Question

[03.09]Calculate the percent composition of calcium in calcium hydroxide.

16%

33%

54%

70%

Answer 1

@iPwnBunnies

Answer 2

Can you make the molecular formula for calcium hydroxide? :3
I told you hydroxide is OH and has a -1 charge. Calcium has a +2 charge in compounds.

Answer 3

How does this have to do with the formula? It's percentages

Answer 4

Yeah, percent composition. How many calcium atoms make up a molecule of calcium hydroxide. The molecular formula will tell us. :3

Answer 5

I vote that its 54% .-. It sounds like it should be half

Answer 6

Why can't you just make the molecular formula? .-.

Answer 7

Calcium has a 2+ charge. Hydroxide, a 1- charge. The molecule has to be 0 charge.
So, we need another ion of hydroxide to make this molecule.
Ca(OH)2 is the molecular formula for calcium hydroxide.
Oh crap, idk if this is atoms or mass. .-.

Answer 8

Ok, yah, it is related to mass. Can you find the mass of a molecule of Ca(OH)2? :33

Answer 9

Ca-40.08 O-16H-1.008

Answer 10

Mhm. And there are 2 atoms of oxygen and hydrogen per molecule.

Answer 11

So 32 and 2

Answer 12

Yas. So the mass of one molecule is 40.08 + 32 + 2 amu = 74 amu
Since there's one atom of calcium, the mass of calcium is just 40 amu.

Percent composition = 40/74 * 100% = 54%

Answer 13

Yay I was right c:

Answer 14

Ca(OH)2
get full molar mass
molar mass of the whole thing - 100%
molar mass of Ca- X
X= (molar mass of Ca* 100) / molar mass if the whole thing meaning Ca(OH)2

Answer 15

Somy. ;3

Answer 16

can we do it mathematically?
Bunnies <3
q is for u

Answer 17

i mean i didn't think of formula or anything

Answer 18

I did do it mathematically, I thought. :3

Answer 19

lmao i didn't think what i said lol