Question

apply: mole calculations with compounds
you might need: calculator, periodic table
a lab requires 1.50 moles of hexane (c₆h₁₄) for use as a solvent.
according to the stockroom bottle, the molar mass of hexane is 86.172 g/mol.
how many grams of hexane are required for the experiment?
express your answer to the nearest whole number.
grams of c₆h₁₄

Explanation:

Step1: Recall the formula for mass from moles and molar mass

The formula that relates moles (\(n\)), mass (\(m\)), and molar mass (\(M\)) is \(m = n\times M\). Here, the number of moles of hexane (\(n\)) is 1.50 moles, and the molar mass (\(M\)) of hexane is 86.172 g/mol.

Step2: Substitute the values into the formula

Substitute \(n = 1.50\space mol\) and \(M = 86.172\space g/mol\) into the formula \(m=n\times M\). So, \(m = 1.50\space mol\times86.172\space g/mol\).

Step3: Calculate the mass

First, multiply 1.50 by 86.172. \(1.50\times86.172 = 129.258\space g\). Then, round this value to the nearest whole number. Rounding 129.258 to the nearest whole number gives 129.

Answer:

129