I am not sure what to do here and my books don't help. The brackets have confused me. Please show me the working.What is the relative atomic mass of (the numbers are subscripts):CH3(CH2)7CH3Thanks
The term in bracket means that the term in brackets occurs 7 times in this molecule or in other words CH2 occurs 7 times in this molecule. The atomic mass of carbon is 12g/mol , whilst that of hydrogen is 1g/mol. To calculate atomic mass is (12 + 3*1)+ 7*(12+2*1) + (12 + 3*1) 15 + 7*14 +15 30 +98 128g/mol
