16 g of oxygen has the same number of molecules as in:

(a) 16 g of CO

(b) 28 g of N₂

(c) 14 g of N₂

(d) 1.0 g of H₂

1. (a), (b)

2. (b), (c)

3. (c), (d)

4. (b), (d)

Unitless terms among the following are:

The incorrect statements regarding 1 mole of dioxygen gas at STP from the above four statements are: 

The numbers 234,000 and 6.0012 can be represented in scientific notation as:

1. $2.34\times {10}^{-9} \mathrm{and} 6\times {10}^3$

2. 0.234 $\times {10}^{-6}$ and $60012\times {10}^{-9}$

3. $2.34\times {10}^{-9} \mathrm{and}$ $6.0012\times {10}^{-9}$

4. 2.34$\times {10}^5$ and 6.0012$\times {10}^0$

0.50 mol  Na₂CO₃ and 0.50 M Na₂CO₃ are different because:

Round up the following number into three significant figures: 
i. 10.4107  ii. 0.04597 respectively  are 

The following data was obtained when dinitrogen and dioxygen react together to form different compounds:

The law of chemical combination applicable to the above experimental data is:
1. Law of reciprocal proportions
2. Law of multiple proportions
3. Law of constant composition
4. None of the above.

An organic compound contains 80 % (by wt.) carbon and the remaining percentage of hydrogen. The empirical formula of this compound is:
[Atomic wt. of C is 12, H is 1] 
1. CH₃
2. CH₄
3. CH
4. CH₂