ROOTS IVY INTERNATIONAL SCHOOL, FAISALABAD CAMPUSIG-I Chemistry Retake Sessional paper

Name:______________________Marks obtained:

Q.1 Choose the best answer.[5]

1. Which piece of apparatus would be most suitable for placing 24.7 cm3 of a liquid into a beaker?

A a buretteB a measuring cylinder C a pipetteD a syringe

2. A liquid ester used to flavour food is believed to be impure. What would be the best way of testing its purity?

A filter itB measure its boiling point C use paper chromatographyD evaporate it to dryness

3 Which substance is likely to be a pure compound?

A a yellow liquid that boils at exactly 124oC B a white powder that dissolves in water C a colourless liquid which gives two fractions when distilled D green crystals that melt over the range 68oC to 72oC

4.Compound Q melts at 78oC and boils at 124oC and is not soluble in water. Which apparatus can be used to obtain pure Q from a mixture of Q and water.

A B C D

5.Substance S contains one of the three substances X, Y or Z. Two chromatograms of the four substances, using different solvents, are shown in the diagrams.

Solvent I Solvent II solvent front solvent front

start line start line

S X Y Z S X Y Z

What does substance S contain?

A X only B Z only C X and Z D Y and Z

Q.2 Several pieces of laboratory apparatus are shown in the diagram

E F A B D

G C

I H

(a) Give the letter and name of the piece of apparatus best used for the following (give a different letter for each answer):

(i) measuring a fixed volume of 25cm3 ......................................................................................................................... (ii) collecting and measuring the volume of about 40 cm3 of a gas

.......................................................................................................................... (iii) delivering exactly 20.8 cm3 of a liquid to a container, drop-by-drop

........................................................................................................................... (iv) measuring a temperature of a solution

...........................................................................................................................(vi) separating a mixture of sand and water

............................................................................................................................[10]

Q.3 Calculate moles of [6]

i) 51g of ammonia NH3

ii) 20g of sodium hydroxide NaOH

iii) 9.125 g of HCl

Q.4Name a suitable separation method that can be used to [4]

(a) get petrol and diesel from petroleum ___________

(b) get iodine from a mixture of iodine and sodium chloride __________

(d) obtain pure water from sea water ___________

(e) obtain salt from sea water ___________