Question

#1: Here is the overall reaction of a mercury oxide dry cell: Zn + HgO --> ZnO + Hg. In this reaction, which of the following gets oxidized?

A. Hg

B. O

C. Zn

D. HgO

**not too sure.. i think it's either A or C.. what do u think @thomaster :)

Answer 1

#2: In which of the following combinations would you need an electroplating apparatus to coat the first metal onto the second metal?

**see table attached!**

A. aluminum onto lead (Pb)

B. cadmium onto nickel

C. tin (Sn) onto copper

D. nickel onto iron

**my answer; D

is that right? :)

Answer 2

#3: In an electroplating apparatus, where does the oxidation reaction occur?

A. on the surface of the cathode

B. on the surface of the anode

C. in the solution

D. on the surface of the battery

***my answer; B

not 100% sure though.. what do u think? is that right? :)

Answer 3

#4: Of the metals K, Fe, H, and Mg, which will spontaneously donate electrons to sodium (Na)?

***see table attached!! btw, they're the same tables haha just attached again to make it easier to see :) ***

A. K

B. Fe

C. H

D. Mg

**my answer: B. Fe

not too sure tho.. what do u think? :)

Answer 4

#1
\(Hg^{2+} + 2e^- \rightarrow + Hg\)
\(Zn \rightarrow Zn^{ 2+} + 2 e^-\)

So mercury gets reduced

Answer 5

#5: Which of the following statements is true about a nickel-cadmium dry cell?

A. The cathode reaction is Cd + 2OH- --> Cd(OH)2 + 2e-.

B. The cathode reaction is NiO2 + H2O + 2e- --> Ni(OH)2 + 2OH-.

C. The cathode reaction is Cd + NiO2 + 2H2O --> Cd(OH)2 + Ni(OH)2.

D. The anode reaction is NiO2 + H2O + 2e- --> Ni(OH)2 + 2OH-.

***not too sure... i think its either B or D.. but I'm not sure whether its the cathode reaction or anode.. what do you think? :)

Answer 6

okay, so #1 is A. Hg then? :)

Answer 7

yes

Answer 8

okay! awesome :) what do you think of the others? :D

Answer 9

#2
Iron is higher than nickel in the list so D

Answer 10

kk :)

Answer 11

what do u think of #3? =)

Answer 12

#3
ew i made a mistake XD electrolating: reduction is at the surface of the cathode, not anode (this was #5 in your previous post)
Oxidation is at the surface of the anode

Answer 13

so #5 on the previous one was D, surface of CATHODE ?

Answer 14

yes :P

Answer 15

okay! awesome :)

so what would #3 be here? :D

Answer 16

would #3 be B. on the surface of the anode?? cuz its oxidation?

Answer 17

yea i just told you that :P

Answer 18

haha kk :) sorry! :D

what about 4 and 5? :D

Answer 19

hey @abb0t :)

Answer 20

Too many questions thrown all at once.

Answer 21

oh oops... sorry!

Answer 22

i think #4 is hydrogen, not 100% sure tho
#5
cadmium electrode is the cathode
at this electrode reaction A occurs
B is the anode reaction

So i think A

Answer 23

okay.. so 5 is this?

A. The cathode reaction is Cd + 2OH- --> Cd(OH)2 + 2e-.

and 4 is this? C. H ??

:O

Answer 24

lol i totally did something completely wrong for #5 :/ oops! but i see what you mean now.. cathode it is :)

Answer 25

thank you :)

Answer 26

Based on the given chart, hydrogen would be the correct answer.

Answer 27

okay! thanks for confirming! :D