How many oxygen atoms are in 53.5 g of calcium phosphate?

Question

i know this one shud be easy..but i want to make sure i got it right

umm in response to the anser bewlow, how did u get the 11 gr for Oxygen?

Answer 1

Ok, first you have to find the moles of calcium phospate that are equal to 53.5 grams of it.

To find moles of a compound, you must divide the mass of the compound, by its formula mass. (How much it weighs)

The formula for calcium phospate is Ca3(PO4)2 So you have 3 atoms of of Calcium, 2 atoms of Phosphorous, and 8 atoms of Oxygen.

Since the atomic mass of calcium is 40.08 grams, and there are three atoms calcium all together weighs 120.24 grams.

SInce the atomic mass of phosphorous is 30.97grams, and there are two atoms, phosphorous all together weighs 61.94grams

Since the atomic mass of oxygen is 16.00 grams, and there are eight atoms oxygem all together weighs 128grams

Now add up all the elements total weights and you will get the formula mass for the compount calcium phosphate.

120.24 Calcium
+ 61.94 Phosphorous
+128.00 Oxygen

Equals 310.18grams as the formula mass for ca3(po4)2 Calcium Phosphate


SO now you must divide the grams of compound by the formula mass of the compound to find the number of moles of compound

310.18/53.5

equals 5.797 moles of calcium phosphate

since you want to know how many molecules you must use a factor label equasion to make it easier to figure out.


Okay, I didn't really finish the explanation, because I figured I'm confusing you, and there's no point. But I can help you in the future, with stuff like this if you need it. I'm on all the time. Do you have im? If you still need help with this, I can still help you.

(PS I think you need an equation for this one You have to know the ratio of oxygen atoms to calcium phospate ions, and you can only get that from an eqausion.)

Answer 2

there is 11.045 gr of oxygen atoms are in 53.5 gr of calcium phosphate that would be 2.0769e+23 oxygen atoms.
i hope i`m giving u the right answer.