Question

The molar mass of HF is 20.01 g/mol. How many moles of Sn are required to react with 40 g of HF?

Answer 1

1 mole of Sn

Step-by-step explanation:

Tin (Sn) reacts with hydrogen fluoride (HF) to form stannous fluoride (SnF2), a compound that is used in toothpaste to strengthen tooth enamel. Another product of this reaction is the H2 that is released as gas.

Sn + HF ⇒ SnF₂ + H₂

Once we have the equation, we balance it on both sides.

Sn + 2 HF ⇒ SnF₂ + H₂

To make the following calculation we have to find out how much a mole of Sn weighs.

Sn= 118.69 g/mol

HF = 20.01 g/mol

Sn + 2 HF ⇒ SnF₂ + H₂

118.69 g 2 x 20.01 g

118.69 g <---- 40.02 g

Every 2 moles of HF (40.02g) reacts 1 mole of Sn.

Answer 2

Sn + 2HF ----> SnF₂ + H₂
119g 2×20g

1 mole Sn (119g) is required to react with 2 moles (40g) of HF.

:)