how to figure out the ionic charge on a atom/molecule? (1 Viewer)

[deadbeat]

firslty

i know

the group 1 and 2 elements are all +1 and +2 respectively. thats easy

and Flourine-Iodine are -1
Oxygen-sulfer is -2
Nitrogen to phosphoru is -3


is there a way of working out the ionic charge of elements such as nickel,copper, zinc. i.e the elements in the middle. do you work it out by the electron shell that it is on?

also whats the rule for getting the ionic charge of
coumpounds like Carbonate, Borate?

i am a bit lost. do you just have to REMEMBER or are there easier ways you can work it out by looking at the periodic table?

Thanks

 

[tommykins]

THey won't give you some full abstract compound, and if they do they will usually denote it with a bracket and roman numerals ie. Silver(II)Sulfate.

THe metals in the middle section are transition metals, they can have varying valencies.

 

[deadbeat]

here is a M/C question i got...

which of these are incorrect

SO3 2- SULFITE

HPO4 2- HYDROGEN PHOSPHATE

NO2 1- NITRITE

MnO4 2- MAGNITE

SiO3 2- SILICATE


THE ANSWER WAS MAGNITE, HOW DO I KNOW THAT IS NOT MnO4 2- ??

THANKS

 

[Studentleader]

By the time your in year 12 you'll know all the common ones you use, write em out in your calculator.

The teachers will be like OMFG LEARN THESE!1111 but they will really stick to you over time.

Don't worry about it too much

Most metals - Positive

MnO4 2- MAGNITE

Mn = +2
O = 2-
1x+2 + (4x-2) = charge of -6?

 

[deadbeat]

SO3 2- SULFITE

ok so Sulfite is correct because S= 4, O3 = -6 so net = -2?

is that the logic?

 

[Studentleader]

SO3 2- SULFITE

ok so Sulfite is correct because S= 4, O3 = -6 so net = -2?

is that the logic?

Yeah its just a matter of adding em up in most cases

in Redox equations in 3rd term you'll find things like Hydrogen can be +1 or -1 don't know if they call it hydride or what lol

 

[WantToDoBetter]

I think you shouldve already encounted most of the common radicals in the prelim course eg. SO4-2 and NO2-1. These you will just have to memorise, either by straight memory work (recomended) or you can use the valenices of the elements encounted to work out the charge of the radical, what ever works for you.
As for transition metals, i think most have variable valencies and although it might help to commit the common ones to memory eg. Cu+1 and Cu+2, most of they will be dicated to you using roman numerals as tommykins said.
Hope that heaps.
Cheers.

 

[minijumbuk]

I hope this table answers your questions =)

If you still haven't noticed the pattern...

Group I metals have charge +1
Group II metals have charge +2
.........and so forth

Most transition metals have a charge of +2. I'm not sure why that is, I think it's something to do with subshells, but I'm not exactly sure. I'm not sure if you even have to know it =P
But yea, if they don't tell you the charge, just assume it is +2, unless it is Ag or Hg. Rarely will they give you uncommon metals, so just remember transition metals as 2+ EXCEPT Hg and Ag.
And...Pt and Au don't really react...so I doubt they'd make you tell the oxidation states of them two xD