PERCENT YIELDPERCENT YIELD

tells you the efficiency of a reactiontells you the efficiency of a reaction

formula:formula:

% yield = % yield = actual yield actual yield x 100 x 100 theoretical yieldtheoretical yield

PERCENT YIELDPERCENT YIELD

theoretical yield – amt of prod theoretical yield – amt of prod predictedpredicted to form based on balanced to form based on balanced equationequation

actual yield –actual yield – obtained by doing an experimentobtained by doing an experiment varies according to temp, pressure, varies according to temp, pressure,

purity of reactants, and side rxnspurity of reactants, and side rxns

CALCULATE % YIELDCALCULATE % YIELDPotassium carbonate reacts with HCl: Potassium carbonate reacts with HCl: write the balanced equation.write the balanced equation.

KK22COCO3(aq)3(aq)+ 2HCl+ 2HCl(aq)(aq)→ 2KCl→ 2KCl(aq)(aq)+ H+ H22O + COO + CO2(g)2(g)

When 45.8 g of KWhen 45.8 g of K22COCO33 is added to an is added to an

excess of HCl, 46.3 g KCl is recovered.excess of HCl, 46.3 g KCl is recovered.

Calc. % yield.Calc. % yield.

CALCULATE % YIELDCALCULATE % YIELDKK22COCO3(aq)3(aq)+ 2HCl+ 2HCl(aq)(aq)→ 2KCl→ 2KCl(aq)(aq)+ H+ H22O + COO + CO2(g)2(g)

45.8g K2CO3 x 1 mol K2CO3 x 2 mol KCl …

138.21g K2CO3 1 mol K2CO3

x 74.55g KCl = 49.4 g KCl 1 mol KCl

%yield = (46.3 g / 49.4 g) x 100 = 93.7%