The number of significant figures in the following numbers is:
 

(I).	161 cm
(II).	0.0161
(III).	1.61

1. 3, 3, 3
2. 3, 4, 3
3. 3, 2, 3
4. 3, 4, 4

The mass of CaCO₃ required to react completely with 25 mL of 0.75 M HCl according to the given reaction would be:

CaCO_3(s) + HCl_(aq) ➡ CaCl_2(aq) + CO_2(g) + H₂O_(l) 

1. 0.36 g

2. 0.09 g

3. 0.96 g

4. 0.66 g

One mole of oxygen gas at STP is equal to:

1. (a) and (b)

2. (a) and (c)

3. (a) and (d)

4. (c) and (d)

Sulphuric acid reacts with sodium hydroxide as follows

${\mathrm{H}}_2{\mathrm{SO}}_4+2\mathrm{NaOH}\to {\mathrm{Na}}_2{\mathrm{SO}}_4+2{\mathrm{H}}_2\mathrm{O}$

When 1L 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 are respectively-

1. 0.1 M, 7.10 g

2. 7.10 g, 0.025 M

3. 0.025 M, 3.55 g

4. 3.55 g, 0.25 M

Percentage of C, H & N of a compound is given as follows:
C=40%, H=13.33%, N=46.67%
The empirical formula of the compound will be:

1. $C{H}_{2}N$

2. $C_2{H}_{4}N$

3. $C{H}_{4}N$

4. $C{H}_{3}N$

When 50.0 kg of nitrogen gas (N₂) and 10.0 kg of hydrogen gas (H₂) are combined, what is the quantity of ammonia gas (NH₃) produced?

1. 33.0 ×10³ mol

2. 56.1×10³ g

3. 6.5 ×10³ g

4. None of the above

A solution is prepared by adding 2 g of substance A to 18 g of water. The mass percent of the solute is-

1. 20%

2. 10%

3. 15%

4. 18%

The NaNO₃ weighed out to make 50 mL of an aqueous solution containing 70.0 mg Na⁺ per mL is- 

(Rounded off to the nearest integer) [Given: Atomic weight in g mol^–1 – Na: 23; N: 14; O: 16]

1. 13 g

2. 26 g

3. 18 g

4. 22 g

An aqueous solution of urea containing 18 g of urea in 1500 cm³ of the solution has a density of 1.052 g/cm³. If the molecular weight of urea is 60, then the molality of the solution is-
1. 0.2
2. 0.192
3. 0.064
4. 1.2