Question

calculate the grams of NaCl in a sample containing 1.2x10^24

Answer 1

1 mole of NaCl = 6.02×10²³ molecules

58.5g of NaCl = 6.02×10²³ molecules

xg of NaCl = 1.2×10²⁴ molecules

x = $\dfrac{1.2×10²⁴×58.5}{6.02×10²³}$

= 2×58.5g = 117g

Therefore, 1.2×10²⁴ molecules of NaCl has a mass of 117g.