How concentration effects the rate of a chemical reaction

Preliminary work:

  For my preliminary work I tested which sized calcium carbonate pieces to use, Large, Medium or Powder, and what strength Hydrochloric acid to us, 1M or 2M.

Using 30ml of 2M acid, 3g of each of the particles had filled the measuring cylinder with hydrogen gas, the large bits filling it slowest and the powder filling it fastest.

Equipment:

  Gas Cylinder

  Conical flask with rubber tube

  50ml measuring cylinder

  10ml measuring cylinder

  6 100ml beakers

  Pipette

  Balance

  Stop clock

  Calcium Carbonate (large marble chips)

  2M hydrochloric acid

  Safety Goggles

Method

• Weigh 3g of Calcium Carbonate in each of the 100ml beakers
• Connect the conical flask to the gas cylinder via the rubber tube.
• Measure 30ml of hydrochloric acid in the 50ml measuring cylinder and put it in to the conical flask
• Add 1 beaker (3g) of calcium carbonate to the conical flask, close the bung and start the stop clock.
• Every 10 seconds measure the amount of gas in the gas cylinder until either the gas cylinder reaches 100ml+ (full) or the timer reaches 4 minutes.
• Empty and rinse the conical flask
• Measure 25ml of acid in the 50ml measuring cylinder and 5ml of water in the 10ml measuring cylinder and repeat.
• Measure 20ml of acid and 10ml of water and repeat.
• Measure 15ml of acid and 15ml of water and repeat.
• Measure 10ml of acid and 20ml of water and repeat.
• Measure 5ml of acid and 25ml of water and repeat.
• Repeat all 6 experiments at least twice for accurate results.

Analysis

  In conclusion, the more concentrated the acid is, the faster it reacts with the calcium carbonate, therefore meaning that with lower concentration, the rate is lower.

If I repeated this investigation I would repeat the experiments more to get a more accurate result, and possibly discount experiments that seem to have different results to the others