February 27, 2017

Homework Help: Chemistry

Posted by ChemLover on Friday, August 12, 2011 at 7:51pm.

A sample of zinc metal reacts completly with an excess of hydrochloric acid:

Zn(s) + 2HCl(aq) --> ZnCl2(aq) + H2(g)

The hydrogen gas produced is collected over water at 25.0 °C. The volume of the gas is 78.0 L & the pressure is 0.980 atm. Calculate the amount of zinc metal in grams consumed in the reaction. (vapor pressure of water at 25 °C = 23.8mmHg)

okay so for this problem i first used PV=nRT and i found moles of H2 which was 3.13 mol H2 and then i converted that into 3.13 mol Zn because i mol of Zn = 1 mol of H2

after i took the mm of Zn (65.38 g/mol)
and multiplied it by 3.13 mol Zn to get grams.

and i got 205 g. The actual answer in my notes is 198 g Zn..i did it a couple of times but i cant seem to get this answer..and i missing a step..thanks for the help

Answer This Question

First Name:
School Subject:

Related Questions

More Related Questions