a penny has a mass of 2.50 g and the moon has a mass of 7.35×10²² kg. use this information to answer the…

Explanation:

Step1: Recall Avogadro's number

1 mole contains $6.022\times 10^{23}$ entities.

Step2: Calculate mass of 1 - mole of pennies

Given mass of 1 penny is $m = 2.50$ g. Mass of 1 - mole of pennies $M_1=2.50\ g\times6.022\times 10^{23}$. $M_1 = 1.5055\times10^{24}$ g. Rounding to 3 significant digits (since 2.50 has 3 significant digits), $M_1=1.51\times 10^{24}$ g.

Step3: Calculate number of moles of pennies equal to Moon's mass

Mass of the Moon $M_{moon}=7.35\times 10^{22}$ kg. First convert it to grams: $M_{moon}=7.35\times 10^{25}$ g. Let the number of moles of pennies be $n$. Then $n=\frac{M_{moon}}{M_1}=\frac{7.35\times 10^{25}\ g}{1.51\times 10^{24}\ g}$. $n=\frac{7.35}{1.51}\times10^{25 - 24}\approx4.87\times 10^{1}$.

Answer:

$1.51\times 10^{24}$ g $49$