Question

To perform and observe the action of water on quicklime

Answer 1

$\underline\mathfrak{Aim}$

To perform and observe the action of water on quicklime and classify the reaction.

$\underline\mathfrak{material \: required}$

• Calcium oxide,water, beaker, glass rod, dropper, red litmus paper, test tube, filter paper, funnel.

$\underline\mathfrak{theory}$

• Quicklime reacts with water to form calcium hydroxide. As in this reaction two substances – quicklime and water combine to form a new substance, therefore, this reaction is called combination reaction. This chemical change can be represented by the given chemical equation:

$\underline\mathfrak{procedure}$

1. Wash a borosil beaker with distilled water and dry it.
2. Take a small amount of calcium oxide (quick lime) and slowly add water to it.
3. Wash and take a clean glass rod to stir the mixture of quick lime and water.
4. Touch the beaker carefully from outside.
5. Observe the change.
6. With the help of dropper take a few drops of the mixture from the beaker and place it on red and blue litmus paper strips.
7. Wait and observe.

$\underline\mathfrak{Observation}$

• A hissing sound is heard during the reaction when water is added to the beaker containing quick lime. Due to the evolution of heat during the reaction the temperature increases and makes the solution hot.
• Solution on litmus paper Drops on the red litmus paper strip change the colour of the paper to blue whereas there is no colour change observed on the blue litmus paper.

$\underline\mathfrak{Result \: and \: conclusion}$

• From the above experiment we can conclude that the reaction occurred between calcium oxide (Quick lime) and water combine to produce one single product slaked lime (Ca(OH)2) is called combination reaction as well as an exothermic reaction.
• Two compounds, viz. quicklime and water combine to form calcium hydroxide. Therefore, this reaction is an example of combination reaction.

$\underline\mathfrak{ precautions }$

• Quicklime can cause severe burns, therefore, it should be handled with spatula.
• As the reaction between quicklime and water is exothermic, water should be poured over quicklime slowly.
• The filtrate collected should be clear.

Answer 2

Answer:

Same as the above reaction