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 P_TOTAL=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 ßà 2NH₃

                IF THE REACTANTS AND PRODUCTS ARE AT STP DETERMINE

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

                EXCESS H_2.

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

_____9. CALCULATE THE u_rms 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 ßà 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) à 2KCl(s) + 3O₂(g)

          THE O₂ PRODUCED IS COLLECTED OVER WATER AND THE FOLLOWING

          DATA IS COLLECTED: T=25⁰C, P_BAR=762 torr, VP_WATER 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 (X_SOLUTE).

                 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 VP_SOLN AND VPL IN torr ?

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

_____17. WHAT IS THE NEW T_B AND T_F OF A SOLUTION CONSISTING OF

                 20.8 g KI IN 500.0 g WATER. FOR WATER K_B=.51^kgC/_mol, K_F=-1.86^kgC/_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

                 K_F=-8.00^kgC/_mol AND T_F,SOLVENT=72.0⁰C, T_F,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