Question

Ionisation energy of hydrogen is 13.6ev. How much energy is required to ionise 2gm of hydrogen gas at stp? Bond eneergy of hydrogen is 104 kcal/mol

Answer 1

Answer:

Total energy required to ionize 2 grams of hydrogen gas is 3055.4 kilo Joules.

Explanation:

Moles of hydrogen gas = $\frac{2g}{2 g/mol}=1 mol$

Energy required to break bond of 1 mol of$H_2$ gas:

104 kcal/mol × 1 mol = 104 kcal = 431,392 J

1 kcal = 4184 Joules

Number of hydrogen atom in 1 mol of hydrogen gas:

$1 \times 2\times 6.022\times 10^{23} atoms=1.2044\times 10^{24} atoms$

Ionization energy of 1 hydrogen = 13.6 eV

Energy required to ionize $1.2044\times 10^{24}$ hydrogen atoms:

$1.2044\times 10^{24} \times 13.6 eV=1.638\times 10^{25} eV$

$1 eV=1.60218\times 10^{-19} J$

$1.638\times 10^{25} eV=1.638\times 10^{25}\times 1.60218\times 10^{-19} J$

$=2.624\times 10^{6} J$

Total energy required to ionize 2 grams of hydrogen gas:

$=2.624\times 10^{6} J+431,392 J=3.0554\times 10^6 J=3055.4 kJ$

Answer 2

Answer:

3059.911 kJ

Explanation:

2g of H2 gas = 1 mol of H2 gas.

To convert 1 mol of H2 gas into 2 mol of H, we require 104 Kcal (Bond Energy)

Also, to ionise 2 mol of H, we require 13.6 * 2 * 6.023 * 10^23 eV

Total energy = 104Kcal + 13.6*2*6.023E23 eV

= 3059.911 kJ