Topic: The relationship between the rate of reaction and
surrounding temperature in the reaction between HCl and
Mg
2. Exploration
2.1 Background information
Magnesium can have reaction with hydrochloric acid which produces magnesium chloride as
well as the hydrogen gases. According to the chemical equation, we can find one unit of Mg
reacts with two units of HCl can produce one unit amount of MgCl2 and one unit amount of
H2 . The phenomenon of this reaction is that the solid magnesium solves which allows the
solution to be colorless, meanwhile, it releases the heat there as an exothermic reaction. As
Van’t Hoff’s equation has mentioned that as the temperature rises up by 10K, the chemical
reaction’s will be faster as 2-4 times.
RQ:How does the surrounding temperature(25℃/50℃/75℃/100℃)
affect the rate of reaction(measured by the volume of H2 released
in 2mins ) for HCl and Mg?
2.2 Variables
Kinds of variables Name of variables Measure to vary or control
Independent variable The surrounding temperature When it is reacting, use the burner to
give heat to the reaction beaker,
controlling the temperature by
25,50,75,100 centigrade. water bath
Dependent variable the volume of H2 in 2 mins The changing in the temperature
which leading to the changing of the
rate of reaction
Control variable Pressure Pressure is approximately constant
because all of the trials are done
under the same condition
Control variable The amount of HCl and Mg Use the electronic balanced to
measure the certain mass of HCl and
Mg each time
Table 2
Type of variables Range/Quantity Units Method of controlling
Independent 25℃/50℃/75℃/100℃ C° Use the thermometer to
monitor the temperature
when heating the reaction
in the beaker
Dependent % error of measured rate of
the certain reaction
Mol/s Monitor the loss of the
mass from time to time
and make the function
of that rate there
Controlled Pressure kPa Use the pressure sensor
to receive the data of the
pressure
time s 120s
Controlled The amount of HCl and Mg g The electronic balanced
to measure the mass of
these two species
2.apparatus:
measuring cylinder 1000ml
conical flask 250ml
volumetric flask 250 ml
electronic balance
2.3 Procedures
1. Use the beaker to carry enough HCl.
2. Use the electronic balanced to find the mass of HCl.
3. Put the Mg onto the electronic balanced and measure the mass of the Mg.
4. Heat the HCl to 25, 50, 75, 100℃ respectively.
5. Topple the Mg into the beaker of HCl.
6. Record the data if the mass of the whole system per 5 seconds.
7. Repeat 2-3 steps for twice.
8. Repeat steps 1-7 with the different temperature for 3 times.
2.4 Safety Concern
Since the HCl solution is such a kind of acid which cannot be touched directly, we need to be
careful when we pour the HCl solution. By that reason, we need to wear the lab’s clothes and
the gloves to make sure the safety. The beaker may be too hot after heating, making sure not
to be scalded.