Question

What is observed when:
i) Potassium iodide is added to aqueous lead nitrate?
ii) Identify the type of reaction.
iii) Give a balanced chemical equation for this.

Answer 1

As we know that in chemistry, equations play a major role. In the reaction three things are main. There are reactant, product and reaction conditions. The reactants are always on the left side of the equation. If more than one reactant in the equation means by using plus sign. The products are always on the right side of the reaction. Something here also follows. More than one product by using plus sign. In between reactant products are used arrows to find the reaction direction in the equation.

Complete answer:
i) Potassium iodide is added to aqueous lead nitrate?
Potassium iodide is added to aqueous lead nitrate to give the product of lead iodide and potassium nitrate.
$2KI + Pb{\left( {N{O_3}} \right)_2} \to 2PbI + 2K\left( {N{O_3}} \right)$
ii) Identify the type of reaction.
The above reaction is a double displacement reaction, because two anions are replaced. The other name is called precipitation reaction. Because one of the products is precipitate.
iii) Give a balanced chemical equation for this.
The balanced chemical equation wise we can predict unknown products in the chemical reaction.
In chemistry, balances the chemical equation means,
We adjust the number moles of reactant and product used to attain an equal number of the same atom in reactant and product in the given chemical reaction.
The given chemical reaction is,
$2KI + Pb{\left( {N{O_3}} \right)_2} \to 2PbI + 2K\left( {N{O_3}} \right)$
All the elements in the above chemical reaction are equal in the product and reaction side of the reaction. Hence, the above reaction is called a balanced chemical reaction.

Note:
We need to know that in balanced chemical reaction wise, we predict the side product of the reaction. In some cases we are not able to attain balance by changing the mole. In that case we use the number of countable ions in the product and reactant side of the chemical reaction. In chemistry, redox reaction is one of the types of major reactions. In this redox reaction two methods are used to attain the balanced chemical reaction. There are ion-electron methods and the oxidation number method.