Question

REDOX

Which one of the following is a redox reaction?
2 Na(g) + Cl2(g) 2 NaCl(s)

K2Cr2O7(aq) + 2 KOH(aq) 2 K2CrO4(aq) + H2O(l)

H2O(l) H+(aq) + OH -(aq)

Na2CO3(s) + 2 HCl(aq) 2 NaCl(aq) + CO2(g) + H2O(l)

Ba2+(aq) + SO42-(aq) BaSO4(s)

The answer is the first but take me step by step.

Answer 1

@iPwnBunnies

Answer 2

yepp ill look at Khan but ya heres something better to explain

Answer 3

I can barely teach precipitation reactions, I'll barely be a help on redox reactions.

Answer 4

Check out some lessons on redox reactions. I need help with these when I first learned them, I found great videos online that explained them.

Answer 5

needed*

Answer 6

bro. I know how to find their charges and stuff. I knwo this. but I dont know if it's a redox if the charge changes or what.

Answer 7

The oxidation numbers are the biggest thing to worry about. Well, first you need to know at least something about a redox reaction.

Answer 8

i know what Reducing agent and oxidizing agent are and that stuff. for a redox, is it when the charge changes in one of the elements or stays the same?

Answer 9

When the oxidation # of a substance increases from the reactant side to the product side, the substance is oxidized and loses electrons.

Answer 10

Another thing to think about, can you cancel any of the choices out?

Answer 11

Honestly, I'm not the guy that can explain this that well.

Answer 12

ok ohhhhh i have one that you may be able to solve!

you good with oxidation numbers?

Answer 13

Barely.

Answer 14

Like, I know the answer to the question b/c I know one of the polyatomic ions in one of the answer is a pretty good oxidizer.

Answer 15

Give the oxidation number of nitrogen in each of the following
NH4+

ok so I know it's suppose to be balanced. but the answer is -3. I got -4 because H is +1 and 4 x 1= 4. but idk why it's -3. do you know?

Answer 16

Yes, because when it comes to numbers, a polyatomic ion's oxidation number is the same as their charge.

Answer 17

Ammonium, NH4+, has a charge of 1+, so its O# is also 1.

Answer 18

H has an O# of +1, and there's 4 of em like you noted, so the total H O# is 4+.
O# of N will be +1 - 4 = -3

Answer 19

OHHHHH so that + says that it's a charge of positive 1 so basically it goes with the H and cancels one out?

Answer 20

wait i worded that bad

Answer 21

so N has a charge of -4? i thought it had a -3 charge.


waiittt so if it's just a postive charge. then it means just one? so whatver N equals, it's that charge?

Answer 22

Oxidation numbers and ion charges don't have a connection. Ion charges exist, but oxidation numbers are made up to help us with redox reactions.

Answer 23

Nitrogen usually has a -3 charge in ionic bonds.

Answer 24

ah ok then

Answer 25

I don't think you looked at this question right lol.
O# of N + 4(O# of H) = -1

Answer 26

Nitrogen doesn't have a -4 charge or a -4 O# in the ion. I used 1-4 because I was the subtracting the O# of the Hydrogen from the total O#.

Answer 27

but howd you know the total?

Answer 28

I mentioned it above. Ammonium, NH4+, is a polyatomic ion with a +1 charge. Polyatomic ions also have O#s that are the same as their ion charge. So, NH4+ has an O# of 1.

Answer 29

okk thanks!