Question

Given the problem below, what would the first step be in solving it?

How many grams of NaCl will be produced from 18.0 g of Na and 23.0 g Cl2?

2Na + Cl2 --> 2NaCI
Question 3 options:


Convert to moles


Use the mole ratio


Start with the given information 18 g Na and 23 g Cl2


Convert to grams

Answer 1

First step would be convert to moles

Final Answer: 37.8 g of NaCl

Step-by-step explanation:

The reaction is:

2Na + Cl₂ → 2NaCI

We convert the mass of each reactant to moles:

18 g . 1mol /23g = 0.783 moles of Na

23g . 1mol / 70.9g = 0.324 moles of chlorine

We use the mole ratio to determine the limiting reactant:

Ratio is 2:1. 2 moles of Na react to 1 mol of chlorine

Then, 0.783 moles of Na, may react to (0.783 . 1)/2 = 0.391 moles.

Excellent!. We need 0.391 moles of Cl₂ and we only have 0.324 moles available. That's why the Cl₂ is our limiting reactant.

We use the mole ratio again, with the product side. (1:2)

1 mol of Cl₂ can produce 2 moles of NaCl

Then, our 0.324 moles of gas, may produce (0.324 . 2)/1 = 0.648 moles

Finally, we convert the moles to grams:

0.648 mol . 58.45g/mol =