15
MCQ (Single Correct Answer)
Which of the following statements indicates that law of multiple proportion is being followed?
A
Sample of carbon dioxide taken from any source will always have carbon and oxygen in the ratio $1: 2$
B
Carbon forms two oxides namely $\mathrm{CO}_2$ and CO , where masses of oxygen which combine with fixed mass of carbon are in the simple ratio $2: 1$
C
When magnesium burns in oxygen, the amount of magnesium taken for the reaction is equal to the amount of magnesium in magnesium oxide formed
D
At constant temperature and pressure 200 mL of hydrogen will combine with 100 mL oxygen to produce 200 mL of water vapour
16
MCQ (Multiple Correct Answer)
One mole of oxygen gas at STP is equal to .........
A
$6.022 \times 10^{23}$ molecules of oxygen
B
$6.022 \times 10^{23}$ atoms of oxygen
C
16 g of oxygen
D
32 g of oxygen
17
MCQ (Multiple Correct Answer)
Sulphuric acid reacts with sodium hydroxide as follows
$$\mathrm{H}_2 \mathrm{SO}_4+2 \mathrm{NaOH} \longrightarrow \mathrm{Na}_2 \mathrm{SO}_4+2 \mathrm{H}_2 \mathrm{O}$$
When 1 L of 0.1 M sulphuric acid solution is allowed to react with 1 L of 0.1 M sodium hydroxide solution, the amount of sodium sulphate formed and its molarity in the solution obtained is
A
$0.1 \mathrm{~mol} \mathrm{~L}^{-1}$
B
7.10 g
C
$0.025 \mathrm{~mol} \mathrm{~L}^{-1}$
D
3.55 g
18
MCQ (Multiple Correct Answer)
Which of the following pairs have the same number of atoms?
A
16 g of $\mathrm{O}_2(\mathrm{~g})$ and 4 g of $\mathrm{H}_2(\mathrm{~g})$
B
16 g of $\mathrm{O}_2$ and 44 g of $\mathrm{CO}_2$
C
28 g of $\mathrm{N}_2$ and 32 g of $\mathrm{O}_2$
D
12 g of $\mathrm{C}(\mathrm{s})$ and 23 g of $\mathrm{Na}(\mathrm{s})$
19
MCQ (Multiple Correct Answer)
Which of the following solutions have the same concentration?
A
20 g of NaOH in 200 mL of solution
B
0.5 mol of KCl in 200 mL of solution
C
40 g of NaOH in 100 mL of solution
D
20 g of KOH in 200 mL of solution