Question

Which of the following is a weak electrolyte?
A. \[N{a_2}C{O_3}\]
B. \[KHC{O_3}\]
C. \[{(C{H_3}COO)_2}Pb\]
D.All of the above

Answer 1

Hint: To solve this question, we must understand the meaning and characteristics of a weak electrolyte. Then we need to compare the properties of the compounds given to us to find the correct answer.

Complete Step-by-Step Answer:
Before we move forward with the solution of the given question, let us first understand some important basic concepts.
Weak electrolytes can be basically defined as those compounds which do not completely dissociate in aqueous solutions. To put this in simpler terms, we can say that weak electrolytes are those compounds which partly or very negligibly dissociate into their constituent ions, when they are mixed in aqueous solutions. These compounds only partially ionize in water.
Let us now discuss the options given to us:
A. \[N{a_2}C{O_3}\] : The molecular formula of \[N{a_2}C{O_3}\] or sodium carbonate is 106 g/mol. When measured at STP, only 34 g of sodium carbonate dissolves in water. This means that one mole of sodium carbonate cannot fully dissociate into one mole of water. Hence, it is a weak electrolyte.
B. \[KHC{O_3}\] : The molecular formula of \[KHC{O_3}\] or potassium bicarbonate is 100.115 g/mol. When measured at STP, only 22.4 g of potassium bicarbonate dissolves in water. This means that one mole of potassium bicarbonate cannot fully dissociate into one mole of water. Hence, it is a weak electrolyte.
C. \[{(C{H_3}COO)_2}Pb\] : The molecular formula of \[{(C{H_3}COO)_2}Pb\] or lead diacetate is 235.29 g/mol. When measured at STP, only 69.5 g of sodium carbonate dissolves in water. This means that one mole of lead diacetate cannot fully dissociate into one mole of water. Hence, it is a weak electrolyte.

Hence, Option D is the correct option

Note: On the other hand, a strong electrolyte is a solution/solute that completely, or almost completely, ionizes or dissociates in a solution. These ions are good conductors of electric current in the solution.