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A pure, white crystalline solid dissolves in water to yield a basicsolution that

ID: 690780 • Letter: A

Question

A pure, white crystalline solid dissolves in water to yield a basicsolution that liberates a gas when excess acid is added to it. Onthe basis of this information, the solid could be A) KNO3 B) K2CO3 C) KOH D) KHSO4 E) KCl
I know the answer is B but can you explain why thatis correct and the other are incorrect? A) KNO3 B) K2CO3 C) KOH D) KHSO4 E) KCl
I know the answer is B but can you explain why thatis correct and the other are incorrect? E) KCl
I know the answer is B but can you explain why thatis correct and the other are incorrect?

Explanation / Answer

Ok. When I look at all of these compounds I notice they areall strong electrolytes. So once they are in solution they willbecome free ions and can react easily with other compounds.NO3 , Cl , and HSO4 are all parts of strongacids so with excess acid they will gain H+ ionsbecoming strong acids. (HNO3 , HCl ,H2SO4). KOH is a strong base so it will justslowely become H2O + acid. TheCO32- is special. CO32- + H2O <-->HCO31- + OH1- (This is whathappens is solution) HCO31- + H+ -->H2CO3 <--> H2O +CO2 (gas) (This is the reaction in excess acid) Hope this helped