Chemistry

Question 1

1In paper chromatography, a spot moved 3.0 cm while the solvent moved 6.0 cm. Its Rf value is ___.

Medium

Your answer (fill in the blank)

Question 2

2The best method to separate salt from salt solution is

Easy

A. filtration B. decantation C. sublimation D. evaporation

Question 3

3A substance labelled with a skull and crossbones symbol is

Easy

A. corrosive B. radioactive C. toxic D. flammable

Question 4

4Safety goggles should be worn when heating chemicals.

Easy

A. True B. False

Question 5

5When diluting a concentrated acid, you should

Medium

A. add the acid slowly to water B. shake the acid in a closed bottle C. add water quickly to the acid D. heat the acid first

Question 6

6The piece of apparatus used to heat a solid strongly to constant mass is a

Easy

A. burette B. crucible C. pipette D. measuring cylinder

Question 7

7Iron filings can be removed from sulphur powder using

Easy

A. water B. a separating funnel C. a magnet D. chromatography

Question 8

8Centrifugation separates

Medium

A. metals from ores B. two gases C. fine solid particles suspended in a liquid by spinning D. dissolved salts

Question 9

9You should taste chemicals to identify them in the laboratory.

Easy

A. True B. False

Question 10

10The solid left on the filter paper after filtration is the ___.

Easy

Your answer (fill in the blank)