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Flashcards in module 2 - redox Deck (20)
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1
Q

in oxidation numbers, does the number or the sign come first?

A

the sign

2
Q

what’s the oxidation number of F in a compound?

A

-1

3
Q

what’s the oxidation number of H in metal hydrides? give examples of 2 metal hydrides!

A

> -1

> NaH, CaH2

4
Q

what’s the oxidation number of O in peroxides? Give an example of a peroxide?

A

> -1

> - H2O2

5
Q

what’s the oxidation number of O when it’s bonded to F?

A

+2 e.g. in F2O

6
Q

in a compound, what must the sum of the oxidation numbers be equal to?

A

the total charge

7
Q

say the 3 steps in working out oxidation numbers in a compound/ ion?

A

1) assign any ox numbers with rules
2) work out overall charge
3) work out unknown numbers based on that everything should add up to overall charge

8
Q

what are roman numerals used in, for redox?

A

used in names of compounds that have elements that form ions with different charges

9
Q

what does the roman numerals show?

A

the oxidation number (state) of the element with no sign

10
Q

what is the formula and ox number for iron(II)?

A

Fe 2+ so, ox = +2

11
Q

what are the modern names for nitrite and nitrate? what are these names based on?

A
  • nitrate (III)
  • nitrate (v)
  • the oxidation number of the nitrogen
12
Q

what is oxidation and reduction in terms of oxygen reactions?

A
  • addition or removal of oxygen
13
Q

in the reaction CuO + H2 —> Cu + H2O , whats been oxidised? and reduced?

A
  • hydrogen is oxidised by gaining oxygen

- copper oxide is reduced by losing oxygen

14
Q

what’s a redox reaction?

A

a reaction involving reduction and oxidation

15
Q

what are the real definitions of reduction and oxidation in terms of electrons?

A

red = gain of electrons
ox = loss of electrons
(OILRIG innit)

16
Q

in this reaction, what gains and what loses electrons?

2Fe + 3Cl2 -> 2FeCl3 give ionic equations as proof.

A
  • iron lost electrons= oxidised:
    2Fe -> 2Fe 3+ + 6e (lost neg thoughts and got positive charge)
  • chlorine got electrons = reduction:
    3Cl2 + 6e- –> 6cl-
    (was 3cl- then 6cl-, got more bad thoughts)
17
Q

what is reduction and oxidation in terms of oxidation number?

A
r = decrease in ox number
ox = increase in ox num
18
Q

metal + acid = ?

A

salt + hydrogen

19
Q

what type of acids undergo redox reactions with some metals?

A

dilute acids

20
Q

give the equation for the reaction of zinc with HCl?

A

Zn(s) + 2HCl (aq) —> ZnCl2(aq) + H2 (g)