomorphism

A gas that will turn orange potassium heptaoxodichromate (lV) solution to clear green is?

A. sulphur (lV) oxide

B. hydrogen sulphide

C. sulphide (lV) oxide

D. hydrogen chloride

Which of the following ions will give a white precipitate with aqueous NaOH and soluble in excess of the base?

A. Ca²⁺

B. Mg²⁺

C. Zn²⁺

D. Cu²⁺

In the extraction of iron in the blast furnace, limestone is used to?

A. release CO₂ for the reaction

B. reduce the iron ore

C. increase the strenght of the iron

D. remove impurities

Which of the following compounds will impart a brick-red colour to a non-luminious bunsen flame?

A. NaCl

B. LiCl

C. CaCl₂

D. MgCl₂