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Percentage Yield


Use balanced chemical equations to calculate the masses of substances which react, as well as the masses of products formed.


Lead (II) Nitrate reacts with sodium hydroxide to form lead (II) hydroxide. The lead (II) hydroxide reacts with sodium hypochlorite solution to form a precipitate of lead (IV) oxide.

The reactions are: Pb(NO3)2(aq) + 2NaOH(aq) ⟶ Pb(OH)2(aq) + 2NaNO3(aq)

Pb(OH)2(aq) + NaOCℓ(aq) ⟶ PbO2(s) + NaCℓ(aq) + H2O(ℓ)

0,5 M Pb(NO3)2(aq) and 0,5 M NaOH(aq) is used in the experiment.

Use the formula: c = m/MV and determine m = cMv for Pb(NO3)2(aq): m = (0,5)(331)(0,1) = 16,55 g For NaOH(aq) m = (0,5)(40)(0,1) = 2 g

The solution is filtered through filter paper and the mass of the dry PbO2(s) is determined – actual mass. Learners use the balanced equations to determine the theoretical mass of lead (II) oxide.

Percentage yield = (actual yield)/ (theoretical yield) x 100%


To determine the percentage yield of PbO2(s) that forms from Pb(NO3)2(s)

Time Allocation: Practical work –45 Min
Total Duration: 2 Days


  • 2 x 250 ml Conical flasks
  • 1 x 250 ml Measuring Cylinder
  • 2 x Weighing Trays
  • 1 x Chattaway Spatula
  • 1 x Glass stirring rod 300mm
  • Filter Paper
  • 90mm Funnel
  • Electronic Scale
  • 25g Lead(II)nitrate (Pb(NO3)2(s))
  • 25g Sodium Hydroxide (NaOH)(s)
  • 250ml Distilled Water


  1. Take two 250 ml conical flasks, ensure they are clean.
  2. Label both flasks with your group name and A- Lead Nitrate, B-Sodium Hydroxide for each.
  3. Measure and record the mass of each dry, empty flask (they may be different).
  4. Also measure the mass of 1 piece of filter paper.
  5. Place each empty flask on scale, measure mass again, increase mass by 1.3g (Approximate mass of 1.3g is fine).
  6. Then add Lead (II) Nitrate into a weighing tray until you measure out 1.3g of lead nitrate till the scale balances (Approximate mass of 1.3g is fine) place it into the flask.
  7. Repeat the above step with the second flask using Sodium Hydroxide Pearls and a clean weighing tray.
  8. Add approximately 120 mL of water with the 250ml measuring cylinder to each flask and stir with glass stirring rod.
  9. Combine the two beakers into one. (pour beaker B into A)
  10. Rinse any remaining reactants from beaker B with distilled water, this will not affect your results.
  11. Secure the funnel in the neck of the conical flask.
  12. Fold the filter paper in halves, then in quarters and separate one layer from the other and place in the funnel.
  13. Insert the funnel with filter paper into a flask.
  14. Carefully filter the contents from beaker A into the flask.
  15. Be sure to rinse any of the product left with distilled water in the beaker into the filter – let dry overnight
  16. Day Two – determine the mass of product on dried filter paper (total mass = residue + filter paper)


Solid caustic soda (NaOH(s)) is corrosive – it causes severe burns and is dangerous to the eyes.
  • The dissolution process is highly exothermic.
  • Lead nitrate is poisonous – work in a fume cupboard and do not inhale the fumes.
  • Wear gloves and safety goggles – avoid skin contact.
  • Lead compounds should NOT be washed away in drains or rubbish bins – store in a container for collections by experts in waste-removal.