On evaporation to dryness, 250 cm³ of saturated solution of salt X with relative molar mass 101 gave 50.5g of the. What is the soluility of the salt?

A. 1.0 mol dm^-3

B. 20 mol dm^-3

C. 4.0 moldm^-3

D. 5.0 moldm^-3

Consider the following reaction equation: X_(g)
+ Y_(g) ⇌ XY_(g); ∆H = + 220KJ mol^-1 If the temperature of the system is increased, the

A. backward reaction would be favoured

B. forward reaction would favoured

C. reaction would stop

D. reaction would be at equilibrium

What is the value of n in the following equation? Cr₂O₇^2- + 14H⁺ + ne^- → 2Cr ³⁺ + 7H₂O

A. 2

B. 3

C. 6

D. 7

What mass of copper would be formed when a current of 10.0 A is passed through a solution of CuSO₄ for 1 hour? [Cu = 63.5; 1F = 96500C]

A. 5.9 g

B. 11.8 g

C. 23.8 g

D. 47.3 g

Which of the following metals could be used as sacrifical anode for preventing the corrosion of iron?

A. Copper

B. Lead

C. Magnesium

D. Silver

Consider the following electrochemical cell notation: M(s) / M2+ (aq)// H+ (aq)/ H2(g). The value of the electrode potential is positive when?

A. electrons flow from the metal electrode, M_(s) to hydrogen electrode, H_2(g)

B. electrons fow from hydrogen electrode, H_2(g) to metal electrode, M_(s)

C. the flow of current is high

D. there is equilibrium between the flow of electrons from the hydrogen electrode, H_2(g) to metal electrode, M_(s)

Which of the following compounds determines the octane rating of petrol?

A. 1,2,3 - trimethlpentane

B. 2,3,5 - trimethyloctane

C. 2,3,5 - trimethylpentane

D. 2,2,4 - trimethylpentane

Which of the following compounds would react with ethanoic acid to give a sweet smelling liquid?

A. Alkane

B. Alkanol

C. Alkanal

D. Alkyne

Which of the following separation techniques would show that black ink is a mixture of chemical compounds?

A. Crystallization

B. Chromatography

C. Filtration

D. Sublimation

The following substances are examples of addition polymer except

A. nylon

B. perspex

C. polyethene

D. polychloroethene