Gravimetric Determination of Sodium Carbonate
Calculations: Show your work for all calculations, include the equation and the calculation. Be very
neat, complete and pay attention to sig. figs.
1. Write a balanced equation for the double replacement reaction. Use appropriate symbols to
show the state of each reactant and product. Which product was the precipitate?
SrCl₂ +
Na₂CO3
2.
→ Sr CO₂ +2Na cl
From the difference in mass for each funnel, calculate the mass of each precipitate sample.
Show your work and include units and the formula for the precipitate.
25.556-24-836=0.72, 25.852-25.108=6.744
3. Calculate the average mass of the two samples.
0.72+0. чии
5.
2
crucible!
= 0.732
4. From the verage mass of precipitate) calculate the moles of precipitate
grams from #3
1 mole
molar mass STCO,
From the balanced equation, calculate the moles of reactant sodium carbonate
moles STCO₂ #4
coefficient Na₂CO
coefficient SrCO,
CML Srco
Amol Nascos
Imal Srco3
6. Calculate the concentration (molarity) of the original unknown solution of sodium carbonate.
(Molarity, abbreviated as M, is moles solute per liter of solution.) (M =
moles Na₂CO₂
volume Na₂CO, from data 0.0150L
0.35
crucible2
7. Obtain the known value for the concentration of the unknown solution from the instructor and
calculate your percent error as shown on page xvi of your lab manual. (accuracy)
lexperimental value-accepted valuel) x 100
laccepted value]
0 35
X100 -