43
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
44
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
45
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
46
Chromatography is used to separate components of mixtures which differ in their rates of?
- A. diffusion
- B. migration
- C. reaction
- D. sedimentaion