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Briefly explain how you would obtain pure sample of lead (ii) chloride from a mixture of lead (ii) chloride and silver chloride (3mks)

Study the table below and answer the questions that follow

Bond type

Bond energy
KJ/mol

 C-C

 346

 C=C

 610

 C-H

 413

 C-Br

 280

 Br-Br

193

 

(a) Calculate the enthalpy of the following reaction. (2mks)
C2H4(g) + Br2(g)  C2H4Br2(g)

 

 

 

 

(b) Name the type of reaction that took place in a) above (1mk)

Study the standard electrode potentials for the half-cells give below and answer the questions that follows ( the letters do not represent the actual symbols of the elements)

 

E Volts

N+(aq) +   N(s)

 -2.92

J+(aq) +   J(s)

 +0.52

K+(aq) +   K(s)

 0.00

G+(aq) +   G(s)

 +1.36

M2+(aq) + 2  M(s)

 -0.44

(a) Identify

i. The strongest reducing agent  (½ mks)

 

 

ii. The strongest oxidizing agent  (½mks)

 

 

(b) Calculate the e.m.f of the cell (2mks)
N(s)/N+(aq) // G+(aq)/G(s)

Name the process which takes place when

(a) Solid carbon (iv) oxide changes directly into gas (1mk)

 

 

(b) Butanol reacts with hexanoic acid in the presence of Sulphuric (iv) acid. (1mk)

Element T consists of two isotopes 62T and 64T in the ratio 7:3 respectively. Calculate the Relative atomic mass of element T (3mks)

(a) State Charles’ law  (1mk)

 

 

 

(b) The volume o f a sample of nitrogen gas at temperature of 298k and 600mmHg pressure was 0.048m3, calculate the temperature at which the volume of the gas would be 0.032m3 if pressure remains the same.  (2mks)

The diagram below show the set up that was used to prepare and collect Sulphur (iv) oxide gas.

(a) Identify the solid P      (1mk)  

 

 

(b)

i. Why is it possible to collect Sulphur (iv) oxide as shown?   (1mk)

 

 

ii. What happened to the red flower?       (1mk)

The table below shows the atomic number of elements M, P, Q and R.

Element

 P

 Q

 R

 S

Atomic No

13 

7 

12 

13 

Mass No

 26

 15

 24

 27

 

(a) Which two letters represent the same element? Give reasons (1mk)

 

 

 

(b) Give the number of neutrons of an atom of element Q (1mk)

When hydrogen Sulphide gas was bubbled into an aqueous solution of iron (iii) chloride, a yellow precipitate was deposited.

(a) State another observation that would be made (1mk)

 

 

(b) Write an equation of the reaction that took place. (1mk)

A certain mass of marble chips reacted with excess dilute hydrochloric acid at 250c. The volume of carbon (iv) oxide gas liberated was measured after 30 seconds. The results were presented as shown in the graph below.

(a) Name one piece of apparatus that may have been used to measure the volume of the gas liberated. (1mk)

 

                                          

(b) On the same axis sketch the curve that would be obtained if the experiment was repeated using powdered calcium carbonate. (1mk)