Question

Quicklime reacts vigorously with water to produce a product Y. Write the formula, chemical and general name of Y. Express this reaction in the form of a chemical equation. What type of a reaction is this?

Answer 1

Hint: Focus on the word ‘vigorous’ written in the question. It is an indication of the tendency of the reactants to react. It is a highly feasible reaction.

Complete step by step answer:
Quicklime, also known as burnt lime, is a white, caustic, alkaline, crystalline solid. Quicklime reacts vigorously with water to produce slaked lime. The reaction is as follow –
  \[CaO+{{H}_{2}}O \to Ca{{(OH)}_{2}}+\Delta H\]
where,
\[CaO\] is Quick lime – it is also called Calcium oxide or Oxocalcium
\[Ca{{(OH)}_{2}}\] is Slaked lime
\[{{H}_{2}}O\] is Water
\[\Delta H\] is Heat of enthalpy
As we can see, in this reaction energy is liberated or in simpler words, heat is released. Its product has a lower energy than the reactant. Therefore, this reaction is called an exothermic reaction, i.e. its heat of enthalpy \[(\Delta H)\] is negative.
Therefore, the answer is –
The compound Y is a compound with
formula – \[Ca{{(OH)}_{2}}\]
chemical name – calcium hydroxide
general name – slaked lime
And this is an exothermic reaction.

Additional Information:
Other than slaked lime, this compound is also known by other names, such as- hydrated lime, caustic lime, builders' lime, slack lime, cal, or pickling lime.

Note: Calcium oxide or quicklime can be produced by the decomposition of calcium carbonate, i.e. heating crushed limestone to around 1000 degree Celsius. Carbon dioxide is also produced as an end product in this reaction, but being a gas, it gets released. The reaction is given as follows –
\[CaC{{O}_{3}}(s)\xrightarrow{\Delta }CaO(s)+C{{O}_{2}}(g)\]
This is an endothermic reaction as heat is required in this reaction, therefore its enthalpy \[(\Delta H)\] is positive.