Which of the following is a weak electrolyte ?

Which one of the following is a weak electrolyte?

Which one of the following is a weak electrolyte? NaCl, CH_3 – COOH, HCl)

What is weak electrolyte?

State which of the following solutions are weak electrolytes - dil. HCI , carbonic acid , NH_(4) OH, dil.H_(2) SO_(4) , AGNO_(3) , Na_(2)CO_(3), PbBr_(2), KOH, HI , oxalic acid , NAHCO_(3) , sodium acetate , Na_(2) SO_(4) , NaOH

Which of the following statements are correct for van't Hoff factor 'i' for a solution of weak electrolyte A_(x)B_(y) ?