Question

(A) List the uses of the following apparatus: [3 Marks]
i) Round bottom flask
ii) Reagent bottle
iii) Pipette

(B) Name the chemicals which help in increasing food production. [4 Marks]

(C) Why is it necessary to take precautions while working in a chemical laboratory? [3 Marks]

Answer 1

(A) i) A round bottom flask is used for heating sufficient quantities of liquids. It cannot be used to store liquids as it has a round bottom, and hence cannot be placed on flat surfaces. [1 Mark]
ii) A reagent bottle is a large container used to store chemicals. To store chemicals sensitive to light, a dark-coloured reagent bottle must be used. [1 Mark]
iii) A pipette is used to accurately measure and dispense fixed amounts of liquids. For example, a 5 ml pipette can measure only 5 ml of a liquid. [1 Mark]

(B) Chemistry has helped in increasing food production by providing chemicals. Few chemicals are discussed below:
$\bullet$ Fertilisers: These chemicals provide essential nutrients to the crops and increase their yield. Examples: urea, sodium nitrate, ammonium phosphate, potash, calcium nitrate, etc. (1 mark)
$\bullet$ Pesticides: These chemicals are used to kill pests that affect the production of crops. Examples: aldrin, parathion, malathion, etc. (1 mark)
$\bullet$ Fungicides: These are the chemicals that protect the crops from fungi. Examples: sulphur and Bordeaux mixture ( 1 mark)
$\bullet$ Insecticides: These chemicals are used to kill insects. Examples: D.D.T., B.H.C., etc. (1 mark)

(C) A laboratory poses potential risks due to exposure to corrosive and toxic materials, flammable solvents, high-pressure gases, explosive chemicals and dangerous microbes. [2 Marks]
Following the safety precautions will help us avoid these kinds of accidents while working in a chemical laboratory. [1 Mark]