Controlled Variables Lab Report
Variables
Independent variable: The temperature of HCl is going to be changed. The temperature 10℃,30℃,50℃,70℃ and 90℃ of hydrochloric acid will be used to conduct the experiment. The hot plate is going to be used to reach 30℃,50℃,70℃ and 90℃, that are higher than the room temperature. Ice cubes can be used with water bath to make 10℃ hydrochloric acid.
Dependent variable: The time it takes for carbon dioxide gas produces up to 20mL of gas syringe is going to be measured. It will be measured by using a gas syringe and stopwatch. As soon as the reaction starts, I am going to start the stopwatch and when the gas syringe 20mL mark is reached with gas, I am going to stop the stopwatch.
Controlled variables: Volume of HCl
The volume of hydrochloric acid should be kept constant. Different volume of HCl reacting with calcium carbonate will result in fewer or more collisions between particles, so the calculated rate will …show more content…
be affected. I am always going to use 10.0mL of HCl that is measured in the measuring cylinder. Ensure this not contaminated.
Mass of CaCO3
The mass of calcium carbonate should be kept constant.
Different mass of calcium carbonate reacting with hydrochloric acid will change the mol of reactant. It will be affecting the rate if it becomes limiting reagent. I am always going to use 3.00g of calcium carbonate weighed on the electronic balance. Ensure calcium carbonate is pure supply, not contaminated.
Surface area of CaCO3
The surface area of calcium carbonate should be kept constant. Different surface area of calcium carbonate will change the number of collisions between particles, as the calcium carbonate reactants have different exposed area of colliding with hydrochloric acid reactants. I am going to make the calcium carbonate powder with Mortar and Pestle.
Concentration of HCl
The concentration of HCl should be kept constant. Different concentration of HCl will change the chance of collisions between particles. As the concentration is high, the number of collisions between the particles is going to increase. I am always going to use 1moL of hydrochloric
acid.
Use the equipment with the same size
Independent variable: The temperature of HCl is going to be changed. The temperature 10℃,30℃,50℃,70℃ and 90℃ of hydrochloric acid will be used to conduct the experiment. The hot plate is going to be used to reach 30℃,50℃,70℃ and 90℃, that are higher than the room temperature. Ice cubes can be used with water bath to make 10℃ hydrochloric acid.
Dependent variable: The time it takes for carbon dioxide gas produces up to 20mL of gas syringe is going to be measured. It will be measured by using a gas syringe and stopwatch. As soon as the reaction starts, I am going to start the stopwatch and when the gas syringe 20mL mark is reached with gas, I am going to stop the stopwatch.
Controlled variables: Volume of HCl
The volume of hydrochloric acid should be kept constant. Different volume of HCl reacting with calcium carbonate will result in fewer or more collisions between particles, so the calculated rate will …show more content…
be affected. I am always going to use 10.0mL of HCl that is measured in the measuring cylinder. Ensure this not contaminated.
Mass of CaCO3
The mass of calcium carbonate should be kept constant.
Different mass of calcium carbonate reacting with hydrochloric acid will change the mol of reactant. It will be affecting the rate if it becomes limiting reagent. I am always going to use 3.00g of calcium carbonate weighed on the electronic balance. Ensure calcium carbonate is pure supply, not contaminated.
Surface area of CaCO3
The surface area of calcium carbonate should be kept constant. Different surface area of calcium carbonate will change the number of collisions between particles, as the calcium carbonate reactants have different exposed area of colliding with hydrochloric acid reactants. I am going to make the calcium carbonate powder with Mortar and Pestle.
Concentration of HCl
The concentration of HCl should be kept constant. Different concentration of HCl will change the chance of collisions between particles. As the concentration is high, the number of collisions between the particles is going to increase. I am always going to use 1moL of hydrochloric
acid.
Use the equipment with the same size