Chemistry Past Questions and Answers

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

Question 402:

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

Question 403:

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

Question 404:

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

Question 405:

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