Which of the following aqueous solutions would test closet to pH 7

[JessicaHelena]

Homework Statement

>Which of the following aqueous solutions would test closet to 7 on the pH scale?
$a) NaCl$, $b) Na_2CO_3$, $c) NaH_2PO_4$, $d) NaCN$

Homework Equations

The Attempt at a Solution

I don't understand this. So I tried writing chemical equations like for a), NaCl + H20 --> NaOH + HCl, and so on. But for example, HCl (the product in the previous equation) is a strong acid, so I thought it'd have a low pH, but apparently a) is actually the answer, and I don't know how to get that.

 

[BvU]

Perhaps you need a relevant equation ? Any candidates ?

 

[Borek]

Do the names Brønsted-Lowry ring a bell?

 

[JessicaHelena]

@Borek — yes, kind of, it was about acids and bases definition, I think.

 

[Borek]

OK, so try to apply this definition and see what are possible reactions of the substances listed.

 

[Ygggdrasil]

I don't understand this. So I tried writing chemical equations like for a), NaCl + H20 --> NaOH + HCl, and so on. But for example, HCl (the product in the previous equation) is a strong acid, so I thought it'd have a low pH, but apparently a) is actually the answer, and I don't know how to get that.

You are correct that HCl is a strong acid. Do you know what the definition of a strong acid is? Do you know what the definition of a weak acid is?

 

[HAYAO]

Do you understand the dissociation constant? Knowing this constant for the acids/bases can help you.