Question

Identify the type of reaction taking place in each of following cases and write the balanced chemical equation for the reactions:
(A). Zinc reacts with silver nitrate to produce zinc nitrate and silver.
(B). Potassium iodide reacts with lead nitrate to produce potassium nitrate and lead iodide.

Answer 1

Hint:
The reaction in which reactive metal displace less reactive metal is known as displacement reaction and the reaction in which group of reactants get interchanged are known as double-displacement reactions.


Complete step by step answer:
 Let us firstly discuss all the compounds given.
(A). Silver Nitrate: it is an inorganic compound with chemical formula $AgN{O_3}$ .It can be prepared by reacting silver with nitric acid. The by-products of the reaction depend upon the concentration of the nitric acid.
$3Ag + 4HN{O_3} \to AgN{O_3} + 2{H_2}O + NO$
$Ag + 2HN{O_3} \to AgN{O_3} + {H_2}O + N{O_2}$
$AgN{O_3}$ is used in organic synthesis and is also used in medicines.
(B). Zinc Nitrate: It is also an inorganic compound with chemical formula $Zn{(N{O_3})_2}$. It is with the chemical formula $Zn{(N{O_3})_2}$. It is a white, crystalline solid and is encountered as a hexahydrate $Zn{\left( {N{O_3}} \right)_2}.6{H_2}O.$ It is soluble in both alcohol and water.
(C). Potassium Iodide: It is a chemical compound with a chemical formula KI. Potassium iodide is used in formation of silver iodide $\left( {AgI} \right)$ which is an important chemical in film photography, KI is also used as a disinfectant and is a chemical for hair treatment. Potassium iodide is one of the main components in the electrolyte of dye sensitized solar calls (DSSC) along with iodine.
(D). Lead nitrate: Lead nitrate is also an inorganic compound with chemical formula $Pb{\left( {N{O_3}} \right)_2}$. It is a colourless are white powder. It is soluble in water. Lead nitrate is used as a heat stabilizer in nylon and polyester.
(a) Zinc reacts with silver nitrate to produce zinc nitrate and silver. This reaction is a type of reaction, more reactive displaces less reactive one. So, $Ag$ is displaced from $AgN{O_3}$ to give zinc nitrate.
$Zn + 2AgN{O_3} \to Zn{(N{O_3})_2} + 2Ag$
(b) Potassium Iodide reacts with lead nitrate to produce potassium nitrate and lead iodide. This is a type of double displacement reaction. The balanced chemical reaction is:- $2KI + Pb{\left( {N{O_3}} \right)_2} \to 2KN{O_3} + Pb{I_2}$

Additional information:
-Hydrogen atom is the simplest atom that has one proton and one electron. When an electron moves from one energy level to another energy level, then the energy of the electron also changes. Energy is required by the electron to move from one state to another.
-Ionization energy is defined as the amount of energy required to remove an electron from an isolated atom or molecule. Ionization energy is expressed in Joules or electron volt $(eV)$

Note: In the first reaction, oxidation of zinc takes place as its oxidation number change from $0{\text{ to + 2}}$ whereas the $Ag$ (silver) undergo reduction as it oxidation number changer from$ + 1{\text{ to 0}}$. The redox reactions are identified by examining the oxidation states of the compounds before and after reaction. The increase in oxidation state leads to oxidation whereas the decrease in oxidation state leads to reduction.