What is the molecular weight of propane (C3H8)?
Molecular Weight:
The molecular weight or molar mass can be calculated based on the chemical formula of the compound which is expressed in terms of grams per mole (grams/mole). For the problem, the given compound is propane and the correct chemical formula was also provided. Aside from the chemical formula, the molar mass of each element involved in the compound must also be provided to determine the molecular weight (or molar mass).
The Correct Answer and Explanation is :
The molecular weight (or molar mass) of propane (C₃H₈) can be calculated using the atomic weights of its constituent elements: carbon (C) and hydrogen (H). The atomic weight of carbon is approximately 12.01 grams per mole (g/mol), and the atomic weight of hydrogen is about 1.008 g/mol.
Propane consists of three carbon atoms and eight hydrogen atoms, as indicated by its chemical formula (C₃H₈). To calculate the molecular weight, we can follow these steps:
- Calculate the total weight from carbon:
- There are 3 carbon atoms in propane:
[
3 \, \text{C} \times 12.01 \, \text{g/mol} = 36.03 \, \text{g/mol}
]
- Calculate the total weight from hydrogen:
- There are 8 hydrogen atoms in propane:
[
8 \, \text{H} \times 1.008 \, \text{g/mol} = 8.064 \, \text{g/mol}
]
- Add the two contributions together to find the total molecular weight of propane:
[
\text{Molecular Weight of C}_3\text{H}_8 = 36.03 \, \text{g/mol} + 8.064 \, \text{g/mol} = 44.094 \, \text{g/mol}
]
Thus, the molecular weight of propane is approximately 44.10 g/mol when rounded to two decimal places.
Explanation:
Molecular weight is an essential concept in chemistry, as it helps to determine the amount of a substance in a given volume, crucial for stoichiometric calculations in chemical reactions. Knowing the molecular weight allows chemists to convert between grams and moles, enabling precise formulation of reactions. For instance, if one needs to produce a specific amount of propane in a reaction, understanding its molecular weight aids in calculating the required quantities of reactants. Moreover, the properties of propane, such as its energy content and reactivity, can also be correlated with its molecular weight, making it a fundamental aspect in both academic research and practical applications, such as in fuels and refrigeration.