Question

how many grams of hno₃ are in 2.005×10²² molecules of hno₃? show the conversions required to solve this problem and calculate the grams of hno₃. 2.005×10²² molecules hno₃×__× =? g hno₃ mass hno₃ = __ g hno₃

Explanation:

Step1: Convert molecules to moles

$n=\frac{2.005\times 10^{22}\text{ molecules}}{6.022\times 10^{23}\text{ molecules/mol}} = 0.0333$ mol

Step2: Calculate mass from moles

The molar - mass of $HNO_3$ is $M=(1 + 14+3\times16)\text{ g/mol}=63.01\text{ g/mol}$
$m = n\times M=0.0333\text{ mol}\times63.01\text{ g/mol}\approx2.09\text{ g}$

Answer:

2.09