What is the molar mass of CH3CH3? Average atomic masses of C and H are 12.00 g/mol and 1.008 g/mol respectively.
The correct answer and explanation is:
Sure! Let’s calculate the molar mass of CH3CH3 (which is ethane).
Step 1: Identify the atoms and their quantities in the molecule
- CH3CH3 means there are:
- 2 carbon (C) atoms
- 6 hydrogen (H) atoms (3 hydrogens per each carbon)
Step 2: Use the given average atomic masses
- Carbon (C) = 12.00 g/mol
- Hydrogen (H) = 1.008 g/mol
Step 3: Calculate the total molar mass
Molar mass=(number of C atoms×atomic mass of C)+(number of H atoms×atomic mass of H)\text{Molar mass} = (\text{number of C atoms} \times \text{atomic mass of C}) + (\text{number of H atoms} \times \text{atomic mass of H}) =(2×12.00 g/mol)+(6×1.008 g/mol)= (2 \times 12.00 \, \text{g/mol}) + (6 \times 1.008 \, \text{g/mol}) =24.00 g/mol+6.048 g/mol=30.048 g/mol= 24.00 \, \text{g/mol} + 6.048 \, \text{g/mol} = 30.048 \, \text{g/mol}
Final answer:
The molar mass of CH3CH3 (ethane) is 30.048 g/mol.
Explanation:
Molar mass is the mass of one mole of a substance, usually expressed in grams per mole (g/mol). To find the molar mass of a compound, you add up the atomic masses of all the atoms present in one molecule of the compound.
In ethane (CH3CH3), the formula tells us it has two carbons and six hydrogens. Since the atomic masses of carbon and hydrogen are known (12.00 g/mol for carbon and 1.008 g/mol for hydrogen), the total molar mass is found by multiplying each atom’s mass by its count, then adding those totals together.
This calculation is important because molar mass allows chemists to convert between grams of a substance and the number of moles, which is essential for stoichiometric calculations in chemical reactions. Knowing molar masses helps you understand how much of each reactant or product is involved in a reaction and allows you to measure chemicals accurately.
For example, if you needed 1 mole of ethane for a reaction, you would weigh out approximately 30.048 grams. This concept is foundational in chemistry and essential for laboratory work, industrial processes, and understanding molecular properties.