# Instructor`s Copy

```Instructor’s Copy
Lab Worksheet – Speed It Up
Table 1: Effect of Concentration on Rate of Reaction
Concentration of HCl
Time for complete reaction (seconds)
3M HCl
Should be faster.
1M HCl
Should be slower.
Table 2: Effect of Temperature on Rate of Reaction
Temperature of HCl
Time for complete reaction (seconds)
Hot
Should be fastest.
Cold
Should be slowest.
Room-temperature
Should be medium.
Data Questions:
1. One trial is not really going to give us accurate data. What could we have done in this lab to
improve the accuracy of our data?
Do more trials.
2. What effect does concentration of the acid have on the rate of the reaction of HCl and Mg?
The higher the concentration, the faster the reaction.
3. What is the effect of the temperature of the acid on the reaction rate of HCl and Mg?
The higher the temperature, the faster the reaction.
4. Write the balanced equation for the reaction between HCl and Mg.
2 HCl + Mg  MgCl2 + H2
5. What would increasing the surface area of magnesium, for example using many small pieces
instead of 1 large piece, do to the reaction rate?
It would react faster because more of the magnesium is in contact with the acid.
Conclusion:
The purpose of this experiment was to observe the effect of concentration and
temperature on the rate of reaction. Two other factors that effect the rate of a reaction
are surface area and catalysts. Increasing the surface area will increase the contact between the
reactants and will increase the rate of the reaction. Increasing the concentration
increases the rate of reaction. A catalyst is a substance that changes the rate of the reaction without
being changed itself. In general, when we increase the contact between the particles, we
increase the rate of the reaction. Conversely, if we need to slow down the rate of a reaction, we
should decrease the contact between the particles.
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