Hi everyone(adsbygoogle = window.adsbygoogle || []).push({});

I've just got a few questions regarding some Chemistry stuff I've been doing out of my textbook (Year 11 Chemistry). We've been learning this in class, I thought I understood it, but I must be blacking out a little bit.

5) Calculate the mass of one atom of:

a) Zinc

Zn

65.4 AMU.

In one mole of Zn there is 65.4g/ mol.

How do I go from here? I thought it would've been something like 1 x 6.02x 10 (23), but that would show the amount of atoms in total, and if I'm trying to find the mass of one atom, how do I go about it? do I divide by the atomic weight? am I doing something wrong?

Also, the molar mass and molecular weight, is that just the same as the mass of one mole of [whatever]?

and...

10) What is the mass of:

c) 6.24 x 10-2 mol hydrogen gas?

H x 1 + 0 x 2

1 + 32

= 33 AMU.

So in one mole of H02 there is 33g/ mol.

6.24 x 10-2

-------------

33

Am I on the right path?

Is Molecules the same thing as Atoms? I often get confused with moles and molecules, but understand they are 2 different things.

11) How many molecules are there in 7.0g of nitrogen gas, N2? How many nitrogen atoms are there in this sample?

N x 2

14 x 2

= 28 AMU

Therefore one mole of N2 has a mass of 28g/ mol.

7

--

28

= 0.25 mol.

0.25 x 6.02 x 10 (23)

Please point out if I'm doing anything incorrectly.

I don't expect answers for the questions, as they aren't really homework questions, but I'd really like to know how to do them, as it's holidays and I haven't got a teacher handy. I've given all the questions a go, to the best of my ability and knowledge.

Thanks so much.

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# Homework Help: A few basic questions

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