Question

1. How many grams are in 1.7 x 10^23 particles of Cl2?

Answer 1

Answer: 1. 20.0 grams

2. 0.272 moles

3. B) Mass --> Moles --> Volume

Explanation:

According to avogadro's law, 1 mole of every substance weighs equal to molecular mass and contains avogadro's number $6.023\times 10^{23}$ of particles.

To calculate the number of moles, we use the equation:

$\text{Number of moles}=\frac{\text{Given molecules}}{\text{Avogadros number}}$ or

$\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}$ or  

Putting in the values we get:

1. $\text{Number of moles of} Cl_2=\frac{1.7\times 10^{23}}{6.023\times 10^{23}}=0.282moles$

Mass of $Cl_2=moles\times {\text {Molar mass}}=0.282mol\times 71g/mol=20.0g$

2. $\text{Number of moles of NaCl}=\frac{3.28\times 10^{23}}{2\times 6.023\times 10^{23}}=0.272moles$

3. $\text{Number of moles of water}=\frac{26g}{18g/mol}=1.44moles$

Volume of water =$moles\times {\text {Molar volume}}=1.44mol\times 22.4L/mol=32.4L$