[mnuslt]

I know that there is a simple anwers to this question but I guess because it is final examine time I am brain dead.
How many grams of hydrogen are in 46g of CH4O?
 I have tried to work this problem out using the % composion method, using the avogadro's #, stoichiometry but I am at a lost please help !!!!!!!!!

[Mitch]

First convert it to moles.

[Dude]

The easiest way is to calculate the % of hydrogen in the molecule and then multiply it by the total # of grams:
1  C  x 12 g/mol
4  H  x  1 g/mol
1  O  x  16 g/mol
= 32 g/mol (methanol would appear to be the only choice)

4 g H / 32 g total  = 12.5 % H / mole
46 g x .125 = 5.75 g hydrogen

[mnuslt]

Thank you Dude that really help me to understand, I work it on some other test question that I missed and it worked.