how many molecules of methane, ch4, are in 125 g ch4? (1 mol ch4 = 16.04 g) (1 mol ch4 = 6.02×10^23…

how many molecules of methane, ch4, are in 125 g ch4? (1 mol ch4 = 16.04 g) (1 mol ch4 = 6.02×10^23 molecules) ?×10^? molecules ch4 enter the coefficient in the green box and the exponent in the yellow box.

how many molecules of methane, ch4, are in 125 g ch4? (1 mol ch4 = 16.04 g) (1 mol ch4 = 6.02×10^23 molecules) ?×10^? molecules ch4 enter the coefficient in the green box and the exponent in the yellow box.

Answer

Answer:

Coefficient (green): 4.68 Exponent (yellow): 24

Explanation:

Step1: Calculate moles of CH4

$n=\frac{m}{M}$, where $m = 125\ g$ and $M=16.04\ g/mol$. So $n=\frac{125\ g}{16.04\ g/mol}\approx7.79\ mol$.

Step2: Calculate number of molecules

We know that 1 mol of any substance contains $6.02\times 10^{23}$ molecules. So the number of molecules of $CH_4$ is $N = n\times N_A$, where $n = 7.79\ mol$ and $N_A=6.02\times 10^{23}\ molecules/mol$. Then $N=7.79\times6.02\times 10^{23}=46.8\times 10^{23}=4.68\times 10^{24}$ molecules.