Question

i need help with writing net ionic equations:

1A: Aqueous sodium nitrate and Fe2+ (aq) react in acidic solution forming Fe3+ (aq) and colorless, nitric oxide gas (NO(g)) gas.

1B. NItric oxide is immediately oxidized to the red-brown nitrogen dioxide gas by molecular oxygen in the air.

Answer 1

can you write the formulas of each species not shown? (e.g. sodium nitrate)

Answer 2

NaNo3,

Answer 3

okay, so you have NaNO3 and Fe2+ and you form Fe3+ and NO

NaNO3 + Fe^2+ -> Fe^3+ + NO

essentially, since it's "net ionic", you don't write anything that is not used.. like Na
and you write everything in ions

Na^+ + NO3^- + Fe^2+ -> Fe^3+ + NO

since Na+ is not used, you don't need to write it and you're left with:

NO3^- + Fe^2+ -> Fe^3+ + NO

Answer 4

Ok. thank you but I don't really get what oyu mean by not being used. Could you explain?

Answer 5

oh wait because of what the question asked? you mean thats why we don't use Na?

Answer 6

well Na+ (in this reaction) what we call a "spectator ion", meaning that it's not reacting.
And since it's not reacting, you don't need to write it hence "net equation"

Answer 7

so how would i got about part B?

Answer 8

the equation would normally be:

Na^+ + NO3^- + Fe^2+ -> Fe^3+ + NO + Na^+

since Na^+ is unchanged, you can cancel both out (or simply not write it)

Answer 9

okay so:

nitric oxide + oxygen gas -> nitrogen dioxide

can you write the formulas of those in place instead of the actual names?

Answer 10

btw do you have to balance them as well? because these are redox reactions

Answer 11

yeah I can do that. I kinda get it so like for NaNo2 disproportionating to NO and No3- it would be like

NO(g) + NO3-?

Answer 12

the instructions just say to write the net ionic equations. I'm curious though in order to get hte net ionic equation don't they have to be balance first

Answer 13

hm if you haven't learnt to balance redox reactions they wouldn't expect you to. I also think they would explicitly tell you to balance them.

"yeah I can do that. I kinda get it so like for NaNo2 disproportionating to NO and No3- it would be like

NO(g) + NO3-?"

is this referring to the first reaction?

Answer 14

no this is a new one here is the problem: aqueous sodium nitrite disproportionates to nitric oxide gas and aqeuous nitrate ion in warm acidic solution

Answer 15

yeah that's it

NO2^- -> NO3^- + NO

Answer 16

this one you can easily balance

Answer 17

ok and so aqueious sodium phosphate forming a white precipitate (Ba3(PO4)2 in aquous barium chloride would just be Ba + PO4?

Answer 18

yeah if there is a ppt you have to write it

also don't forget to write the charges on each ion because, after all, these are ionic equations

Answer 19

yeah i'm going to have to go look at the periodic table to figure them out haha. what do you mean if there is a precipitant write it

Answer 20

Ba + PO4 -> (Ba3(PO4)2 (s)


ps. i didn't write the charges

Answer 21

sorry too many brackets

Ba + PO4 -> Ba3(PO4)2 (s)

Answer 22

ohhhhh I got it thank you

Answer 23

awesome. no problem !

Answer 24

Ionic equations must always be balanced. You lose marks if you don't.

Answer 25

i definitely agree, although you can't balance,

"Aqueous sodium nitrate and Fe2+ (aq) react in acidic solution forming Fe3+ (aq) and colorless, nitric oxide gas (NO(g)) gas."

without knowing how to balance redox reactions because the oxygen and nitrogens are in weird ratios. So if they haven't learnt how to, it would be absurd for them to be expected to.