(a) Define the term ionization energy.           (1mk)

(b) State and explain a factor that determine the value of ionization energy of a given element.    (2mk)

State two factors that accelerate rusting                  (2mks)

280cm³ of nitrogen gas diffuse through a porous plug in 70 seconds. How long will it take 400cm³ of carbon (IV) oxide gas to diffuse through the same porous plug?  (C = 12 , 0 = 16 , N = 7)          (3mks)

The set-up below can be used to study the reaction of magnesium and steam.

(a) Name gas P.              (1mk)

(b) Explain the observation made when copper is used instead of magnesium in the set-up above.    (1mk)

(c) Write the equation for the reaction between magnesium and steam.     (1mk)

(a) Using electrons in the outermost energy level , draw the dot(.) and cross (X) diagrams to represent bonding in:

i) C₂H₆                               (1mk)

ii) Magnesium nitride              (1mk)

(b) The formula of a complex ion is [Cu(NH₃)₄]²⁺ Name the type of bond that is likely to exist between copper and ammonia in the complex.          (1mk)

(a) A few drops of freshly prepared Iron (II) Sulphate solution were added to Potassium nitrate solution in a test-tube. Concentrated sulphuric acid was then carefully added to the mixture. State the observations that were made.         (1mk)

(b) Write an equation for the reaction that occurs when solid potassium nitrate is strongly heated.    (1mk)

(c) What is the role of the test shown in (a) above.        (1mk)

The following diagrams show the structure of two allotropes of carbon. Study them and answer the questions that follow.

a) Name the allotropes  A and B.           (1mk)

A……………………………………..

B……………………………………..

b) Give one use of A.                                      (1/2mk)

c) Which allotrope conducts electricity? Explain.          (1¹/₂mk)

The grid below is part of the periodic table. Study it and answer the questions that follow. The letters are not actual symbols of elements.

a) What is the name given to the chemical family of element C?       (1mk)

b) Would element B reacts with J? Explain.        (1mk)

c) Compare the melting points of B and M.         (1mk)

Samples of urine from three participants U , V and W at an international sport meeting were spotted onto chromatography paper alongside two from illegal drugs T1 and T2. A chromatogram was run using methanol. The figure below shows the chromatogram.

(a) Identify the athlete who had used an illegal drug.           (1mk)

(b) Which drug is more soluble in methanol?          (1mk)

(c) Identify a mistake made on the chromatogram.        (1mk)

The scheme below shows the energy changes that are involved between ice , water and steam. Study it and answer the questions that follow.

(a) What name is given to the process represented by energy change ?       (1mk)

(b) What is the sign of ? Give a reason          (2mks)