Water is 11.2% by mass hydrogen (H). How many kilograms of water would contain 4.8 g of hydrogen?

1 Answer
Jan 25, 2016

Answer:

We (i) simply determine the atomic quantity of hydrogen; and (ii) give a corresponding atomic quantity of water. We get an answer under 0.045 kg.

Explanation:

If there are 4.8 g of hydrogen in an unspecified quantity of water, there are #(4.8*g)/(1.00794*g*mol^-1)# #=# #4.76# #mol# #H#.

Given the composition of water, #H_2O#, there are thus #2.38# #mol# water.

Thus, mass of water #=# #2.38# #mol# #xx# #18.01# #g*mol^-1xx10^-3*kg*g^-1# #=# #??# #kg#