the compound tin(II)fluoride,or stannous fluoride,once was a common ingredient in toothpaste.It is produced according to the following reactions:
Sn(s)+2HF(g)->SnF2(s)+H2(g)
if 45.0 grams og HF react with Sn,how many grams of stannous fluoride are produced?
To determine the amount of stannous fluoride produced when 45.0 grams of HF reacts with Sn, we need to follow these steps:
Step 1: Convert the given mass of HF to moles.
To convert grams to moles, we use the molar mass of HF. The molar mass of hydrogen (H) is 1.008 g/mol, and the molar mass of fluorine (F) is 18.998 g/mol. Adding these two values gives us a molar mass of 20.006 g/mol for HF.
Using the equation:
moles of HF = mass of HF / molar mass of HF
moles of HF = 45.0 g / 20.006 g/mol
moles of HF ≈ 2.249 mol (rounding to the appropriate number of significant figures)
Step 2: Use stoichiometry to determine the moles of stannous fluoride produced.
Based on the balanced chemical equation, we can see that the mole ratio between HF and SnF2 is 2:1. This means that for every 2 moles of HF, 1 mole of SnF2 is produced.
Using this mole ratio:
moles of SnF2 = moles of HF / 2
moles of SnF2 = 2.249 mol / 2
moles of SnF2 ≈ 1.124 mol (rounding to the appropriate number of significant figures)
Step 3: Convert the moles of SnF2 to grams.
To convert moles to grams, we use the molar mass of SnF2. The molar mass of tin (Sn) is 118.71 g/mol, and the molar mass of fluorine (F) is 18.998 g/mol. Accordingly, the molar mass of SnF2 is:
molar mass of SnF2 = (molar mass of Sn) + (2 * molar mass of F)
molar mass of SnF2 = 118.71 g/mol + (2 * 18.998 g/mol)
molar mass of SnF2 = 156.706 g/mol
Using the equation:
mass of SnF2 = moles of SnF2 * molar mass of SnF2
mass of SnF2 = 1.124 mol * 156.706 g/mol
mass of SnF2 ≈ 176.32 g (rounding to the appropriate number of significant figures)
Therefore, approximately 176.32 grams of stannous fluoride will be produced when 45.0 grams of HF reacts with Sn.
Worked example of a simple stoichiometry problem.
http://www.jiskha.com/science/chemistry/stoichiometry.html