Question

Determine the number of ch2cl2 molecules in 25.0 g ch2cl2.determine the number of ch2cl2 molecules in 25.0 g ch2cl2.

Answer 1

Answer is: there is 1,77·10²³ molecules of CH₂Cl₂.
m(CH₂Cl₂) = 25 g.
n(CH₂Cl₂) = m(CH₂Cl₂) ÷ M(CH₂Cl₂).
n(CH₂Cl₂) = 25 g ÷ 85 g/mol.
n(CH₂Cl₂) = 0,294 mol.
N(CH₂Cl₂) = n(CH₂Cl₂) · Na.
N(CH₂Cl₂) = 0,294 mol · 6,023 1/mol.
N(CH₂Cl₂) = 1,77·10²³.
n - amount of substance.
Na - Avogadro number.

Answer 2

Answer : The number of molecules of $CH_2Cl_2$ are, $1.77\times10^{23}$

Explanation : Given,

Mass of $CH_2Cl_2$ = 25 g

Molar mass of $CH_2Cl_2$ = 85 g/mole

First we have to calculate the moles of $CH_2Cl_2$.

$\text{Moles of }CH_2Cl_2=\frac{\text{Mass of }CH_2Cl_2}{\text{Molar mass of }CH_2Cl_2}=\frac{25g}{85g/mole}=0.294moles$

Now we have to calculate the number of molecules of $CH_2Cl_2$.

As, 1 mole of $CH_2Cl_2$ contains $6.022\times 10^{23}$ number of molecules of $CH_2Cl_2$

So, 0.294 mole of $CH_2Cl_2$ contains $0.294\times 6.022\times 10^{23}=1.77\times10^{23}$ number of molecules of $CH_2Cl_2$

Therefore, the number of molecules of $CH_2Cl_2$ are, $1.77\times10^{23}$