Question

question 6
0.1 pts
how many moles are in 45 grams of magnesium to the correct number of significant figures? input the numeric value.

Explanation:

Step1: Recall molar - mass formula

The formula to calculate the number of moles $n$ is $n=\frac{m}{M}$, where $m$ is the mass and $M$ is the molar mass. The molar mass of magnesium ($Mg$) is $M = 24.31\ g/mol$.

Step2: Substitute values

We are given $m = 45\ g$. Substituting into the formula $n=\frac{m}{M}$, we get $n=\frac{45\ g}{24.31\ g/mol}$.

Step3: Calculate the number of moles

$n=\frac{45}{24.31}\approx1.9\ mol$ (rounded to 2 significant figures since 45 has 2 significant figures).

Answer:

1.9