If 10L of CO2 at STP and 50g sodium chloride react with excess ammonia and water, what is the limiting reactant and the mass of baking soda produced?
CO2 + H2O + NaCl + NH3 ==> NaHCO3 + NH4Cl
mols CO2 = 10 L/22.4 = 0.446
mols NaCl= 50/58.44 = 0.856
Now convert each to mols NaHCO3 separately.
First CO2 AS IF WE had all of the NaCl we needed.
0.446 mol CO2 x (1 mol NaHCO3/1 mol CO2) = 0.446 mol NaHCO3 produced.
Do the same for NaCl AS IF we had all of the CO2 we needed.
0.856 mol NaCl x (1 mol NaHCO3/1 mol NaCl) = 0.856 mol NaHCO3 produced.
You have two different answers; obviously one of them must be wrong. The correct answer in limiting reagent problem is ALWAYS the smaller value and the reagent producing that value is the limiting reagent. Therefore, CO2 is the limiting reagent.
Here is a worked example of a limiting reagent problem. Remember the steps. This worked example shows two ways to solve the problem.
http://www.jiskha.com/science/chemistry/limiting_reagent_problem.html
To find the limiting reactant and the mass of baking soda produced, we need to compare the amount of CO2 and sodium chloride used in the reaction.
1. Calculate the moles of CO2:
- Given volume: 10 L
- At STP (Standard Temperature and Pressure), 1 mole of any ideal gas occupies 22.4 L.
- Therefore, moles of CO2 = volume (in L) / 22.4
- In this case, moles of CO2 = 10 / 22.4
2. Calculate the moles of sodium chloride:
- Given mass: 50 g
- Molar mass of sodium chloride (NaCl) = 22.99 + 35.45 = 58.44 g/mol
- Moles of sodium chloride = mass (in g) / molar mass
- In this case, moles of sodium chloride = 50 / 58.44
3. To determine the limiting reactant, compare the moles of CO2 and sodium chloride.
- The reactant that produces the least amount of product is the limiting reactant.
- Divide the moles of CO2 by the stoichiometric coefficient of CO2 in the balanced equation.
- Divide the moles of sodium chloride by the stoichiometric coefficient of sodium chloride in the balanced equation.
- The chemical equation and stoichiometric coefficients are necessary to proceed. Please provide the balanced equation.
Once you provide the balanced equation, I can assist you in calculating the limiting reactant and the mass of baking soda produced.