1Write a balanced chemical equation for the reaction between calcium carbonate and ethanoic acid
CaCO₃ + 2CH₃COOH → Ca(CH₃COO)₂ + CO₂ + H₂O
2How can the volume of gas produced during a reaction be measured?
Collect the gas in either a gas syringe or an upturned water-filled measuring cylinder in a water trough
3What safety precautions should be taken when investigating the rate of reaction between ethanoic acid and calcium carbonate?
Wear eye protection; keep the room well ventilated; avoid naked flames; ensure the delivery tube isn't blocked; avoid acid contact with skin cuts; clean up spills and broken glass
4Why must the bung be rapidly placed in the opening of the reaction vessel when using a gas syringe?
To reduce the amount of gas that is lost before the bung is inserted
5How can the amount of substance be calculated using mass?
Number of moles = mass (g) ÷ molar mass (Mr)
6How does increasing the mass of calcium carbonate affect the volume of gas produced?
- If CaCO₃ is limiting reagent, increasing the mass of CaCO3will increase the volume of CO₂
-if CaCo3 is in excess, increasing the mass of CaCO3 will have no effect on the volume of CO2 produced
7What equation links amount of substance and concentration?
Number of moles = concentration (mol dm⁻³) × volume (dm³)
8How can the number of moles of a gas be calculated if its volume at room temperature and pressure is known?
Number of moles = volume (dm³) ÷ 24
9What are possible sources of error when using a gas syringe to measure gas volume?
- Plunger may not move freely
- Gas may escape before bung is inserted
– Bung may not be airtight
– Some CaCO₃ may be lost during transfer
10the volume of gas produced when ethanoic acid reacts with calcium carbonate is being measured using a gas syringe. What are the possible sources of error in this experiment
- CaCO3 was lost during the transfer
– Gas may escape before bung is inserted
– Bung may not be airtight
11Suggest one reason why the mass of calcium carbonate used may be lower than the recorded value.
– Some CaCO₃ may be lost during transfer
12How can gas loss before bung insertion be avoided?
Place one reactant under an upturned container inside the beaker, insert the bung, then knock over the container to start the reaction safely
13what is the method to find the volume of one mole of carbon dioxide gas (include steps)
1-Measure 30 cm³ of 1 mol dm⁻³ ethanoic acid and transfer to a conical flask.
2-Attach conical flask to gas syringe or use collection over water method
3-Measure the mass of a weighing bottle with approx 0.05 g of calcium carbonate
4-Add the calcium carbonate to the conical flask - quickly resealing the bung so no gas escapes
5-Measure the final total volume of gas
6-Reweigh the empty weighing bottle test tube from step 3
7-Repeat the experiment several more times, increasing the mass of calcium carbonate by about 0.05 g each time.