The molar mass of HF is 20. 01 g/mol, (a) 1 mole of Sn is required to react completely with 40 g of HF.
Molar mass of HF = 20. 01 g/mol
Mass of HF = 40 g
Number of moles of Sn = ?
Write the balanced chemical equation
Sn + 2HF → SnF₂ + H₂
one mole of Sn is required to react with two moles of HF
Find number of moles of HF
number of moles = mass / molar mass
number of moles of HF = 40 g / 20. 01
number of moles of HF = 2.0 moles
As the molar ratio of Sn and HF 1 : 2
There are 2 moles of HF, and from the molar ratio, it is clear that the number of moles of Sn is half of HF.
So the number of moles of Sn = 2 × 1/2
number of moles of Sn = 1 mol
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