The question ask to predict the effect where as coal can be used to generate hydrogen gas by this endothermic reason and the best answer among your choices based on the element you give is letter C. raising the temperature of the reaction mixture. I hope my answer is correct
The molecular weight of water is <span>18.01528 g/mol.
So in 2.92 grams there are 2.92/</span>18.01528 = 0.1621 mol of particles.
1 mol contains 6,02214 × 10^<span>23 particles by definition.
So the nr of H2O molecules is </span>0.1621 * 6,02214 × 10^23 = 0,9761 × 10^23.
Every molecule has 2 H atoms, so you have to double that.
2* 0,9761 × 10^23 = 1.952 × 10^23.
The pressure of the gas is 1.0 bar.
<em>pV</em> = <em>nRT</em>
<em>T</em> = (0 + 273.15) K = 273.15 K
<em>p</em> = (<em>nRT</em>)/<em>V</em> = (2.0 mol × 0.083 14 bar·L·K⁻¹mol⁻¹ × 273.15 K)/44.8 L = 1.0 bar