Chemistry Past Questions and Answers

When a current I was passed through an electrolyte solution for 40 minutes, a mass X g of a univalent metal was deposited at the cathode. What mass of the metal will be deposited when a current 2I is passed through the solution for 10 minutes?

A X/4 g
B X/2 g
C 2X g
D 4X g

Question 27:

RS_(aq) + HF_(aq) â†’ RF_(s) + HS_(aq)
Î”H = -65.7 kj mol^(-1).
From the equation above, it can be deduced that

A The heat content of the reactants is lower than that of the products
B The heat content of the reactants is higher than that of the products
C The reaction is slow
D A large amount of heat is absorbed

Question 28:

Which of the following statement is true of the electrochemical series?

A Electropositivity of metals increase down the series
B Electropositivity of non-metals decrease down the series
C Electronegativity of non-metals decrease down the series
D Electropositivity of metals decreases down the series

Question 29:

The gas that will form a white precipitate with acidified silver trioxonitrate (v) is

A NH₃
B SO₂
C CO₂
D HCL

Question 30:

Chlorine, bromine and iodine resemble one another in that they

A Dissolve in alkalis
B React violently with hydorgen without heating
C Are liquids
D Displace one another from solutiions of their salts