Chemistry Past Questions and Answers

How many moles HCL will be required to react with potassium heptaoxodichromate (VI) to produce 3 moles of chlorine?

A 14
B 12
C 11
D 10

Question 7:

The ratio of the initial to final pressure of a given mass of gas is 1:1.5. Calculate the final volume of the gas if the initial volume was 300 cm³ at the same temperature

A 120 cm³
B 200 cm³
C 450 cm³
D 750 cm³

Question 8:

The partial pressure of oxygen in a sample of air is 452 mm Hg and the total pressure is 780 mm Hg. What is the mole fraction of oxygen?

A 0.203
B 0.579
C 2.030
D 5.790

Question 9:

The fundamental difference between the three states of matter is the

A Shape of their particles
B Number of particles in each state
C Shape of the container they occupy
D Degree of movement of their particles

Question 10:

Which of the following statement is correct about the periodic table?

A Elements in the same period have the same number of valency electron
B The valence electron of the elements in the same period increase progressively across the period
C Elements in the same group have the same number of electron shells
D The non-metallic properties of the elements tend to decrease across each period