Question

Sodium and chlorine are very dangerous by themselves. However, when we combine them together in a chemical reaction, we get table salt: 2Na + Cl₂ → 2NaCl. If I want to make 100.0 g of my own salt, how much elemental chlorine would I need?

1) 100.0 g
2) 50.0 g
3) 25.0 g
4) 60.67 g
5) not enough information

Answer 1

To make 100.0 g of table salt, 60.67 g of chlorine would be needed, based on the formula mass computation of NaCl (58.44 amu) and the 1:1 molar ratio of sodium to chlorine in the compound.

Step-by-step explanation:

To calculate how much elemental chlorine is needed to make 100.0 g of table salt (NaCl), we first determine the formula mass of sodium chloride. The formula mass is 58.44 amu, which is the sum of the atomic masses of one sodium atom (22.99 amu) and one chlorine atom (35.45 amu).

Since table salt has a 1:1 ratio of sodium to chlorine and the chemical reaction is 2Na + Cl₂ → 2NaCl, the mass of chlorine needed would be in the same proportion to the mass of sodium in NaCl. For every 58.44 grams of NaCl, 35.45 grams are chlorine. So to make 100.0 g of NaCl, we can set up a proportion:

(35.45 g Cl / 58.44 g NaCl) = (x g Cl / 100.0 g NaCl)

Solving for x gives us: x = (35.45 g Cl / 58.44 g NaCl) × 100.0 g NaCl = 60.66 g Cl
(p)60.66 g Cl is approximately equal to 60.67 g Cl, so the correct answer is (4) 60.67 g.