Question

1.) Match each of the substances with the expected pH of the resulting solution when they are added to neutral water. Determine if acidic, basic, or neutral.
HI
Cr(NO3)3
LiOH
KBr
NaF

2.)Which of the following pairs contains a conjugate acid-base pair?
Perchloric acid and chloric acid.
Hydrochloric acid and sodium hydroxide.
Sodium cyanide and hydrocyanic acid.
Sodium bromide and bromous acid.

Answer 1

@Cuanchi

Answer 2

@Photon336

Answer 3

Well for H-I let's say if we added that to water what do you think would be the result?

Answer 4

@staldk3

Answer 5

HI + H2O --> (H3O+) + I-

Answer 6

yeah remember HI is an acid and in fact a good one. the iodine ion is actually stable because of it's large size. so it's going to be an acid.

we know right away that LIOH will be basic. when added to water.

KBr won't really do much to the pH

Answer 7

what about NaF what do you think would happen if it were added to water?

Answer 8

NaF + H2O --> NaOH- + HF

Answer 9

almost

Flourine wants to take that proton so badly it will remove protons from water, generating OH- ions.

\[NaF + H_{2}O \rightarrow HF + Na^{+} + OH^{-}\]

Answer 10

Take a look at this reaction:

\[Cr(NO3)3 + 3H2O → Cr(OH)3 + 3HNO3\]

Answer 11

Would the Cr(NO303 make is neutral?

Answer 12

yeah I would think so you get cromium hydroxide and nitric acid.

Answer 13

So with the NaF would it make it basic?

Answer 14

yep

Answer 15

I knew I was right but for some reason it's counting it wrong. Anyway what about the 2nd one?

Answer 16

@Photon336 Which of the following pairs contains a conjugate acid-base pair? Perchloric acid and chloric acid. Hydrochloric acid and sodium hydroxide. Sodium cyanide and hydrocyanic acid. Sodium bromide and bromous acid.

Answer 17

conjugate acid base pair. to find these it's easy. they differ in the presence of one hydrogen that's it.they are the same compounds just one has an extra hydrogen the other one does not.

Answer 18

So it would be one of the last two on the list.

Answer 19

Since the first one is acid and the second one is a strong acid and base?

Answer 20

so can you write out the compounds in each pair?

Answer 21

Sodium cyanide and hydrocyanic acid. NaCN + HCN --> Na + H +C2N2 (unsure on this one.)
Sodium bromide and bromous acid. NaBr + HBrO2--> NaOH + Br2O

Answer 22

Do those seem right?

Answer 23

@Photon336 what do you think on the first one?

Answer 24

@satellite73

Answer 25

@Compassionate