Question

What is the percent by mass of oxygen in ca(oh)2? [formula mass = 74.1]

Answer 1

16(2)/74.1=.431

.431x100= 43.1%

Answer 2

43.18%

Step-by-step explanation:

To calculate the percentage by mass of oxygen in the compound, multiply the atomic mass of oxygen by two. This is done because the compound contains two moles of oxygen.

16*2=32

32 divided by the formula mass as given in the question multiplied by 100 gives 43.18%