A sample of C25H52 weighs 29.29 g. Its molar mass is 352.77g/mol. How many grams of carbon are in this sample?

Any help is much appreciated!

2 Answers
Jan 24, 2017

Answer:

#24.93g#, rounded to two decimal places.

Explanation:

Given is sample of #"C"_25"H"_52#

We see that #1" g mol"# of sample has #25# carbon atoms

Taking Average atomic mass of carbon #"C"=12.011" amu"#, we obtain gram molecular weight of carbon in 1 mol of sample#=25xx12.011#
#=300.275#
Setting up the equation

#352.77g# of sample has carbon#=300.275g#
#1g# of sample has carbon#=300.275/352.77g#
#29.29 g# of sample has carbon#=300.275/352.77xx29.29#
#=24.93g#, rounded to two decimal places.

Jan 24, 2017

Answer:

Approx. #25*g#

Explanation:

#%"by mass of carbon with respect to 1 mole of "C_25H_52# #=# #(25xx12.011*g*mol^-1)/(352.77*g*mol^-1)xx100%=85.12%#

And thus, in a #29.29*g# mass, #%C=29.29*gxx85.12%=??#