Calculate the mass of 4.56 moles of helium. And Calculate the number of atoms in 12g of zinc.?

Question

Please help I think I am making this difficult than it really is.

Answer 1

For the first one, multiple the number of moles by the molecular mass of Helium. Helium is mono-atomic (one atom per molecule) so the atomic mass of Helium is used:

4.56 moles * 4.003 g/mol = ? (you can at least do the math)

For the second part, each mole of pure substance contains Avogadro's number of molecules (or atoms for an element).

The number of moles of Zinc is the mass divided by the atomic mass (also called the atomic weight). For Zinc this is 65.38 g/mol:

12 g / 65.38 g/mol = number of moles of Zinc.

Each mole contains 6.022 * 10^23 atoms of Zinc, so just multiple the number of mole above by 6.022 * 10^23 atoms/mole to get your answer.

Answer 2

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Answer 3

keep in mind that there are 6.02 x 10^23 atoms/mole So at the same time as uncertain use dimensional diagnosis: (4.05 x 10^34 atoms)(a million mole/6.02 x 10^23 atoms) <=== we favor to have atoms cancel = 8.06 x 10^10 moles What you probably did became multiply atoms with the help of Avogadro's quantity. you ought to have divided. in case you checked instruments after fixing the way you probably did, you ought to are transforming into: atoms^2/mole

Answer 4

1) wut my chem teacher taught me might help u in finding the answer to this question....basically there are 4 equations u gotta remember, and they are

number of moles = no. of particles / Avogadro constant
=mass (g) / molar mass (g mol^-1)
= volume of gas ( dm^3) / molar volume of gas
(mol dm^-3)
= molarity (M) x volume(cm^3) /1000

for question 1, u just need to substitute the values into the equation number of moles = mass / molar mass

and for question 2, u just need to substitute the values into the equation, number of moles = number of particles (in this case atoms) / Avogadro constant....

hope that helped....good luck!!

Answer 5

4.56moles H2 *(2g H2/1moleH2)=9.12g H2

12g Zn (1mole Zn/ 65.4g Zn)= .183 mole Zn
.183 mole Zn *(6.02x10^23/1mole Zn)=1.10x10^23 atoms Zn

Answer 6

no you do it

your homework

look at grams per mole

look up Avogadro's number, then call him maybe if you need more help