Calculate % Silicon in Silicate Mineral | Danne

[danne89]

Hi!
How many per cent of silicon is there in a silicate mineral, if 0.567 g during analysis gave 0.484 silicon oxide.

Gratefull,
Danne

 

[Gokul43201]

danne,

We really can not help you unless you first make an attempt. What ideas do u have ?

 

[danne89]

Oh, I'm sorry. But I've not any cloue.

 

[dextercioby]

Okay.
$$percentage \ Si =\frac{m_{Si}}{m_{compound}}\cdot 100$$

Daniel.

 

[Gokul43201]

Ask yourself : how much Si is there in SiO2 ?

 

[danne89]

Okej, I've: % Si = Si:Si02 * 100 = 2800:60 ~= 47%

So the weight information's only purpose is to trick you? :(

 

[dextercioby]

No,its purpose is to help answer the problem's question.Reread its text and see what it needs to be done.

Daniel.

 

[danne89]

(0.567 * Si * 100):(0.484 * Si02) = (56.7 * 28):(0.484 * 60) = 1588:29.04 ~= 55%
Sorry for the amount of numbers, I'm using log-table.

 

[dextercioby]

I'm sorry,u have no reason to applogize,even after coming up,again,with a wrong answer.

My answer is "roughly 40%".

Daniel.

 

[apchemstudent]

Hi!
How many per cent of silicon is there in a silicate mineral, if 0.567 g during analysis gave 0.484 silicon oxide.

Gratefull,
Danne

What's the unit of .484 ? grams?

 

[dextercioby]

No,MeV/c^{2}... :tongue:

Daniel.

 

[apchemstudent]

No,MeV/c^{2}... :tongue:

Daniel.

alright... I don't get 40 % when i try this problem out.

SiO2 = total weight

SiO =.484 grams

O = Total weight - .484 + (weight of O inside Silicon oxide)

Well we know how much Oxygen is in there we can easily figure out the percentage of Si...

I'm sorry,u have no reason to applogize,even after coming up,again,with a wrong answer.

My answer is "roughly 40%".

I don't get 40 %... I think you've mistaken SiO for SiO2 (silicon oxide not dioxide)

 

[dextercioby]

Of course it's $SiO_{2}$.

Daniel.

P.S.Does Silicium form oxides at +2??My guess is "no"...

 

[danne89]

% Si = (0.567 * Si * 100):(0.484 * Si*Si02) = (56.7 * 28):(0.484 * (28 + 28 + 2 * 16)) = 1587.6:(0.484 * 88) = 42.59%

Yes! At least my slow head isn't act as a fools mind.

 

[dextercioby]

Explain that part:
$$(28+28+2*16)$$

Why on Earth did u add 28 TWICE?

Daniel.

P.S.Is it $$Si_{2}O_{2}$$ ??

 

[danne89]

I add the Si and Si02 together.
Edit: Which seems to be quite idiotic now...

 

[danne89]

Can I have some more hint?

 

[dextercioby]

Why would you do that for?It's only SiO_{2} in the mineral.It has the molecular mass of 60 and it's content of Si is
$$\frac{28}{60}$$

Is that enough ?

Daniel.

 

[danne89]

No. I can't solve it.

 

[dextercioby]

Okay.Here goes:
28g Si---------------------------->60g SiO_{2}
x g Si------------------------------>0.484g SiO_{2}

Find "x" and then:

x g Si-------------------------->0.567g mineral
y g Si-------------------------->100g mineral

Find "y".That will be the answer to your problem
"y"% Si in the mineral...

Daniel.

 

[danne89]

So the answer is ~ 39% But I don't understand this. Can you redirect me to a good site, I've search a bit on google already.

 

[dextercioby]

I'm sorry,but i don't follow...Good site on what??And what exactly didn't u understand??

Daniel.

 

[Gokul43201]

So the answer is ~ 39% But I don't understand this. Can you redirect me to a good site, I've search a bit on google already.

danne, this is not very hard, and you've nearly got it. I'm quite sure that the question really means "silicon dioxide" rather than "silicon oxide". All silicates (that I know of at least - like sodium, potassium, aluminum,...) are composed of SiO2 units, so this must be what they are talking about.

First of all you found out how much Si there is in SiO2. You got this to be about 46.7%. This simply means that every 100g of SiO2 will contain 46.7g of Si.

But you are told how much SiO2 there is (0.484g), so you can determine how much Si there should be in 0.484g of SiO2. This will just be 46.7% of 0.484g. What does that give you ? Divide this number by the total weight to get the required percentage.

You should get about 39.8%

 

[danne89]

46.7 * 0.484 : 0.567 = 22.6028:0.567 = 39.86 %
I'm a right now?

 

[Gokul43201]

Yes, that's right. But you have to divide the left side by 100 to account for the percentage.