Factors Affecting Reaction Rate
Purpose: The purpose of this lab is to determine the effect that varying concentration / temperatures have on the rate of a reaction.
determine the effect that varying concentration/temperatures have on the rate of a reaction.
Material/equipments:
3 beakers A strip of magnesium Kettle Metric ruler
4 test tubes Sciccors Ice
Test tube rack Thermometer 4 different M HCl (0.5, 1.0, 3.0, 6.0)
Procedure:
Part 1 Effect of Concentration on Reaction Rate
Obtain a piece of magnesium from teather. You will need a total of 9 pieces of magnesium that are each 1 cm long. Using the metric ruler and scissors, carefully cut 9 pieces from the large strip of magnesium. It is important that each piece be exactly the same length so that the amount of magnesium does not change in each of the reaction. Divide the mass of the large strip by 9 to get the average mass of each 1 cm piece. Record this value on a separate sheet of paper.
Label 4 test tubes with the appropriate concentration of acid to be added (0.5M, 1.0M, 3.0M, 6.0M)
Carefully measure 20 mL of each of the concentration of acid and place in the appropriate test tube.
Starting with the lowest concentration first (0.5M), place the 1 cm piece of magnesium in the test tube containing the acid. Begin timing as soon as the magnesium comes into contact with the acid. Record down the time it takes for all the magnesium to react.
Repeat procedure 4 with each of the concentration of acid. Calculate the average reaction rate by determining the grams of magnesium used per second. Record these values in the table.
Part 2 Effect of Temperature on Reaction Rate
Label 3 250mL beakers A, B and C. Add about 150mL of boiling water to beaker A. You will want water that is approximately 50˙c. In beaker B, you will have 150 mL of room temperature water. Record the exact temperature in your notebook. In beaker X, you will have 150 mL of ice and water that is approximately 0˙c.
Place 10 mL of 1.0M HCl into each of three test tubes. Place one of the test tubes into each of the beaker’s so that the acid will reach the temperature of the water in the beaker. Use the thermometer to check that the temperatures of the acids in the test tubes match those of the water naths. Do not proceed until they match.
Measure and record in your notebook the temperature of each test tube. Them, as in Part 1, place a 1 cm magnesium strip in each of the test tubes, and record down the amount of time necessary for the reaction go to completion.
Observation/data:
Table 1: Reaction rate vs concentration
Concentration of acid
Reaction time (s)
Reaction rate (g/s)
0.5M
276s
5.25x10-5g/s
1.0M
141s
9.93x10-5g/s
3.0M
17s
8.53x10-4g/s
6.0M
15s
9.76x10-4g/s
Table 2: Reaction rate vs temperature
Temperature
Reaction time (s)
Reaction rate (g/s)
50˙c
13s
1.11x10-3g/s
20˙c
51s
2.84x10-4g/s
0˙c
312s
4.65x10-5g/s
Question:
a) As concentration increases, reaction rate increases.
b) As temperature increases, reaction rate increases.
Doubling the concentration of HCl double the reaction