CEM 142 Exam 1 (2025) Actual Exam Questions and Answers A+ Graded

CEM 142 Exam 1 (2025) Actual Exam
Questions and Answers A+ Graded




Open .system .- .CORRECT .ANSWER-mass/matter .as .well .as .energy .can .flow .in
.and .out .of .the .system


closed .system .- .CORRECT .ANSWER-mass/matter .can .not .flow .into .the .system
.but .energy .can .flow .in .and .out .of .the .system


isolated .system .- .CORRECT .ANSWER-nothing .can .enter .or .leave .the .system

what .is .the .difference .between .state .and .path .function .- .CORRECT .ANSWER-
State .function .depend .only .on .the .initial .and .final .states .but .not .the .path .taken
.while .a .path .function .requires .multiple .steps .and .proofs .to .get .to .the .final
.state


what .does .delta .H .stand .for .- .CORRECT .ANSWER-thermal .energy .in .a .system

endothermic .reaction .- .CORRECT .ANSWER-energy .entering .the .system

exothermic .reaction .- .CORRECT .ANSWER-energy .leaving .the .system

when .bonds .are .being .formed .- .CORRECT .ANSWER-energy .is .released

when .bonds .are .being .broken .- .CORRECT .ANSWER-energy .is .required

entropy .- .CORRECT .ANSWER-measure .of .possible .arrangements

2nd .law .of .thermodynamics .- .CORRECT .ANSWER-for .any .change .in .total
.energy .there .much .be .an .increase .in .entropy


what .unit .is .used .to .show .entropy .- .CORRECT .ANSWER-delta .S

what .happens .to .delta .S .as .you .increase .more .molecules .- .CORRECT
.ANSWER-it .increases


why .does .energy .move .from .hot .to .cold .- .CORRECT .ANSWER-because .once
.energy .is .transferred .to .equilibrium. .there .are .more .possible .arrangements

, what .state .has .the .most .distinguishable .arrangements .- .CORRECT .ANSWER-
gas .because .there .are .no .interactions .and .its .random

what .has .a .higher .entropy? .water .freezing .or .ice .melting .- .CORRECT .ANSWER-
ice .melting .because .there .are .more .possible .arrangements .due .to .more
.molecules .and .less .interactions


does .entropy .have .to .increase .in .the .system .a .process .to .exist .- .CORRECT
.ANSWER-no, .it .just .has .to .occur .in .that .universe. .either .system .or
.surroundings


how .do .you .calculate .Snet .total .- .CORRECT .ANSWER-Ssytem .+ .Ssurroundings

what .has .the .highest .Hvap .- .CORRECT .ANSWER-the .molecules .with .more
.hydrogen .bonds .because .more .energy .is .need .to .overcome .the .IMF's


what .is .the .relationship .between .delta .H .and .T .- .CORRECT .ANSWER-entropy=
.thermal .energy/temperature


Gibbs .free .energy .equation .- .CORRECT .ANSWER-ΔG .= .ΔH .- .TΔS

will .this .process .occur .

exothermic .(-) .and .entropy .(+) .- .CORRECT .ANSWER-yes, .G .will .be .negative

will .this .process .occur

endothermic .(+) .and .entropy .(-) .- .CORRECT .ANSWER-no, .G .will .be .positive

will .this .process .occur

endothermic .(+) .and .entropy .(+) .- .CORRECT .ANSWER-depends .on .T...

why .do .we .use .Gibbs .free .energy .- .CORRECT .ANSWER-because .it .is
.impossible .to .record .the .entropy .of .the .entire .universe. .therefore .Gibbs .uses
.terms .to .reference .the .system


how .do .you .make .a .system .more .thermodynamically .favorable .- .CORRECT
.ANSWER-cool .it .down .because .you .want .S .and .T .to .be .smaller


equilibrium .- .CORRECT .ANSWER-reaction .or .process .goes .forward .and .back .at
.the .same .rate


what .is .an .example .of .a .molecule .being .at .equilbrium .- .CORRECT .ANSWER-
water .at .100.. .it .has .not .completed .the .phase .change .therefore .not .can .be
.observed .because .it .is .stuck