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When calculating the molar mass of a compound, it is essential to know the elements present and their individual atomic masses. The molar mass is the sum of the masses of all atoms in the compound in grams per mole. Here's the simplified procedure:

- Identify each element in the compound and note the number of moles of each element.
- Multiply the atomic mass of each element by the number of moles in the compound.
- Add all the results together to get the total molar mass.

For example, in compound (a) \(\text{C}_4\text{H}_{10}\text{O}\), the contribution of carbon is considerable. To find the molar mass, compute \(4 \times 12.01\) for carbon, \(10 \times 1.008\) for hydrogen, and \(16.00\) for oxygen. Adding these gives the molar mass: \(74.12 \, \text{g/mol}\).

Understanding molar mass helps us determine how much of a compound's total weight is made up by a particular element, such as carbon.

Percent composition is vital in chemistry to understand what fraction of a compound's total mass is due to each element. Calculating percent composition involves dividing the mass of each type of atom by the molar mass of the compound and multiplying by 100.

This provides the percentage of the compound by mass that comes from each element. For compound (a) \(\text{C}_4\text{H}_{10}\text{O}\), the percent by mass of carbon is found using:

- Calculate the total mass of carbon atoms in the compound: \(4 \times 12.01\)
- Divide this by the compound's total molar mass \(74.12\)
- Multiply by 100 to get \(64.8\%\)

Thus, 64.8% of the mass of \(\text{C}_4\text{H}_{10}\text{O}\) is due to carbon. This knowledge aids in analyzing the compound's properties and its reactions with other substances.

Stoichiometry involves calculations that relate the masses and percent compositions of reactants and products in chemical reactions. It allows us to predict how substances interact and transform during reactions.

To find the mass of carbon in a specific amount of compound, multiply the mass of the compound by the percent composition of carbon. This converts the percentage into a tangible mass.

- Using compound (a), for instance, the percent mass of carbon was previously calculated as \(64.8\%\).
- If you're given \(1.80\, \text{g}\) of \(\text{C}_4\text{H}_{10}\text{O}\), multiply \(1.80\, \text{g}\) by \(\frac{64.8}{100}\) to find \(1.17\, \text{g of C}\).

Understanding stoichiometry is critical for determining how much of each element is involved in reactions, particularly when calculating yields and assessing the efficiency of chemical processes.