How many moles are in 160 g of methane?
1 Answer
Answer:
(or
Explanation:
To convert between moles and grams of any substance, we need to know that's substance's molar mass.
The molar mass of a substance (in this case, methane) is the mass, most typically in grams, of one mole of that substance. [One mole of any substance is Avogadro's number (
Methane has the chemical formula

find how many of each element (
#"C"# and#"H"# ) is present in the compound 
multiply the number of
#"C"# atoms by the relative atomic mass of#"C"# (masses can be found on most periodic tables) 
multiply the number of
#"H"# atoms by the relative atomic mass of#"H"# 
sum the total
First, let's realize that there is

#1# atom of carbon, and 
#4# atoms of hydrogen
per methane molecule. The atomic masses are

#"C"# :#12.01# #"amu"# 
#"H"# :#1.01# #"amu"#
The mass of a substance in atomic mass units (
Therefore, the molar masses of

#"C"# :#12.01# #"g"/"mol"# 
#"H"# :#1.01# #"g"/"mol"#
Now, multiplying each by the number of moles per mole of methane, we have

#"C"# :#(1)(12.01"g"/"mol") = 12.01"g"/"mol"# 
#"H"# : (4)(1.01"g"/"mol") = 4.40"g"/"mol"#
Finally, summing the total, we have
Lastly, using dimensional analysis (which you'll find to use quite often), let's use this and the given mass to find the number of moles of methane:
rounded to
I hope this wasn't too confusing. This really is a straightforward process that you'll use endless times:)