[Clarkkent]

What mass of HCl is produced when 4.50 of H(2) and 140.0 of Cl(2) are reacted?

The question is throwing me off, but I think it's asking me the theoretical yield.

Can anyone help?

[Albert]

It depends on the context. I mean, it can be a simple question about limiting reagents: you know, something like

H₂ + Cl₂ <-> 2HCl

If you're a high school student this may be the right point of view; otherwise, if you're right talking about yield (maybe in an inorganic chemistry problem).

[Will]

What mass of HCl is produced when 4.50 of H(2) and 140.0 of Cl(2) are reacted?

4.50/140.0 what?! grams, moles, kilos, dm³, mg....?

[rctrackstar2007]

i think it's moles

[Will]

i think it's moles

The last thing I would've said it is, is moles, because they react in a 1:1 ratio and Cl₂ would be in a huge excess if it was moles, however it was something like grams the situation would be more realistic as there would then be 2.23 moles of H₂ and 1.97 moles of Cl₂ (which would give 3.949 moles of HCl (143.98 grams).

But I could be wrong (and you could be right!), thats why I asked .

[Borek]

Sounds like grams, both masses are close to stoichiometric amounts (4/140). Cl₂ is limiting reagent, H₂ is in excess (that's why it is red ).

[Donaldson Tan]

This is just a limiting reagent problem,

First, covert all your mass in grams to moles before deciding which is limiting reagent.