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Aim of this experiment to study the reaction between zinc and dilute sulphuric acid.
Zinc metal reacts with dilute sulphuric acid to produce zinc sulphate and hydrogen gas. The metal displaces Hydrogen from the acid and forms a salt.
The chemical equation can be written as:
This reaction is an example of a single displacement reaction. Metals with high reactivity, such as magnesium, aluminium, iron, etc., undergo such reactions, whereas metals with low reactivity, such as gold, silver, copper, etc., do not liberate hydrogen gas with dilute acids.
The evolved hydrogen gas is neutral and does not possess any characteristic colour or odour. When this gas undergoes combustion with the oxygen present in the atmosphere, water vapour is formed.
Apparatus and materials required are:
Apparatus
- Test tube
- Spatula
- Red and blue litmus papers
- Rubber cork fitted with glass tube
- Lighter
- Candle
- Distilled water in a small beaker
Chemicals
- Zinc granules
- Dilute sulphuric acid
Procedure:
- Add 10 mL of dilute sulphuric acid to a test tube containing a few granules of zinc metal.
- Fit a rubber cork with a glass tube into the mouth of the test tube.
- Observe the colour and the odour of the gas evolved in the reaction mixture.
- Bring a lit candle near the opening of the glass tube in the mouth of the test tube.
- Observe the colour of the flame.
Here we conclude that
Zinc being one of the most reactive metals readily reacts with dilute sulphuric acid to form zinc sulphate and hydrogen gas. Aqueous zinc sulphate thus formed is colourless.
The properties of hydrogen gas were studied and it can be concluded that:
- Hydrogen is a colourless gas.
- Hydrogen gas is odourless.
- Hydrogen is neutral in nature.
- Hydrogen is a highly combustible substance.
FAQs on Study Reaction of Zinc With Sulphuric Acid
Q1: When a lighter was brought near the hydrogen gas, it burnt with a pop sound. What can you infer from this?
Answer: Hydrogen gas undergoes combustion reaction in the presence of atmospheric oxygen and this can be heard as a squeaky ‘pop’ sound.
Q2. What is a balanced chemical equation?
Answer: In a chemical equation, the reactants and products side must balance the number of each atom for every element. For a balanced chemical equation, the mass and the charges for both sides of the reaction must be equal. A chemical reaction always obeys the law of conservation of mass.
Q3: What is the balanced equation for the reaction between zinc and sulfuric acid?
Answer: The balanced equation is:
Zn(s) + H2SO4(l) → ZnSO4(aq) + H2 (g)
Q4: Which element is getting oxidised in the given reaction?
Zn(s) + H2SO4(l) → ZnSO4 (aq) + H2 (g)
Answer: Zinc is getting oxidised from +0 to +2.
Q5: What is the oxidation state of sulphur in zinc sulphate?
Answer: The oxidation state of sulphur in zinc sulphate is +6.
Let Sulphur is x, Zinc oxidation state +2, oxygen oxidation number -2
+2 + x + 4(-2) = 0
x = +6
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