When aqueous ammonia is added to one of the following solutions,a white precipitate which dissolved in excess ammonia is formed Identify the solution.

A. ZnCl_2(aq)

B. Pb(NO₃)_2(aq)

C. CuSO_4(aq)

D. FeSO_4(aq)

Which of the following compounds absorbs moisture from the atmosphere and dissolves in it?

A. FeCI₃

B. MgSO₄.7H₂O

C. Na₂SO ₄

D. KCI

Consider the reaction represented by the equation: 2SO\(_{2(g)}\) + O\(_{2(g)}\) ⇌ 2SO\(_{3(g)}\); ∆H = - 197 kJmol\(^{-1}\). Which of the following conditions will not increase the yield of sulphur (VI) oxide?

A. Increase in temperature

B. Decrease in temperature

C. Increase in pressure

D. Addition of O₂ into the mixture

Electrolysis is applied in the following processes except

A. electroplating

B. extraction of aluminium

C. extraction of iron

D. purification of copper

The oxidation number of iodine in the iodate ion (IO ^-₃) is

A. -5

B. -1

C. +1

D. +5

Metals can be extracted from their ores by a process involving

A. reduction

B. oxidation

C. hydrolysis

D. decomposition

Consider the reaction: 2AI_(s) + 6H⁺ _(aq) → 2AI³⁺ _(aq) + 3H_2(g). What is the total number of moles of electrons transferred from the aluminium atoms to the hydrogen ions?

A. 3

B. 4

C. 5

D. 6

In the reaction represented by the equation. 5Fe ²⁺ _(aq) + MnO^- _4(aq) + 8H⁺ _(aq) → 5Fe³⁺_(aq) + Mn^{2+_(aq) + 4H₂O_(l) which species is reduced?}

A. Fe²⁺

B. MnO^-4

C. H⁺

D. Fe³⁺

Which of the following industrial processes is chlorines not used?

A. Production of polyvinylchloride (PVC)

B. Manufacturing of hydrochloric acid

C. Manufacturing of common salt

D. Manufacturing of domestic bleach

What type of reaction occurs between vegetable oil and plant ash extract?

A. Displacement

B. Dehydration

C. Neutralization

D. Saponiflication