Answer : The correct answer is D. NH₃
Weak electrolytes :
These are electrolytes which do not completely ionize in aqueous solution . They undergo partial ionization (generally 1% - 10% ) unlike strong electrolytes 100% .
Generally weak acid and weak bases are weak electrolytes . They have low solubility in aqueous solutions . Example : CH₃COOH , NH₃ etc.
Checking all the options :
A ) NaBr :
NaBr is made of Na which is a metal and Br is non metal . Metal and non metal forms an ionic compound . Ionic compound have high solubility in aqueous solutions , They completely dissolves to give their ions ,
Hence NaBr is not a weak electrolyte .
B) HBr :
HBr is strong acid ( Given in image attached ) . Also it is an ionic compound . Hence it is not an weak electrolyte .
C) KOH :
KOH is again an ionic compound which has ions K⁺ and OH⁻ . Also It is strong base ,( given in image attached ) . Hence it is not an weak electrolyte.
D) NH₃ :
NH₃ is made of N and H , both are non metals . Two or more non metals form a covalent compound . Covalent compound do not produce ions and they have low solubility in aqueous solutions .
Hence it will not dissolve in aqueous solutions . So NH₃ is a WEAK ELECTROLYTE.
Hence D) NH₃ is a weak electrolyte.
