Question

for the each element, convert the given mole amount to grams. how many grams are in 0.0564 mol of potassium? mass: how many grams are in 0.550 mol of cobalt? mass: how many grams are in 0.790 mol of selenium? mass:

Explanation:

Step1: Recall molar - mass formula

The formula to convert moles to mass is $m = n\times M$, where $m$ is the mass in grams, $n$ is the number of moles, and $M$ is the molar mass in g/mol.

Step2: Find molar mass of potassium

The molar mass of potassium (K) is approximately $M_{K}=39.10\ g/mol$. Given $n_{K} = 0.0564\ mol$, then $m_{K}=n_{K}\times M_{K}=0.0564\ mol\times39.10\ g/mol = 2.20524\ g\approx2.21\ g$.

Step3: Find molar mass of cobalt

The molar mass of cobalt (Co) is approximately $M_{Co}=58.93\ g/mol$. Given $n_{Co}=0.550\ mol$, then $m_{Co}=n_{Co}\times M_{Co}=0.550\ mol\times58.93\ g/mol = 32.4115\ g\approx32.4\ g$.

Step4: Find molar mass of selenium

The molar mass of selenium (Se) is approximately $M_{Se}=78.96\ g/mol$. Given $n_{Se}=0.790\ mol$, then $m_{Se}=n_{Se}\times M_{Se}=0.790\ mol\times78.96\ g/mol = 62.3784\ g\approx62.4\ g$.

Answer:

For potassium: 2.21 g
For cobalt: 32.4 g
For selenium: 62.4 g