# class9 - Class #9 Gases & Stoichiometry CHEM 107 A. Bengali...

This preview shows pages 1–8. Sign up to view the full content.

Class #9 CHEM 107 A. Bengali Texas A&M University Qatar

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
Gas Law ) A “warm-up” problem, from an old exam ) “Clouds” in deep space contain 10 10 H 2 molecules per m 3 , at 25 K ) Find P in atmospheres
Gas Cloud Problem ) P=nRT/V = (n/V)RT ) (n/V) = 10 10 molecules/m 3 ) That’s 1.66x10 -14 mole/m 3 or 1.66x10 -17 mol/L ) Then solve for P, get 3.4x10 -17 atm.

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
) Chemical equations relate #’s of moles, as always! ) Gas law relates # of moles to P, V, T ) Allows us to find amount of gas produced or consumed in terms of P, V, T, . ...
Gas Stoichiometry ) Mg dissolves in HCl, produces H 2 Mg (s) + 2H 3 O + (aq) Mg 2 + (aq ) + H 2 (g) +2H 2 O ) Dissolve 2.0 g Mg in excess HCl ) Predict volume of H 2 produced

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
Mg/HCl Mg (s) + 2H 3 O + (aq) Mg 2 + (aq )+H 2 (g) +2H 2 O Use P = 1 atm, T = 25 C = 298 K 2 g ? L First get moles of H 2 2 g Mgx 1 mol Mg 24.3 g Mg x 1 mol H 2 1 mol Mg = 0.0823 mol H 2
Mg/HCl ) 0.0823 mol H 2 = ? L at 1 atm, 25 C V= nRT P = ( 0 . 0823 )( 0 . 0821 )( 298 ) 1 =2 . 01 L

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
This is the end of the preview. Sign up to access the rest of the document.

## This note was uploaded on 03/29/2008 for the course CHEM 107 taught by Professor Generalchemforeng during the Spring '07 term at Texas A&M.

### Page1 / 19

class9 - Class #9 Gases & Stoichiometry CHEM 107 A. Bengali...

This preview shows document pages 1 - 8. Sign up to view the full document.

View Full Document
Ask a homework question - tutors are online