Question

Be sure to answer all parts. Calcium dihydrogen phosphate, Ca(H2PO4)2, and sodium hydrogen carbonate, NaHCO3, are ingredients of baking powder that react with each other to produce CO2, which causes dough or batter to rise: Ca(H2PO4)2(s) + NaHCO3(s) → CO2(g) + H2O(g) + CaHPO4(s) + Na2HPO4(s)[unbalanced] If the baking powder contains 31.0% NaHCO3 and 35.0% Ca(H2PO4)2 by mass: (a) How many moles of CO2 are produced from 9.66 g of baking powder? mol CO2 (b) If 1 mol of CO2 occupies 37.0 L at 350°F (a typical baking temperature), what volume of CO2 is produced from 9.66 g of baking powder?

Answer 1

Answer – We are given, reaction –

Ca(H₂PO₄)₂(s) + 2 NaHCO₃(s) ----> 2 CO₂(g) + 2 H₂O(g) + CaHPO₄(s) + Na₂HPO₄(s)

Mass percent of NaHCO₃(s) = 31.0% , mass % of Ca(H₂PO₄)₂(s) = 35.0 %

a) Mass of baking powder = 9.66 g , moles of CO₂ =

now we need to calculate the mass of each reactant

mass of NaHCO₃(s) = 31.0%*9.66 g / 100 %

                                 = 2.995 g

mass of Ca(H₂PO₄)₂(s) = 35.0 % 9.66 g / 100 %

                                      = 3.381 g

Moles of NaHCO₃(s) = 2.995 g / 84.00 g.mol^-1

                                   = 0.0356 moles

Moles of Ca(H₂PO₄)₂(s) = 3.381 g / 234.05 g.mol^-1

                                       = 0.0144 moles

Now we need to calculate the limiting reactant

Moles of CO₂ from Ca(H₂PO₄)₂(s)

We know

1 moles of Ca(H₂PO₄)₂(s) = 2 moles of CO₂

So, 0.0144 moles of Ca(H₂PO₄)₂(s) = ?

= 0.0288 moles of CO₂

Moles of CO₂ from the NaHCO₃(s)

1 moles of NaHCO₃(s) = 2 moles of CO₂

So, 0.0356 moles of NaHCO₃(s) = ?

= 0.0356 moles of CO₂

So, the lowest moles of the CO₂ from the Ca(H₂PO₄)₂(s) , so limiting eactant is Ca(H₂PO₄)₂(s) .

Moles of CO₂ = 0.0288 moles

So, 0.0288 moles of CO₂ are produced from 9.66 g of baking powder.

b) We are given, 1 moles of CO₂ = 37.0 L at 350°F , mass of baking powder = 9.66 g

We already calculated moles of CO₂ produced from 9.66 g of baking powder

So,

1 moles of CO₂ = 37.0 L

0.0288 moles of CO₂ = ?

= 1.07 L

So, 1.07 L volume of CO₂ is produced from 9.66 g of baking powder