Question

Calculate the number of hydrogen atoms per cubic centimeter for the following matters: (a) fresh water, (b) oil (C,H , 0.8 g/cm3), and (c) methane (CH4, 0.01 g/cm3).

Answer 1

a) 6,69x10²² atoms H/cm³

b) 6,87x10²² atoms H/n·cm³

c) 1,50x10²¹ atoms H/cm³

Step-by-step explanation:

You can obtain the number of hydrogen atoms per cubic centimeter using density, molar mass and Avogadro's number, thus:

a)
`(1g)/(1cm^3)`×
`(1mole H_(2)O)/(18,01g)`×
`(2molH)/(1molH_(2)O)`×
`(6,022x10^(23)atoms)/(1molH)` = 6,69x10²² atoms H/cm³

b) As oil formula is
`C_(n)H_(2n)`

`(0,8g)/(1cm^3)`×
`(1mole C_(n)H_(2n))/(12ng+1*2,02ng)`×
`(2molH)/(1molC_(2)O)`×
`(6,022x10^(23)atoms)/(1molH)` = 6,87x10²² atoms H/n·cm³ -It depends of n number-

c)
`(0,01g)/(1cm^3)`×
`(1mole CH_(4))/(16,05g)`×
`(4molH)/(1molCH_(4))`×
`(6,022x10^(23)atoms)/(1molH)` = 1,50x10²¹ atoms H/cm³

I hope it helps!