JAMB Chemistry Past Questions & Answers - Page 235

1,171.

A certain industrial process is represented by the chemical equation 2A(g) + B(g) \(\to\) C(g) + 3D(g) \(\Delta\)H = X kJmol-1. Which of the following conditions will favour the yield of the products?

A.

increase in temperature, decrease in pressure

B.

increase in temperature, increase in pressure

C.

decrease in temperature,increase in pressure

D.

decrease in temperature, decrease in pressure

E.

constant in temperature, increase in pressure

Correct answer is A

No explanation has been provided for this answer.

1,172.

A correct electrochemical series can be obtained from K, Na, Ca, Al, Mg, Zn, Fe, Pb, H, Cu, Hg, Ag, Au by interchanging?

A.

Al and Mg

B.

Zn and Fe

C.

Zn and Pb

D.

Pb and H

E.

Au and Hg

Correct answer is A

The electrochemical series, also known as the activity series, is a list of metals listed in order of decreasing reactivity or in order of decreasing ease of oxidation. 

Magnesium comes before Aluminium in the series

1,173.

If the ONLY pollutants found in the atmosphere over a city are oxides of nitrogen, suspended lead compounds. carbon monoxide and high levels of methane, the probable source(s) of the pollution must be?

A.

automobile exhaust and biological decomposition

B.

combustion of coal and automobile exhaust

C.

biological decomposition only

D.

combustion of coal, automobile exhaust and biological decomposition

E.

combustion of coal and biological decomposition

Correct answer is B

No explanation has been provided for this answer.

1,174.

What is the formula of sodium gallate if gallium (Ga)shows an oxidation number of + 3?

A.

NaGaO3

B.

Na2Ga(OH)3

C.

NaGa(OH)3

D.

NaGa(OH)4

E.

NaGaO

Correct answer is D

No explanation has been provided for this answer.

1,175.

X + Y = Z is an equilibrium reaction. The addition of a catalyst?

A.

increase the amount of Z produced in a given time

B.

increases the rate of change in concentrations of X, Y and Z

C.

increases the rate of disapearance of X and Y

D.

increases the rate of the forward reaction

E.

decreases the amounts of X and Y left after the attainment of equilibrium

Correct answer is B

No explanation has been provided for this answer.