help with chemistry questions please ? :] (1 Viewer)

[s0phhhhx]

im in prelim chem :]
and im confused about moles/avogadros number on this question :

1) determine the number of atoms in 3 x 10^23 molecules of oxygen.



please, and thankyou :]


ALSO - ALMOST FORGOT

can someone please check/correct my working for the following question:

2) determine the number of atoms in 36 g of water


moles: 36g/32.356g
moles: 1.116

1.116 x 6.022 x 10^23
= 6.72 atoms

?

 

[iRuler]

I swear, prelim chem sucks.

Sorry no can help tho

 

[s0phhhhx]

i hate moles .

thanks anyways :]

 

[luv2luvurmama]

You have to use Avocado's number.

 

[ohexploitable]

1) determine the number of atoms in 3 x 10^23 molecules of oxygen.

Oxygen molecules are O₂ so there are 6x10²³ O atoms?

 

[iRuler]

moles: 36g/32.356g
moles: 1.116

1.116 x 6.022 x 10^23
= 6.72 atoms

?

not sure about atoms but for moles, the atomic mass is 18.016

It's H2O not HO2

 

[x jiim]

2) determine the number of atoms in 36 g of water

moles: 36g/32.356g
moles: 1.116

1.116 x 6.022 x 10^23
= 6.72 atoms

?

molar mass of H2O is 2x1 + 16 = 18
moles = mass/molar mass
=36/18
=2moles water present
= 2 x 6.022 x 10^23
= 1.2044x10^24

I think =\

 

[dux&src]

molar mass of H2O is 2x1 + 16 = 18
moles = mass/molar mass
=36/18
=2moles water present
= 2 x 6.022 x 10^23
= 1.2044x10^24

I think =\

That's right.

 

[dux&src]

molar mass of H2O is 2x1 + 16 = 18
moles = mass/molar mass
=36/18
=2moles water present
= 2 x 6.022 x 10^23
= 1.2044x10^24

I think =\

Do you know of a Peter at your school?

 

[x jiim]

Do you know of a Peter at your school?

uh, I know a couple.. there are at least three in my grade =\

 

[dux&src]

Yes, in our grade.
PHYSICS, 4u maths?

 

[s0phhhhx]

molar mass of H2O is 2x1 + 16 = 18
moles = mass/molar mass
=36/18
=2moles water present
= 2 x 6.022 x 10^23
= 1.2044x10^24

I think =\

thankyou !!

 

[Dragonmaster262]

thankyou !!

Use this. I found it very helpful.

 

[mioumiou]

Use this. I found it very helpful.

Thanks!!

 

[thongetsu]

You have to use Avocado's number.

lol. isnt it avagadro's number?

 

[Kamal15]

I swear, prelim chem sucks.

omg i knoe eh

 

[iRuler]

omg i knoe eh

Glad you agree :rofl:

 

[x jiim]

Yes, in our grade.
PHYSICS, 4u maths?

Erm, I don't think that actually rules out any of them =\
Is he very tall and skinny, a halfie, or a bass player?