CHM 2045 EXAM 5

CHM 2045 EXAM 5

_____1. A GAS EXERTS A P=4.00 ATM AND OCCUPIES A 10.0L VESSEL. IT IS

ALLOWED TO EXPAND INTO A 20.0L VESSEL AT CONSTANT n AND T.

WHAT IS THE NEW P IN torr?

A) 6.00 torr B) 1.52X103 torr C) 3.04X103 torr D) 190 torr

_____2. A GAS HAS T=27.00C IN A 10.0L VESSEL. IT IS FORCED, AT CONSTANT

n AND P, INTO A 2.00X103 mL VESSEL. WHAT IS THE NEW T IN 0C?

A) –193.0 B) 8.92X104 C) 5.4 D) -213.2

_____3. WHAT VOLUME DOES 22.0g CO2 OCCUPY AT STP?

A) 6.72L B) 5.6L C) 29.1L D) 11.2L

_____4. A GAS OCCUPIES A 2.00L VESSEL AND HAS P=5.00ATM AT T=127.00C.

THE GAS IS ALLOWED TO EXPAND, AT CONSTANT n, INTO A 10.0L VESSEL

AT 27.00C. CALCULATE THE NEW P IN ATM.

A) .750 B) .213

C) 570 D) 1.33

_____5. A GAS OCCUPIES 30.0L AT 57.20C UNDER 380.0 torr. WHAT IS n ?

A) 3.19 B) 1.81

C) 9490 D) .553

_____6. DETERMINE THE MOLAR MASS OF A GAS IF 1.60g OCCUPIES

100.0mL AT 37.00C UNDER 5.00 ATM.

A) 50.9 g/mol B) 40.7 g/mol C) 6.08 g/mol D) 81.4 g/mol

_____7. CONSIDER A MIXTURE OF 4.4 g CO2 AND 5.6 g N2 WITH PTOTAL=9.0 ATM

DETERMINE PARTIAL P FOR CO2 AND N2.

A) .33, .67 B) 3.0, 6.0 C) .76, .24 D) 3.3, 6.7

_____8. CONSIDER THE REACTION : N2 + 3H2 2NH3

IF THE REACTANTS AND PRODUCTS ARE AT STP DETERMINE

THE VOLUME OF NH3 PRODUCED WHEN 9.00 L N2 IS REACTED WITH

EXCESS H2.

A) 14.0 L B) 27.0 L C) 42.0 L D) 18.0 L

_____9. CALCULATE THE urms FOR N2 GAS AT 1270C

A) 10.6 m/s B) 597 m/s C) 336 m/s D) 59.3 m/s

_____10. CONSIDER THE REACTION: N2 + 3H2 2NH3

IF 2.00L N2 UNDER 3.00 ATM AT 27.00C REACTS WITH EXCESS H2 AT

THE SAME T,P HOW MANY LITERS OF NH3 CAN BE PRODUCED

UNDER 5.00 ATM AT 52.00C.

A) 4.00L B) 2.OOL C) 2.63L D) 68.3L

FOR THE NEXT 3 PROBLEMS CONSIDER THE FOLLOWING. A SOLID SAMPLE

OF KClO3 IS DECOMPOSED ACCORDING TO:

2KClO3(s) 2KCl(s) + 3O2(g)

THE O2 PRODUCED IS COLLECTED OVER WATER AND THE FOLLOWING

DATA IS COLLECTED: T=250C, PBAR=762 torr, VPWATER AT 250C=23 torr

V OF O2 COLLECTED=0.40 L

_____11. DETERMINE PARTIAL P OF O2 IN ATM

A) 0.972 ATM B) 1.03 ATM C) 1.00 ATM D) .400 ATM

_____12. DETERMINE THE MOLES OF O2 COLLECTED

A) 0.017 mol B) 0.016 mol C) 0.19 mol D) 12 mol

_____13. DETERMINE THE GRAMS OF KClO3 USED

A) 1.3 g B) 2.0 g C) 15.5 g D) .011 g

_____14. A (L) HAS NBP=58.00C AND HEAT OF VAP.=77.0 kJ/mol

WHAT IS ITS VP AT 98.00C ?

A) 762 TORR B) 2.29 X 103 TORR C) 1.56 X 104 TORR D) 3.01 TORR

_____15. A SOLUTION CONSISTS OF 40.0 g OF SOLUTE( MOLAR MASS=250.0 g/mol)

IN 200.0 mL H2O (D=1.000 g/mL). CALCULATE ITS MOLALITY(m) AND

MOLE FRACTION (XSOLUTE).

A) m=.800 mol/kg X=.0142 B) m=.800 mol/kg X=.00889

C) m=1.25 mol/kg X=.0144 D) m=.160 mol/kg X=.016

_____16. A PURE SOLVENT HAS VP=124 torr AND MOLAR MASS=86.0 g/mol

IF 5.00g SOLUTE(NON-ELECTROLYTE M=50.0 g/mol) ARE DISSOLVED IN

43.0g OF SOLVENT. WHAT IS VPSOLN AND VPL IN torr ?

A) 103, 21 B) 117, 7.0 C) 78, 36 D) 121, 4.0

_____17. WHAT IS THE NEW TB AND TF OF A SOLUTION CONSISTING OF

20.8 g KI IN 500.0 g WATER. FOR WATER KB=.51kgC/mol, KF=-1.86kgC/mol

A) 100.50C, -1.860C B) 101.00C, -3.720C

C) 98.00C, -7.440C D) 100.250C, -.930C

_____18. WHAT IS THE OSMOTIC PRESSURE OF A SOLUTION CONSISTING OF

10.0 g OF A NON-ELECTROLYTE SOLUTE WITH MOLAR MASS

OF 50.0 g DISSOLVED IN SUFFICIENT WATER TO MAKE 400.0 mL OF

SOLUTION AT 270C?

A) 12.3 torr B) 12.3 atm C) 24.6 atm D) 2.22 atm

_____19. A SOLUTION CONSISTS OF 5.00g OF A NON-ELECTROLYTE SOLUTE

DISSOLVED IN 100.0g OF SOLVENT WITH

KF=-8.00kgC/mol AND TF,SOLVENT=72.00C, TF,SOLUTION=62.00C. WHAT IS THE

MOLAR MASS OF THE SOLUTE IN G/MOL

A) 80.0 B) 40.0 C) 1.60X102 D) 2.00X102

_____20. A SOLUTION CONSISTS OF 10.0mg OF A NON-ELECTROLYTE SOLUTE

DISSOLVED IN SUFFICIENT WATER TO MAKE

2.00mL OF SOLUTION. THE OSMOTIC P OF THE SOLUTION=25.3 torr

AT 270C. WHAT IS THE MOLAR MASS OF THE SOLUTE IN G/MOL?

A) 3.70X103 B) 424 C) 3.7x102 D) 741