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प्रश्न
Give a scientific reason.
When the gas formed on heating limestone is passed through freshly prepared lime water, the lime water turns milky.
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उत्तर
- When limestone is heated, calcium oxide and carbon dioxide gas are formed.
\[\ce{\underset{\text{carbonate}}{\underset{\text{Calcium}}{CaCO_{3(s)}}} + Heat -> \underset{\text{oxide}}{\underset{\text{Calcium}}{CaO_{(s)}}} + \underset{\text{dioxide}}{\underset{\text{Carbon}}{CO2\uparrow}}}\] - When carbon dioxide gas is passed through freshly prepared lime water, the solution turns milky due to the formation of calcium carbonate, which is insoluble in water.
\[\ce{\underset{\text{hydroxide}}{\underset{\text{Calcium}}{Ca(OH)2_{(aq)}}} + \underset{\text{dioxide}}{\underset{\text{Carbon}}{CO_{2(g)}}} -> \underset{\text{carbonate}}{\underset{\text{Calcium}}{CaCO_{3(s)}}} + \underset{\text{Water}}{H2O_{(l)}}}\]
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संबंधित प्रश्न
Why is the amount of gas collected in one of the test tubes in the following Activity double of the amount collected in the other? Name this gas.
- Take a plastic mug. Drill two holes at its base and fit rubber stoppers in these holes. Insert carbon electrodes in these rubber stoppers as shown in the following Fig.
- Connect these electrodes to a 6 volt battery.
- Fill the mug with water such that the electrodes are immersed. Add a few drops of dilute sulphuric acid to the water.
- Take two test tubes filled with water and invert them over the two carbon electrodes.
- Switch on the current and leave the apparatus undisturbed for some time.
- You will observe the formation of bubbles at both the electrodes. These bubbles displace water in the test tubes.
- Is the volume of the gas collected the same in both the test tubes?
• Once the test tubes are filled with the respective gases, remove them carefully. - Test these gases one by one by bringing a burning candle close to the mouth of the test tubes.
Caution: This step must be performed carefully by the teacher.
- What happens in each case?
- Which gas is present in each test tube?
Write the balanced chemical equation for the following and identify the type of reaction.
\[\ce{Zinc carbonate(s) -> Zinc oxide(s) + Carbon dioxide(g)}\]
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Write one equation for decomposition reactions where energy is supplied in the form of heat.
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(a) What is compound A?
(b) What is compound B?
(c) What is gas C?
(d) What do you think is the black substance X? What is its function?
(e) What is the general name of substances like X?
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What type of reaction is represented by the following equation?
2 FeSO4 → Fe2 O3 + SO2 + SO3
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When a green iron salt is heated strongly, its colour finally changes to brown and odour of burning sulphur is given out.
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(b) Name the type of reaction that takes place during the heating of iron salt.
(c) Write a chemical equation for the reaction involved.
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(a) Design an activity to demonstrate the decomposition reaction of lead nitrate.
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(c) Write balanced chemical equation for the reaction stating the physical state of the reactant and the products.
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Give a balanced equation for –
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Give a balanced equation for the following type of reaction:
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Explain the reaction given in the figure.
Electrolysis is type of ______ reaction.
Chemical volcano is an example of ______ type of reaction.
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Which of the following statement about the reaction is correct?
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The reaction of calcium carbonate, with freshly prepared lime water, is shown below:
Answer the questions with the help of a diagram:
- What type of reaction does calcium carbonate undergoes?
- What change in colour is observed in lime?
- Write the chemical equation.
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- Name the process that occurs. Why is it called so?
- Illustrate the reaction of the process with the help of a chemical equation.
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- Write the name and formula of the coloured gas liberated.
- Write the balanced chemical equation for the reaction.
- Name the residue left in the test tube and state the method of testing its nature (acidic/basic).
