Stoichiometry Review Worksheet 1. Solid tin reacts with diatomic chlorine to produce tin (IV) chloride. If 95 grams of tin reacts in an excess of chlorine, what mass of tin (IV) chloride is produced? 2. Sodium Bicarbonate decomposes when heated for form sodium carbonate, water, and carbon dioxide gas. If 1.8 moles of carbon dioxide are produced, how many moles of sodium bicarbonate were decomposed?3. Iron (III) oxide reacts with magnesium to produce magnesium oxide and iron. If 0.25 moles of magnesium are consumed, what mass of iron will be produced?
The Correct Answer and Explanation is :
Solutions to Stoichiometry Problems:
1. Reaction of Tin and Chlorine
Balanced Equation:
[ \text{Sn (s) + 2 Cl}_2 \text{(g)} \rightarrow \text{SnCl}_4 \text{(l)} ]
Given Data:
- Mass of tin (( \text{Sn} )): ( 95 \, \text{g} )
- Molar mass of tin (( \text{Sn} )): ( 118.71 \, \text{g/mol} )
- Molar mass of tin(IV) chloride (( \text{SnCl}_4 )): ( 260.51 \, \text{g/mol} )
Steps:
- Convert the mass of tin to moles:
[ \text{Moles of Sn} = \frac{95}{118.71} \approx 0.8 \, \text{mol} ] - Use the stoichiometric ratio (( 1 \, \text{Sn} : 1 \, \text{SnCl}_4 )):
[ \text{Moles of SnCl}_4 = 0.8 \, \text{mol} ] - Convert moles of ( \text{SnCl}_4 ) to mass:
[ \text{Mass of SnCl}_4 = 0.8 \times 260.51 \approx 208.4 \, \text{g} ]
Answer: ( \text{208.4 g of SnCl}_4 )
2. Decomposition of Sodium Bicarbonate
Balanced Equation:
[ 2 \text{NaHCO}_3 \text{(s)} \rightarrow \text{Na}_2\text{CO}_3 \text{(s)} + \text{H}_2\text{O (l)} + \text{CO}_2 \text{(g)} ]
Given Data:
- Moles of ( \text{CO}_2 ): ( 1.8 \, \text{mol} )
Steps:
- Use the stoichiometric ratio (( 2 \, \text{NaHCO}_3 : 1 \, \text{CO}_2 )):
[ \text{Moles of NaHCO}_3 = 1.8 \times 2 = 3.6 \, \text{mol} ]
Answer: ( 3.6 \, \text{mol of NaHCO}_3 )
3. Reaction of Iron(III) Oxide with Magnesium
Balanced Equation:
[ \text{Fe}_2\text{O}_3 \text{(s)} + 3 \text{Mg (s)} \rightarrow 3 \text{MgO (s)} + 2 \text{Fe (s)} ]
Given Data:
- Moles of magnesium (( \text{Mg} )): ( 0.25 \, \text{mol} )
- Molar mass of iron (( \text{Fe} )): ( 55.85 \, \text{g/mol} )
Steps:
- Use the stoichiometric ratio (( 3 \, \text{Mg} : 2 \, \text{Fe} )):
[ \text{Moles of Fe} = 0.25 \times \frac{2}{3} \approx 0.167 \, \text{mol} ] - Convert moles of ( \text{Fe} ) to mass:
[ \text{Mass of Fe} = 0.167 \times 55.85 \approx 9.33 \, \text{g} ]
Answer: ( 9.33 \, \text{g of Fe} )
Explanation:
Stoichiometry relies on the conservation of mass and molar relationships in a chemical reaction. For each problem, the balanced chemical equation is used to determine mole ratios, converting between moles and mass using molar masses. Steps involve:
- Converting given quantities (mass or moles) to moles.
- Applying mole ratios from the balanced equation.
- Converting moles back to desired units, like grams, using molar mass.
These steps ensure precise calculations and highlight the relationships between reactants and products.