CHEM z103
MODULE z6 z2022
Question z1
Not zyet zgraded z/ z10 zpts
Click zthis zlink zto zaccess z the z Periodic z Table. z This z may z be z helpful
z throughoutzthe zexam.
List zand zexplain zif zeach zof zthe zfollowing zsolutions zconducts zan zelectric
zcurrent: z sodium z chloride z (NaCl), z hydrochloric z acid z (HCl) z and z sugar
z(C 6H12 O6).
Sodium z chloride z (NaCl) zis z an zionic z compound z and z conducts z since z it z forms
z ionszin zsolution. zHydrochloric zacid z(HCl) zis za zpolar zcompound zand zconducts
zsince zit zforms z ions z in z solution. z Sugar z (C6H12O6) z is z a z molecular z compound
z but z does z not zform zions zin zsolution zso zit zdoes znot zconduct.
Question z2
Not zyet zgraded z/ z10 zpts
Explain zhow zand zwhy zthe zpresence zof za zsolute zaffects zthe zboiling zpoint zof
zazsolvent.
The zpresence zof za zsolute zraises zthe zboiling zpoint zof za zsolvent zby zlowering
zthezvapor zpressure zof zthe zsolvent. z With z this zlower zvapor zpressure, zmore
zheat z(a zhigher zboiling zpoint) zis zrequired zto zraise z the z vapor zpressure zto
zatmospheric zpressure.
Question z3
Not zyet zgraded z/ z10 zpts
Click zthis zlink zto zaccess z the z Periodic z Table. z This z may z be z helpful
z throughoutzthe zexam.
, Rank zand zexplain zhow zthe zfreezing zpoint zof z0.100 zm zsolutions zof zthe
zfollowing zionic zelectrolytes zcompare, zList zfrom zlowest zfreezing zpoint zto
zhighest zfreezingzpoint.
GaCl3, zAl2(SO4)3, z NaI, z MgCl2
Your zAnswer:
Al2(SO4)3 z-> z2Al3+, z 3SO4 z -2 z z z= z z = z5 zions z z -> z most z ions z= zlowest
z freezing zpoint
GaCl2 z-> zGa3+, z Cl- z z z z z=
z 4 zions zMgCl2 z = z3 zions
NaI z= z2 zions z- z> zleast zions z= zhighest zfreezing zpoint
GaCl3 → Ga+3 + 3 zCl- ∆tf z= z1.86 zx z0.1 zx z4 z=
3rd zlowest zFP
3 zSO4
Al2(SO4)3 → 2 z Al+3 + -3 ∆tf z= z1.86 zx z0.1 zx z5 z=
lowest zFP
NaI → Na+ + I- ∆tf z= z1.86 zx z0.1 zx z2
= zhighest zFP
MgCl2 → Mg+2 + 2 zCl- ∆tf z= z1.86 zx z0.1 zx z3
= z2nd zlowest zFP
FP: Al2(SO4)3 z z z< z GaCl 3 z z z< z MgCl2 z z z< z NaI
Question z4
Not zyet zgraded z/ z10 zpts
Click zthis zlink zto zaccess z the z Periodic z Table. z This z may z be z helpful
z throughoutzthe zexam.
Show zthe zcalculation zof zthe z mass z percent zsolute z in za zsolution zof z20.8
z gramszof z Ba(NO3)2 z z zin z 400 z grams z of z water. z z Report z your z answer z to z 3
zsignificant zfigures.
MODULE z6 z2022
Question z1
Not zyet zgraded z/ z10 zpts
Click zthis zlink zto zaccess z the z Periodic z Table. z This z may z be z helpful
z throughoutzthe zexam.
List zand zexplain zif zeach zof zthe zfollowing zsolutions zconducts zan zelectric
zcurrent: z sodium z chloride z (NaCl), z hydrochloric z acid z (HCl) z and z sugar
z(C 6H12 O6).
Sodium z chloride z (NaCl) zis z an zionic z compound z and z conducts z since z it z forms
z ionszin zsolution. zHydrochloric zacid z(HCl) zis za zpolar zcompound zand zconducts
zsince zit zforms z ions z in z solution. z Sugar z (C6H12O6) z is z a z molecular z compound
z but z does z not zform zions zin zsolution zso zit zdoes znot zconduct.
Question z2
Not zyet zgraded z/ z10 zpts
Explain zhow zand zwhy zthe zpresence zof za zsolute zaffects zthe zboiling zpoint zof
zazsolvent.
The zpresence zof za zsolute zraises zthe zboiling zpoint zof za zsolvent zby zlowering
zthezvapor zpressure zof zthe zsolvent. z With z this zlower zvapor zpressure, zmore
zheat z(a zhigher zboiling zpoint) zis zrequired zto zraise z the z vapor zpressure zto
zatmospheric zpressure.
Question z3
Not zyet zgraded z/ z10 zpts
Click zthis zlink zto zaccess z the z Periodic z Table. z This z may z be z helpful
z throughoutzthe zexam.
, Rank zand zexplain zhow zthe zfreezing zpoint zof z0.100 zm zsolutions zof zthe
zfollowing zionic zelectrolytes zcompare, zList zfrom zlowest zfreezing zpoint zto
zhighest zfreezingzpoint.
GaCl3, zAl2(SO4)3, z NaI, z MgCl2
Your zAnswer:
Al2(SO4)3 z-> z2Al3+, z 3SO4 z -2 z z z= z z = z5 zions z z -> z most z ions z= zlowest
z freezing zpoint
GaCl2 z-> zGa3+, z Cl- z z z z z=
z 4 zions zMgCl2 z = z3 zions
NaI z= z2 zions z- z> zleast zions z= zhighest zfreezing zpoint
GaCl3 → Ga+3 + 3 zCl- ∆tf z= z1.86 zx z0.1 zx z4 z=
3rd zlowest zFP
3 zSO4
Al2(SO4)3 → 2 z Al+3 + -3 ∆tf z= z1.86 zx z0.1 zx z5 z=
lowest zFP
NaI → Na+ + I- ∆tf z= z1.86 zx z0.1 zx z2
= zhighest zFP
MgCl2 → Mg+2 + 2 zCl- ∆tf z= z1.86 zx z0.1 zx z3
= z2nd zlowest zFP
FP: Al2(SO4)3 z z z< z GaCl 3 z z z< z MgCl2 z z z< z NaI
Question z4
Not zyet zgraded z/ z10 zpts
Click zthis zlink zto zaccess z the z Periodic z Table. z This z may z be z helpful
z throughoutzthe zexam.
Show zthe zcalculation zof zthe z mass z percent zsolute z in za zsolution zof z20.8
z gramszof z Ba(NO3)2 z z zin z 400 z grams z of z water. z z Report z your z answer z to z 3
zsignificant zfigures.
