00:02
Hi there, in this question, we need to supply either the missing formula or the missing name and determine the category of each compound.
00:11
So in our first one, we are given scandium to permanganate.
00:27
So what we have here is a metal ion with a polyatomic ion.
00:33
Therefore, if we identify this, it's going to be a variable -charged ionic.
00:45
We know it's variable -charged ionic.
00:48
Because they give us that roman numeral there.
00:50
The only reason to give us that roman numeral is so that we know the charge of the ion because it can have more than one charge.
00:57
All right, so let's write the formula for this.
00:59
We have scandium, which is sc.
01:02
That roman numeral tells us the charge, it's 2 plus.
01:05
It is with permanganate.
01:07
Permanganate has the formula mn -o -4 with a single negative charge.
01:14
That means we need two of those so that the charges add up to zero.
01:18
So it's going to be scmn -o -4.
01:23
You can either leave the charges there or remove them.
01:28
And it's a variable -charged ionic compound.
01:34
All right.
01:35
For our next compound, we see that we have hydrogen as the positive ion.
01:40
And it is with cr -04, which is chromate.
01:47
All right.
01:47
When hydrogen is the positive ion, with a negative ion, we have an acid.
01:52
And cro4 is a polyatomic ion with oxygen in it.
01:59
So this would be an oxyacid.
02:04
When we are naming oxy acids, we look at the ending of the negative ion.
02:09
It is a -te because it's chromate.
02:13
Therefore, the a -t -e ending changes to i -c, giving us not chromate, but chromic acid.
02:25
All right, so this is chromic acid.
02:28
It's an oxyacid because it contains oxygen.
02:33
And we know it was an acid because the formula led with hydrogen.
02:38
Okay, next we see strontium, which is a metal.
02:44
There is no roman numeral there...