water is 11.2% by mass hydrogen. How many milligrams of water would contain 5g of hydrogen?

Answer 1

Let us check % of hydrogen in water by weight:
H2O = molecular weight = (1 x2) + (16 x 1) = 18 approx.
Where H = 1 atomic weight & O = 16 atomic weight.
Thus 18 gm of water will contain 2 gm of H or 1/9 = 11.2% OK (approximate).

One gm of water will contain 0.112 gm of hydrogen.
For 5 gm of hydrogen, we need 5/0.112 = 44.643 gm of water

Which is equal to 44643 milligrams of water.

Answer 2

1 gram of water is 11.2 mg. 5000mg/11.2mg = 446.43. So you would need 446.43 grams of water to have 5 grams of hydrogen.

Answer 3

well lets use "x" as amount of water so we are looking at this.

x*11.2%=5g

so now you have to devide the 11.2% out so you end up at.

x=5g/11.2%