Question

Calculate the mass of chloroform that contains 1.00X10^12 molecules of chloroform

Answer 1

Molar mass of chloroform (CHCl3)
C = 1 * 12 = 12 a.m.u
H = 1 * 1 = 1 a.m.u
Cl = 3 * 35.5 = 106.5 a.m.u
Molar Mass (CHCl3) = 12 + 1 + 106.5 = 119.5 g / mol

Knowing that: The value of Avogadro's constant corresponds to approximately
`6,02*10^(23)` molecules, if chloroform contains
`1,00 * 10^(12)` molecules.
We have:


`1,00 * 10^(12) * 6,02 * 10^(23) = 6,02 * 10 ^ {35} molecules`

Now, how many grams are there in the chloroform molecule?

grams -------- molecules
119,5 →
`6,02 * 10^(23)`
x →
`6,02 * 10^(35)`


`6,02 * 10 ^ {23} * x = 119,5 * 6,02 * 10 ^(35)`

`6,02 * 10 ^ {23}x = 719,39 * 10^(35)`

`x = (719,39)/(6,02)*10^(35-23)`

`\boxed{x = 119,5*10^(12)grams}`