2 Quik questions

What mass of hydrogen is produced when 10.0g of Aluminium react with excess hydrochloric acid?

What mass of sodium just reacts with 40.0 g of oxygen?

Could you please tell me what answers you got but also how you got them.

Reply 1

Eau

First you would need to write the reactions down:

A. 2Al + 6HCl --> 2AlCl3 + 3H2

B. 4Na + O2 --> 2Na2O

For A, 2 moles of Al gives 3 moles of H2. Since (10/27) moles of Al reacts, (10/27) * (3/2) = (5/9) moles of H2 are produced. Convert this to mass, so 1.1 g of H2.

For B, 4 moles of Na reacts with O2 (provided only Na2O is produced). So since 40/(16*2) moles of O2 reacts, 5 moles of Na reacts. Convert this to mass, so 115 g of Na.

Reply 2

hellom

For A don't you do 10/54 because it's 2AL.I'm sory but I really don't understand how you got these answers could you explan it in a bit more detail.

Thanks...

Reply 3

hungry_hog

no you've already taken the 2 into account in the mole ratio calculation...