Reaction of Metals with Dilute Acids

Introduction    Metals vary considerably in their reactivity.  Some metals react with water at room temperature.  Other metals with hot water or steam.  Many metals do not react with water at all.  Will metals that are unreactive with water react with dilute acids?  Does a given metal react the same way with all dilute acids?  This experiment compares the reactions of various metals in three different dilute acids.  By observing their behaviour, you will be able to rank the metals according to their reactivity.

PROBLEM    How do the reactions of various metals in dilute acids compare?

APPARATUS    5 (18 x 150 mm) test tubes        test tube rack
                           Bunsen burner

MATERIALS        aluminum foil       calcium turnings
                               copper foil           magnesium ribbon
                               'mossy' zinc         1 mol/L hydrochloric acid
                               wooden splints      1 mol/L acetic acid
                                                          1 mol /L sulphuric acid

PROCEDURE

  1. 1.  Prepare a copy of the data table to record your observations.
Metals Reaction with Hydrochloric Acid Reaction with Sulphuric Acid Reactions with Acetic Acid
Aluminum
Calcium
Copper
Magnesium
Zinc
  1. 2.  In 5 separate test tubes, place i) a 2 cm strip of aluminum foil ii) a small piece of calcium  iii) a 2 cm strip of copper foil  iv) a 2 cm strip of magnesium ribbon and v) a small piece of 'mossy' zinc.
  2. 3.  Add 5 mL of dilute hydrochloric acid to each of the test tubes and note the reactions.
  3. 4.  If a gas is produced, hold your thumb over the mouth of the test tube until you feel the pressure build up.  Release you thumb immediately bring a burning splint to the mouth of the test tube.
  4. 5.  Repeat Procedures 2, 3 and 4 using dilute sulphuric acid, and then dilute acetic acid in place of the hydrochloric acid.
QUESTIONS

a)  Did all of the metals tested react with dilute hydrochloric acid?  Rank the metals in order of their reactivity.
b)  In reactions that produced a gas, was the same gas formed in each case?  Identify the gas.  Where did the gas come from?
c)  Compare the reactivity of each metal in the three different acids.  Is there any difference in the vigor of the reactions in the different acids?  Do you notice any pattern?
d)  Compare the order of reactivity of the metals in each of the acids.  Did you rank the metals in the same order with each acid?
e)  When metals react with acids, two products are produced.  One is a gas and the other is a salt.  Write a general word equation for the reaction of a metal with an acid.  Include the name of the gas produced.

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