General Practicals

Question 1

Safety precaution for irritants

Answer 1

Wear goggles

Question 2

Safety precaution for corrosive

Answer 2

Wear goggles

Question 3

Safety precaution for flammable

Answer 3

Keep away from naked flames

Question 4

Safety precaution for toxic

Answer 4

Wear gloves, avoid skin contact, wash hands after use

Question 5

Safety precaution for oxidising

Answer 5

Keep away from flammable/ easily oxidised materials

Question 6

When heating in a crucible why is a lid used

Answer 6

Improves accuracy as it prevents the loss of solid from crucible.
Should be loose fitting to allow gas to escape

Question 7

Why should large amount of solid not be used when heating in a crucible

Answer 7

Decomposition is likely to be incomplete

Question 8

Why should very small amounts of solid not be used when heating in a crucible

Answer 8

Percentage uncertainties in weighing will be too high

Question 9

Errors in using a gas syringe

Answer 9

Gas escapes before the bung is inserted
The syringe sticks
Some gases like CO2 and SO2 are soluble in water so the true amount of gas is not measured