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

Answer:

a) 6,69x10²² atoms H/cm³

b) 6,87x10²² atoms H/n·cm³

c) 1,50x10²¹ atoms H/cm³

Explanation:

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

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

b) As oil formula is $C_{n}H_{2n}$

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

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

I hope it helps!