Electrolysis is a process that can split water into hydrogen gas and oxygen gas. If 27.1 g of water are split, what is the resulting mole fraction of hydrogen gas? Of oxygen gas? If the gases are in a 12.2 L container at standard temperature, what is the partial pressure of the hydrogen gas? Of oxygen gas?

Explanation:

1. Chemical equation of electrolysis

a) Word equation:

b) Balanced chemical equation:

c)  Mole ratios:

2.  Number of moles of water

i) Formula: Number of moles = mass in grams/molar mass

ii) Molar mass of water: 18.015g/mol

iii) Mass: 27.1 g

iv) Substitute and compute:

3.  Mol fraction of hydrogen gas:

a) Number of moles of hydrogen gas:

Using the theoretical mol ratio of hydrogen to water, 2 moles of water produce 2 moles of hydrogen gas. Then, 1.504 mol of water produce 1.504 mol of hydrogen gas.

b) Number of moles of oxygen gas:

Using the theoretical mol ratio, 2 moles of water produce 1 mole of oxygen gas. The, 1.504 mol of water produce half of 1.504 mol = 0.752 moles of oxygen gas.

c) Mole fraction:

i) Formula:

ii) For hydrogen:

4. Mole fraction of oxygen gas

The mole fraction of all the components of a mixture adds up 1.

The mole fraction of O₂ = 1 - 0.667 = 0.333

5. Partial pressure of the hydrogen gas

i) Calculate the total pressure

Substitute:

ii) Partial pressure

6. Partial pressure  oxygen gas

the density(ratio between mass and volume as m/v) decreases from top to bottom in periodic table group as the size increases and nuclear charge decreases. but in periods density increases from left to right as atom size decreases and nuclear charge increases.