hydrogen peroxide + manganese dioxide oxygen + water 2H2
O2 + MnO2 O2 + 2H2 Method
1. Fill the water trough and large graduated cylinder with water as shown in Fig. 21.12.
2. Using the small graduated cylinder, place 50 cm3
3. Using the mass balance, measure out 1 g of manganese dioxide.
4. Once ready to start, quickly place the manganese dioxide into the conical flask. Secure the rubber bung onto the top of the conical flask and start the timer. Collect the oxygen gas produced.
5. Measure the volume of gas at regular intervals. Record your results. 6. Follow steps 2–5, but this time do not add a catalyst. Record your results. 7. Test for oxygen – it relights a glowing splint.
1
Conical flask
Delivery tube Clamp
Graduated cylinder
Oxygen gas collected of
the hydrogen peroxide into the conical flask. Set up the delivery tube as shown in Fig. 21.12.
SAFETY • Wear gloves when handling the hydrogen peroxide, as it is corrosive.
O
Hydrogen peroxide solution 2
Conical flask
Water trough Delivery tube
Oxygen gas collected
Water trough
Hydrogen peroxide solution and manganese dioxide
:Fig. 21.12 To investigate how the presence of a catalyst affects the rate of reaction j Go to page 58 of your Experimental Investigations Log to write up this investigation.