What is the mass of 0.5 moles of #"CO"_2# ?

2 Answers
Jun 26, 2018

#22# grams.

Explanation:

We use the following formula

#n("moles") = (m("mass"))/(M("molar mass"))#

Rearranging this equation, we find that

#m = n * M#

We are given the moles #(0.5)#, so we need to find the molar mass. I'm assuming you are given a table of molar values of elements such as carbon is #"12 g/mol"#..

So to find moles, we add all the molar values together

#M("CO"_2) = M("C") + 2*M("O")#

#M("CO"_2) = (12 + 2*16) \ "g/mol"#

#M("CO"_2) = 44 \ "g/mol"#

Therefore, we can then use the above-rearranged equation to find #m#:

#m = "0.5 moles" * "44 g/mol"#

#m = "22 g"#

Jun 27, 2018

#22# grams

Explanation:

To find the mass of a certain number of moles of a substance, we multiply the number of moles of the substance by its molar mass.

Carbon dioxide #(CO_2)# has a molar mass of #44.01 \ "g/mol"#. Here, there are #0.5 \ "mol"# of the molecule. So, the mass of this sample is:

#m=(44.01 \ "g")/(color(red)cancelcolor(black)"mol")*0.5color(red)cancelcolor(black)"mol"#

#~~22 \ "g"#