How much positive and negative charge is present in 1gm of water? How many electrons are present in it? Given, molecular mass of water is 18.0 g.

Explanation

Molecular mass of water is 18.0 gm, that means the number of molecules in 18.0 gm of water is `6.02xx10^(23)`.
`:.` Number of molecules in 1gm of water = `6.02xx10^(23)//18`. One molecule of water (`H_2O`) = contains two hydrogen atoms and one oxygen atom. Thus the number of electrons in `H_2O` is sum of the number of electrons in `H_2` and oxygen. There are 2 electrons in `H_2` and 8 electrons oxygen.
`:.` Number of electrons in `H_2O` = 2+8 = 10.
Total number of protons / electrons in 1.0 gm of water = `(6.02xx10^(23))/(18) xx10=3.34xx10^(23)`
Total positive charge = `3.34xx10^(23) xx" charge on a proton"`
`= 3.34xx10^(23)xx1.6xx10^(-19) C= 5.35xx10^4 C`
This positive charge is balanced by equal amount of negative charge so that the water molecule is electrically neutral.