The following molecules have double covalent bonds between two atoms except?

• A. oxygen
• B. carbon (IV)oxide
• C. ethene
• D. water

(i) State Two assumptions of the kinetic theory of gases

(ii) When some solids are heated, they change directly into the gaseous state. What narne is given to this phenomenon?

(iii) List two substances which exhibit the phenomenon referred to in (a)(ii) above

(iv) Write an expression to show the mathematical relationship between the rate of diffusion of a gas and its vapour density.

(b) Consider the following equilibrium reaction:

3Fe\(_{(s)}\) + 4H\(_2\)O\(_{(g)}\) \(\rightleftharpoons\) FeO\(_3\)O\(_{4(s)}\) + 4H\(_{2(g)}\), \(\Delta\)H = - 150KJ mol\(^{-1}\)

Explain the effect of the following factors on the position of equilibrium: (i) tecrease in temperature; (ii) Increase in pressure; (iii) Removal of hydrogen.

(c) . Three beakers labelled P, Q and S each contained zinc metal of the same mass but in different forms. P contained a length of zinc rod, Q contained zinc dust while S contained zinc foil. 100cm\(^3\) of 5.0 mol dm\(^{-3}\) hydrochloric acid was added to each beaker to react with all the zinc.

(i) State the order in which the reaction came to completion in beakers P,Q and S starting with the fastest.

(ii) Give reason for your answer in (c)(i) above

(iii) Write an equation to represent the reaction between zinc rid the hydrochloric acid.

(d) (i) What is meant by pH of a solution?

(ii)(I) State with reason in each case whether the pH would increase, decrease or remain constant if the following experiments were carried out Neutralizing bench HNO\(_3\);

II. Diluting 25.0 cm\(^3\) of a given NaOH solution to 100.0cm\(^3\) Concentrating a solution of NaCI.

What unit of temperature should be used when applying the ideal gas law?

• A. Fahrenheits
• B. Kelvin
• C. Rankine
• D. Celsius

The electronic configuration of an elements is 1s²2s²2p⁶3s²3p⁶. How many unpaired electrons are there in the elements

• A. 5
• B. 4
• C. 3
• D. 2

What is the concentration of ions in moles per dm\(^3\) of a solution of pH 4.398?

• A)
  \(4.0 \times 10^{-5}\)
• B)
  \(0.4 \times 10^{-5}\)
• C)
  \(4.0 \times 10^3\)
• D)
  \(0.4 \times 10^{-3}\)

What is the partial pressure of oxygen at s.t.p. in a gaseous mixture containing 100 cm³ of oxygen and 900 cm³ of nitrogen gas?

• A. 1.0 atm
• B. 0.1 atm
• C. 9.0 atm
• D. 0.9 atm

The reactions involving simultaneous oxidation and reduction?

• A. Automatic reactions
• B. Alternate reactions
• C. Reduction agency
• D. Redox reactions

Which of the following is responsible for the conduction of electricity in a gas enclosed in a glass tube containing two electrodes at a reduced pressure and to which a high voltage is applied?

• A) Cations and anions
• B) Cations
• C) Electrons
• D) Cations and electrons

During water treatment for town supply, water is passed through layers of send beds in order to

• A. soften the water
• B. filter the water
• C. decolorize the water
• D. destroy the germs in the water

The knowledge of half-life can be used to

• A) create an element
• B) detect an element
• C) spilt an element
• D) irradiate an element