Answer:
0.509 (to 3dp)
Step-by-step explanation:
The formula for moles is:
moles = mass ÷ molar mass
The molar mass of NaCl can be calculated by adding the relative atomic masses of each element in the compound, which you can find in a periodic table:
molar mass = 23.0 + 35.5 = 58.5
Now, we can find the number of moles of NaCl in 29.8g:
moles = 29.8 ÷ 58.5 = 0.509 (to 3dp)