Question

A chemist reacts sodium metal and chlorine gas to form salt according to the balanced chemical equation 2Na + Cl2 → 2NaCl.

If the chemist has 35 g Na, what mass of chlorine must they use to react completely with the sodium? Type in your answer using the correct number of significant figures.

35.0 g Na =
g Cl2
ANSWER= 54

Answer 1

To find the mass of chlorine that must be used to react completely with the 35 g of sodium, we can use the mole ratio from the balanced chemical equation.

2Na + Cl2 -> 2NaCl

1 mole Na : 1 mole Cl2

We know that 1 mole of sodium has a mass of 22.99 g, so we can find the number of moles of sodium:

moles = mass / molar mass

moles = 35.0 g / 22.99 g/mol

moles = 1.52 moles

Since the mole ratio is 1:1, we know that the number of moles of chlorine is also 1.52 moles. To find the mass of chlorine, we multiply the number of moles by the molar mass of chlorine:

mass = moles * molar mass

mass = 1.52 moles * 35.45 g/mol

mass = 53.95 g

So, the chemist must use 54 g (3 significant figures) of chlorine to react completely with the 35 g of sodium.