Calculate The Mass of Hydrogen in 150.0 G of Ethene

Ethene (C₂H₄) is a common hydrocarbon with important industrial applications. Calculating the mass of hydrogen in a given mass of ethene is a fundamental chemistry calculation that helps understand the composition of this important compound.

How to calculate the mass of hydrogen in ethene

To determine the mass of hydrogen in a sample of ethene, you'll need to know the molar mass of ethene and the molar mass of hydrogen. Here's the step-by-step process:

Determine the molar mass of ethene (C₂H₄)
Calculate the molar mass of hydrogen (H)
Find the number of hydrogen atoms in ethene
Use the given mass of ethene to calculate the mass of hydrogen

The calculation involves understanding the molecular formula of ethene and applying basic stoichiometry principles.

Formula for hydrogen mass calculation

The mass of hydrogen in a sample of ethene can be calculated using the following formula:

Mass of H = (Mass of C₂H₄ × Number of H atoms × Molar mass of H) / Molar mass of C₂H₄

Where:

Mass of H = mass of hydrogen in the sample
Mass of C₂H₄ = given mass of ethene (150.0 g in this case)
Number of H atoms = 4 (since ethene has the formula C₂H₄)
Molar mass of H = 1.008 g/mol
Molar mass of C₂H₄ = 28.05 g/mol

This formula accounts for the proportion of hydrogen in the ethene molecule relative to the total molar mass of ethene.

Example calculation

Let's walk through the calculation for 150.0 g of ethene:

First, determine the molar mass of ethene: C (12.01 g/mol) × 2 + H (1.008 g/mol) × 4 = 28.05 g/mol
Calculate the number of moles of ethene: 150.0 g ÷ 28.05 g/mol ≈ 5.348 moles
Determine the mass of hydrogen per mole: 1.008 g/mol × 4 = 4.032 g/mol
Calculate the total mass of hydrogen: 5.348 moles × 4.032 g/mol ≈ 21.53 g

Therefore, 150.0 g of ethene contains approximately 21.53 g of hydrogen.

Note: The actual calculation uses the formula directly rather than breaking it into steps, but this example demonstrates the underlying principles.

Interpreting the results

The calculated mass of hydrogen provides several important insights:

It shows the proportion of hydrogen in ethene by mass
It helps understand the composition of the compound
It's useful for stoichiometric calculations in chemical reactions

For example, if you're preparing a solution of ethene, knowing the mass of hydrogen can help determine the amount of hydrogen gas that might be produced in a reaction.

Frequently Asked Questions

What is the formula for ethene?

The molecular formula for ethene is C₂H₄, which means each molecule contains two carbon atoms and four hydrogen atoms.

How do I calculate the molar mass of ethene?

Add the atomic masses of all atoms in the molecule: 2 × carbon (12.01 g/mol) + 4 × hydrogen (1.008 g/mol) = 28.05 g/mol.

Why is the mass of hydrogen different from the number of hydrogen atoms?

The mass depends on both the number of atoms and their individual atomic masses. Hydrogen has a low atomic mass (1.008 g/mol), so even four hydrogen atoms contribute significantly to the total mass.

Can I use this calculation for other hydrocarbons?

Yes, the same principles apply to other hydrocarbons. You would just need to adjust the molecular formula and calculate the appropriate molar masses.