Question

what is the mass of 6.80 moles h₂o? molar mass h₂o = 18.02 g/mol ? g h₂o

Explanation:

Step1: Recall the formula for mass calculation

The formula is \(m = n\times M\), where \(m\) is mass, \(n\) is the number of moles, and \(M\) is molar mass.

Step2: Substitute the given values

Given \(n = 6.80\space mol\) and \(M=18.02\space g/mol\).
So, \(m=6.80\space mol\times18.02\space g/mol\)
$$m = 6.80\times18.02\space g$$
$$m=(7 - 0.2)\times18.02\space g=(7\times18.02-0.2\times18.02)\space g$$
$$m = 126.14- 3.604\space g$$
$$m=122.536\space g$$

Answer:

\(122.54\space g\) (rounded to four significant figures as the least number of significant figures in the given values \(6.80\) (three) and \(18.02\) (four) is three, but \(6.80\) has a trailing zero which is significant, so we can present it as \(122.54\) considering the calculation result \(122.536\approx122.54\) when rounded to four significant figures)