Answer:
167.5g
Step-by-step explanation:
From the question, we know the mass of NaCl and the molar mass of NaCl, so we can calculate the number of moles of NaCl:
Moles = mass ÷ molar mass
The molar mass of NaCl can be calculated by adding the relative formula masses of the elements Na and Cl:
23.0 + 35.5 = 58.5
We can use the formula to find the number of moles of NaCl:
moles = 138 ÷ 58.5
= 2.35897...
Now, we need to find the mass of Cl2. Rearranging the formula of moles = mass ÷ molar mass
mass = moles × molar mass
Calculating the molar mass of Cl2 by adding the relative atomic masses:
35.5 + 35.5 = 71
Hence the mass is:
2.35897... × 71 = 167.5g (to 1dp)