The diagram below shows a Bunsen burner when in use

(a) Name the regions labelled B and C   (1mk)
B

....................................................
C

.....................................................

(b) What is the function of the part labelled A?   (1mk)

NO₂ and N₂O₄ gases exist in equilibrium at 20⁰C

State and explain the observation that would be made when

(a) A syringe containing the mixture 20⁰C is heated to 40⁰C  (1mk)

(b) The gaseous mixture in a syringe is compressed.  (1mk)

The equations below shows the molar enthalpies of combustion of carbon, hydrogen and methane.
C_(s) + O_2(g)    CO_2(g)         Hc = -393 KJmol^-1
H_2(g) + ½ O_2(g)     H₂O_(l)    Hc = -285 KJmol^-1
CH_4(g) + O_2(g)     CO_2(g)    Hc = -890KJmol^-1
Use the energy cycle diagram to calculate the heat of formation of methane   (3mks)

Study the flow chart below and answer the questions that follows:

(a) Name the reagent Z and Y

   i.  Z (1mk)

   ii.  Y (1mk)

(b) Write the formula of the complex ions presented in the deep blue solution (1mk)

Starting with lead oxide, nitric acid, sodium sulphate, water and all necessary apparatus, describe how you would prepare a dry sample of lead (II) sulphate       (3mks)

The diagram below shows a set up that was used to prepare and collect a sample of nitric acid.

(a) Give a reason why it is possible to separate nitric acid from Sulphuric acid in the set up.  (1mk)

(b) Name another substance that can be used instead of potassium nitrate.  (1mk)

In an experiment to determine the solubility of potassium nitrate at 30⁰C, a saturated solution was heated in an evaporating dish until there was no further change in mass. The following data was obtained.

Mass of dish + solution = 128.9 g

Mass of dish + dry salt = 103.9 g

Mass of empty dish = 94.3 g

Determine the solubility of potassium nitrate at 30⁰C. (3mks)

The graph below shows the changes which takes place when a solid is heated.

(a) What happened to the molecules between W and X?    (1mk)

(b) What is the significance of temperatures T₁ and T₂    (1mk)

(c) Explain why the temperature does not rise between X and Y    (1mk)

Equal volumes of 2M monobasic acids R and S were each reacted with excess magnesium ribbon. The table below shows the volume of the gas produced after one minutes

(a) Write the ionic equation for reaction which took place  (1mk)

(b) Explain the difference in the volumes of the gas produced  (2mks)

When hydrated sample of iron (II) Sulphate FeSO₄. nH₂O was heated until there was no further change in mass, the following data was recorded.
Mass of evaporating dish = 78.94g
Mass of evaporating dish + hydrated salt = 84.14g
Mass of evaporating dish + residue = 81.78g
Determine the empirical formula of the hydrated salt
(Relative formula Mass of FeSO₄ = 152, H₂O = 18)              (3mks)