Ask a question

gas stoichiometry question

A foul smelling gas produced by the reaction of HCL and Na2S:

2HCl + Na2S --> 2NaCl + H2S

is collected in and a 1.00 L sample was found.  How many moles were found in the sample knowing the reaction took place under STP conditions and how many grams of HCl are produced by the reaction?


I think some information is missing?  I get 3.25 g HCl which isn't an option..


the choices are

a.) 2 g

b.) 0.82 g

c.) 0.32 g

d.) 8 g


Please help me or let me know what is missing!  Thanks!

2 Answers by Expert Tutors

Tutors, sign in to answer this question.
Robert J. | Certified High School AP Calculus and Physics TeacherCertified High School AP Calculus and Ph...
4.6 4.6 (13 lesson ratings) (13)

You can use dimensional analysis.

You start with what's given:

1.00 L of H2S (1 mol of H2S/22.41 L)(2 mol of HCl/1 mol of H2S)(36.46 g of HCl/1 mol of HCl) = 3.25 g of HCl

I got the same answer as you got.


Vicki N. | Top International Teacher, English Foreign Language Certified (TEFL)Top International Teacher, English Forei...
5.0 5.0 (104 lesson ratings) (104)

Hi Liz,

If you show your work, I'm sure a tutor will be happy to assist you.


Vicki N.