Question

calculate the number of molecules present
4.4g of coa
23
At mass C = 12 () = 160, NA=6.02 x 1023 mol-i​

Answer 1

Need to FinD :-

• The number of molecules present.

$\red{\frak{Given}}\Bigg\{ \sf There \ is \ 4.4g \ of \ CO_2 .$

We know that the Molecular weight of Carbon di oxide is 44 grams , that is ,

$\to\red{\sf Molecular\ wt. \ = \ 12g + (16g)(2) = 44g }$

Also we know the Number of moles is given by Given weight in grams divided by molecular weight. And the number of moles will be multiplied by Avogrado's Number $\bf ( N_A)$ whose value is 6.022 × 10²³ to obtain the number of molecules present .

• Using formula of no. of moles :-

$\sf\dashrightarrow n_{(moles)}=\dfrac{Given\ wt.}{Molecular \ wt.}\\\\\sf\dashrightarrow n_{(moles)}= \dfrac{4.4g}{44g} \\\\\sf\dashrightarrow n_{(moles)}= \dfrac{44}{440} \\\\\sf\dashrightarrow n_{(moles)}= 0.1 \ moles \\\\\sf\dashrightarrow n_{(molecule s)}=n_{(moles)}\times N_A \\\\\sf\dashrightarrow \boxed{\pink{\frak{ n_{(molecule s)}= 0.1N_A}}}$