Molar Mass and Moles Calculation in Chemistry

How to calculate the number of moles of vanillin?

5.7 g vanillin (molar mass = 152.1 g/mol) is dissolved in 140 mL of methyl alcohol (molar mass = 32; density = 9.789 g/ml). What is the number of moles of vanillin?

Answer:

The number of moles of vanillin in 5.7 g is approximately 0.0375 mol.

In order to calculate the number of moles of vanillin, we need to use its molar mass. The molar mass of vanillin is 152.1 g/mol. We can use the formula:

Number of moles (n) = Given mass / Molar mass

Given that the mass of vanillin is 5.7 g and the molar mass is 152.1 g/mol:

n = 5.7 g / 152.1 g/mol = 0.0375 mol

Therefore, the number of moles of vanillin in 5.7 g of vanillin is approximately 0.0375 mol.