Question

which of the following contains the largest number of atoms?A. 11g of co2 B. 4g of h2

Answer 1

Answer:- B. 4g of $H_2$

Explanation: According to avogadro's law, 1 mole of every substance occupies 22.4 Liters at STP and contains avogadro's number $6.023\times 10^{23}$ of particles.

To calculate the moles, we use the equation:

$\text{Number of moles}=\frac{\text{Given mass}}{\text {Molar mass}}$

1. $\text{Number of moles of carbon dioxide}}=\frac{11g}{44g/mol}=0.25moles$  

Now 1 mole of $CO_2$ molecule contains = $3\times 6.023\times 10^{23}=18.06\times 10^{23}$ atoms

0.25 mole of $CO_2$ molecule contains = $\frac{18.06\times 10^{23}}{1}\times 0.25=4.5\times 10^{23}$ atoms

2.  $\text{Number of moles of hydrogen}}=\frac{4g}{2g/mol}=2moles$  

Now 1 mole of $H_2$ molecule contains = $6.023\times 10^{23}$ atoms

2 moles of $H_2$ molecule contains = $\frac{6.023\times 10^{23}}{1}\times 2=12.05\times 10^{23}$ atoms

Answer 2

4g of h2 contains the largest number of atom