Respuesta :
That would be the first option Ca(OH)2 + H2SO4 → CaSO4 + 2H2O.
The Ca replaces the H2 in H2SO4, and the H2 replaces the Ca is Ca(OH)2.
Answer: Option (a) is the correct answer.
Explanation:
A chemical reaction in which there occurs exchange of two ions between two different compounds is known as a double replacement reaction.
For example, [tex]Ca(OH)_{2} + H_{2}SO_{4} \rightarrow CaSO_{4} + 2H_{2}O[/tex]
Here, [tex]OH^{-}[/tex] ions of [tex]CaOH_{2}[/tex] is replaced by [tex]SO^{21}_{4}[/tex] ions of sulfuric acid and [tex]SO_{4}[/tex] of sulfuric acid is replaced by [tex]OH^{-}[/tex] ions of [tex]CaOH_{2}[/tex].
When two atoms combine together to form a compound then it is known as synthesis reaction.
When a compound reacts with oxygen to give carbondioxide and water then it is known as combustion reaction.
When a metal is treated with an acid to yield hydrogen gas then it is known as single replacement reaction.
Therefore, we can conclude that [tex]Ca(OH)_{2} + H_{2}SO_{4} \rightarrow CaSO_{4} + 2H_{2}O[/tex] is a double replacement reaction.
