What is the molar mass of aspirin, [tex]$C _9 H _8 O _4$[/tex]?
Answer (2)
Determine the atomic masses of Carbon, Hydrogen, and Oxygen.
Multiply each atomic mass by the number of corresponding atoms in the aspirin molecule: 9 C , 8 H , and 4 O .
Sum the results to find the molar mass of aspirin: ( 9 × 12.01 ) + ( 8 × 1.008 ) + ( 4 × 16.00 ) = 180.154 g / m o l .
The molar mass of aspirin is approximately 180.17 g / m o l .
Explanation
Understanding the Problem We want to find the molar mass of aspirin, which has the chemical formula C 9 H 8 O 4 . To do this, we need to multiply the number of atoms of each element by its atomic mass and then add these values together.
Identifying Atomic Masses The atomic masses of the elements in aspirin are:
Carbon (C): 12.01 g/mol
Hydrogen (H): 1.008 g/mol
Oxygen (O): 16.00 g/mol
Calculating Element Contributions Now, we multiply the number of atoms of each element in aspirin by its atomic mass:
Carbon: 9 a t o m s × 12.01 g / m o l = 108.09 g / m o l
Hydrogen: 8 a t o m s × 1.008 g / m o l = 8.064 g / m o l
Oxygen: 4 a t o m s × 16.00 g / m o l = 64.00 g / m o l
Summing the Contributions Finally, we add these values together to get the molar mass of aspirin: 108.09 g / m o l + 8.064 g / m o l + 64.00 g / m o l = 180.154 g / m o l
Final Answer The molar mass of aspirin ( C 9 H 8 O 4 ) is approximately 180.154 g / m o l . Among the given options, the closest value is 180.17 g / m o l .
Examples
Understanding molar mass is crucial in chemistry for calculating the amounts of substances needed in reactions. For instance, if you're synthesizing aspirin in a lab, knowing its molar mass allows you to accurately measure the reactants required to produce a specific amount of aspirin. This ensures the reaction proceeds efficiently and yields the desired product without wasting materials. Molar mass calculations are also essential in pharmaceutical formulations, environmental studies, and material science, making it a fundamental concept in various scientific fields.
The molar mass of aspirin ( C 9 H 8 O 4 ) is calculated by adding the contributions from Carbon, Hydrogen, and Oxygen. The total molar mass is approximately 180.17 g/mol . This calculation is essential for understanding the quantity of substances in chemical reactions.
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