Question

how many atoms of hydrogen and oxygen are in 0.9 gram of water​

Answer 1

Explanation:Furst we convert 0.09g of water into the number of moles of water. The molar number for H2O is (1+1+16) = 18, so by 0.09/18= 0.005 we know there are 0.005 moles of H2O in 0.09g.

For every water molecule there is one oxygen, so we assume there is the same (0.005) number of moles. Every mole has 6.02 × 10^23 particles, so for 0.005 we multiply (0.005 × 6.02 × 10^23) to get 3.01 × 10^20 atoms of Oxygen.

This can be done identically with hydrogen, with the exception that each H2O molecule has 2 atoms of hydrogen. Therefore the last step is to multiply the number we got for oxygen by two, yielding 6.02 × 10^20 atoms of hydrogen.