help please

5. 1.3 moles of H_{2}*S*O_{4}
1. 2 moles of A*l_{2}*O_{3}
2. 5 moles of MgO
3. 1.5 moles of NH3
4. 0.7 moles of Br₂
6. 21 moles of CuO
7. 0.6 moles of HNO3
8. 1.2 moles of N*O_{2}
9. 1.4 moles of CaSO4
10. 2.1 moles of N*a_{2}*C*O_{3}
11. 1.3 moles of MgCl2
12. 0.4 moles of Cu(NO3)2

Reply 1

TypicalNerd

Original post by elliechemestry

Much like your other question, what are you trying to calculate? If its the mass in each case, you need to use the formula

Mass (in grams) = molar mass (in g/mol) x moles

You have been given the moles each time and you can calculate the molar mass from the periodic table.

For example, if you needed to calculate the mass of 6 mol of H2O, the periodic table says the relative atomic masses of H and O are 1 and 16, respectively and so the molar mass of water is 2(1) + 1(16) = 18 g/mol (since there are 2 hydrogens in each molecule and there is one oxygen, hence why I multiplied the 1 by 2 and the 16 by 1).

The mass of H2O therefore is 18 g/mol x 6 mol = 108 g

(edited 3 months ago)

Reply 2

Nitrotoluene

Original post by elliechemestry

Hello elliechemestry!
The text you have written is a list of chemicals with the corresponding number of moles.

But what is the question? Could you please tell us?

We are here to help you practise. If you're sharing your work, we'll give you little hints to keep you going. If you're still stuck, we can give you more detailed help. Just let us know which part is confusing you.

Kind regards,
Sandro