The maximum number of atoms is present in which of the following -

1. 1 g of Mg_(s)  

2. 1 g of O_{2 (g)}

3. 1 g of Li_(s)    

4. 1 g of Ag_(s)   

 The empirical formula of an oxide of iron, which has 69.9% iron and 30.1% oxygen by mass is -

1. FeO

2. Fe₂O₃

3. Fe₃O₄

4. Fe₃O₂

If the density of the solution is 3.12 g ml^-1, then what will be the mass of the 1.5 ml solution in two significant figures?

Match the following physical quantities with units.

Codes:

The density of a 2 M aqueous solution of NaOH is 1.28 g/$c{m}^3$. The molality of the solution is: 
[molecular mass of NaOH = 40 $gmo{l}^{-1}$]

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. $C{H}_{3}N$

The number of significant figures in the following numbers is:
 

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:

Choose the correct answer from the option given below: 

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