Chromatography is used to separate components of mixtures which differ in their rates of?

A. diffusion

B. migration

C. reaction

D. sedimentaion

Which of the following is a example of a chemical change?

A. Dissoultion of salt in water

B. Rusting of iron

C. Melting of ice

D. Separating a mixture by distillation

The number of hydrogen ions in 4.9 g of tetraoxosulphate (IV) acid is?

(S = 32, O =16, H = 1, Na = 6.02 x 10₂₃

A. 3.01 x 10₂₂

B. 6.02 x 10₂₂

C. 3.01 x 10₂₃

D. 6.01 x 10₂₃

What volume of oxygen will remain after reacting 8cm³ of hydrogen with 20cm³ of oxygen?

A. 10 cm³

B. 12 cm³

C. 14 cm³

D. 16 cm³

A gas sample with an initial volume of 3.25 dm³ is heated and allowed to expand to 9.75 dm³ at constant pressure. What is the ratio of the final absolute temperature to the initial absolute temperature?

A. 3:1

B. 5:2

C. 5:4

D. 8:3

Two cylinders A and B each contains 30 cm³ of
oxygen and nitrogen respectively at the same temperature and pressure. If there are 5.0 moles of nitrogen, then the mass of oxygen is?

A. 3.2 g

B. 6.4 g

C. 80.0 g

D. 160.0 g

A liquid begins to boil when?

A. its vapour pressure is equal to the vapour pressure of its solid at the given temperature

B. molecules start escaping from its surface

C. its vapour pressure equals the atmosphere pressure

D. its volume is sightly increased

A particle that contains 8 proton, 9 neutrons and 7 electrons could be written as?

A. O

B. O⁺

C. O⁺

D. O^-

In the oil drop experiment, Millikan determined the?

A. charge to mass ratio of the electron

B. mass of the electron

C. charge of the electron

D. mass of the proton