CHEMISTRY

• TITLE:

  investigation into the effect of acid concentration on reaction rates.
• AIM:

  To investigate how increasing the concentration of acid affects the rate at which a reaction occurs.
• UNDERLYING CHEM 1 (reactants)

  In order for a chemical reaction to occur the reactant particles must collide with sufficient energy and at the right angle. The speed at which the reaction happens is called the reaction rate and will be determined by the frequency at which the collisions happen
• UNDERLYING CHEM 2(pH)

  Increasing the concentration of acid will decrease the pH. The lower the pH means there are more H+ ions which means more particles to collide. So increasing this will cause the particles to collide more frequently.
• UNDERLYING BIO 3(frequency)

  Some collisions do not end with a reaction because of factors such as energy and angle so increasing the frequency of collisions increases the number of collisions and also the chances of particles colliding right and therefore speeding up the reaction.
• UNDERLYING CHEM 4(GAS)

  Gas will be produced because when an acid reacts with a metal carbonate it produces a salt, water and CO2(a gas). So by measuring the volume of gas produced in the set period we will be able to come to a conclusion about how fast the reaction is happening.
• UNDERLYING CHEM 5(EQNS)

  Acid + metal carbonate= salt + water + carbon dioxide

  2HCL + CaCO3 = H2O + CaCl2 + CO2
• METHOD:

  In order to do this experiment, I put three different concentrations of acid into 3 different conical flasks and put marble chips in each one. We then measured the volume of gas produced after 1 minute by using a gas syringe.
• ANALYSIS

  From both my second source and my own results you can see that as the concentration of acid increases, the reaction rate also increases. I can tell this from my second source graph because the line showing the higher concentration is steeper than the line showing the low concentration showing that the higher concentration took less time for the reaction to complete. This agrees with my own result that show more gas is produced in the set time using a high concentration than when using a low concentration meaning the reaction rate is faster.
• CONCLUSION:

  In conclusion increasing the concentration of acid increases the rate at which the reaction occurs increases as well. We can see this because as this concentration of acid was increased, a larger volume of gas was produced in the set period. This tells us the reaction was happening faster.
• EVALUATION:

  Next time we would control the size of marble chips better in each flask and then the repeat. As particle size can also affect reaction rate this would have caused a decrease in how reliable our results were.
• Graph

  bottom axis = concentration of acid

  y-axis = reaction rate (s)

  jumps of 0.1
• reaction rate

  change/time for change