CEM 142 EXAM 3 MSU ALL QUESTIONS AND CORRECT ANSWERS!!!!
ALREADY GRADED A+
What do you know about reactions? (make a list) - (answer)-Atoms are conserved. They are only re-
arranged.
-Properties of products are emergent (not a mixture of the reactants properties).
-Reactions can be classified by the type of reaction (how it occurs).
-Reactions are always accompanied by an energy change (can be exo and endo) that results from
changed in interactions (bonds and IMFs) in the reactants and products.
-Reactions are always accompanied by an entropy change.
What are the two main typed of reactions? - (answer)-Acid-base
-Redox
*Always accompanied by a changed in entropy.
Can you predict the properties of products if you know the properties of the reactants?
A. Yes
B. No
C. It depends
D. I dont know - (answer)-B
*Properties include smell, melting point, boiling point, and color.
For the reaction: A+B-->C
If A is yellow and B is blue, what color is C?
A. Yellow
B. Blue
C. Green
D. I dont know - (answer)-D
*React NOT mix. C = completely new product.
,CEM 142 EXAM 3 MSU ALL QUESTIONS AND CORRECT ANSWERS!!!!
ALREADY GRADED A+
What thermodynamic function tells you about how far a reaction will "go"?
A. Delta H
B. Delta S (system)
C. Delta G
D. None of these - (answer)-C
*If (+) will NOT happen.
*If (-) WILL happen.
What thermodynamic function tells you about how fast a reaction will "go"?
A. Delta H
B. Delta S (system)
C. Delta G
D. None of these - (answer)-D
*Delta H = energy change / only heat.
*Delta S = Number of possible arrangements in system.
*Delta G = How far the reaction will go.
Reactions can "go" both ____________ and _____________! The sign of __________ will tell you
whether a reaction will go forwards or backwards. - (answer)-Forwards and Backwards.
-Delta G.
How fast a reaction goes depends on...? - (answer)-Activation Energy.
Acid Base reaction are ____________. (speed). However, this does not mean that an Acid Base reaction
will go to...? - (answer)-Fast.
-Completion.
,CEM 142 EXAM 3 MSU ALL QUESTIONS AND CORRECT ANSWERS!!!!
ALREADY GRADED A+
HCl(g) +H2O--> H3O+(aq) +Cl-(aq)
This reaction occurs ______________ and only the ______________ are detectable in the reaction
mixture. - (answer)-Immediately.
-Products.
If you dissolve 0.1 mol HCl in 1L solution-immediately the pH = ? However if you dissolve 0.1 mol acetic
acid in 1L solution-immediately the pH =? - (answer)-1.
-2.9.
Weak Acid Base Reaction are _______ but DO NOT go to ___________. - (answer)-Fast.
-Completion.
Rusting-oxidation of Iron-tends to be slow (you would have to wait a while)-but if you leave it long
enough the reaction will...? - (answer)-Go to completion.
The rate of a reaction has NOTHING to fo with the position of ____________. - (answer)-Equilibrium.
(How fast a reaction is has nothing to do with how far it goes.)
A rate is a ________ in something per unit of time. e.g. speed is miles per hour (miles/hr or mph) or
km/s. - (answer)-Change.
If you travel 120 miles in 2 hours, your rate is...?
A. 120 mph
B. 60 mph
C. 240 mph
D. It depends
*Change in distance traveled / change in time.
Delta Distance / Delta time. - (answer)-B.
, CEM 142 EXAM 3 MSU ALL QUESTIONS AND CORRECT ANSWERS!!!!
ALREADY GRADED A+
(120 miles / 2 hours = 60 mph).
Reaction Rates:
What is changing per unit of time? - (answer)-The amount of the reactant or product (moles!).
Most reactions take place in ____________. So we can use molarity (M, mol/L) as the amount of
reactant (or product). - (answer)-Solutions.
The rate of a reaction is...? - (answer)-the change in concentration per unit of time M/times (or mol/L.s).
-Delta[x]/Delta t.
If the concentration of a reactant X, [X] changed from 1.5M to 0.5 M over 10 seconds, the rate Ould be
change in concentration / change in time, or Delta [X] / Delta t.
A. 1.5 mol/L.s
B. 0.15 mol/L.s
C. 1.0 mol/L.s
D. 0.1 mol/L.s
What is the rate in M/s (or mol/L.s)? - (answer)-D
*(1.5M-0.5M)/10s
*Rate = 1.0M / 10s
*Rate = .1M/s (or 0.1 mol/L.s).
*This rate we just calculated is just an AVERAGE rate (over the time period of 10 seconds).
Rates are usually not ____________. - (answer)-Constant.
*You fan's grow at a constant rate-most reactions don't happen at a constant rate.
ALREADY GRADED A+
What do you know about reactions? (make a list) - (answer)-Atoms are conserved. They are only re-
arranged.
-Properties of products are emergent (not a mixture of the reactants properties).
-Reactions can be classified by the type of reaction (how it occurs).
-Reactions are always accompanied by an energy change (can be exo and endo) that results from
changed in interactions (bonds and IMFs) in the reactants and products.
-Reactions are always accompanied by an entropy change.
What are the two main typed of reactions? - (answer)-Acid-base
-Redox
*Always accompanied by a changed in entropy.
Can you predict the properties of products if you know the properties of the reactants?
A. Yes
B. No
C. It depends
D. I dont know - (answer)-B
*Properties include smell, melting point, boiling point, and color.
For the reaction: A+B-->C
If A is yellow and B is blue, what color is C?
A. Yellow
B. Blue
C. Green
D. I dont know - (answer)-D
*React NOT mix. C = completely new product.
,CEM 142 EXAM 3 MSU ALL QUESTIONS AND CORRECT ANSWERS!!!!
ALREADY GRADED A+
What thermodynamic function tells you about how far a reaction will "go"?
A. Delta H
B. Delta S (system)
C. Delta G
D. None of these - (answer)-C
*If (+) will NOT happen.
*If (-) WILL happen.
What thermodynamic function tells you about how fast a reaction will "go"?
A. Delta H
B. Delta S (system)
C. Delta G
D. None of these - (answer)-D
*Delta H = energy change / only heat.
*Delta S = Number of possible arrangements in system.
*Delta G = How far the reaction will go.
Reactions can "go" both ____________ and _____________! The sign of __________ will tell you
whether a reaction will go forwards or backwards. - (answer)-Forwards and Backwards.
-Delta G.
How fast a reaction goes depends on...? - (answer)-Activation Energy.
Acid Base reaction are ____________. (speed). However, this does not mean that an Acid Base reaction
will go to...? - (answer)-Fast.
-Completion.
,CEM 142 EXAM 3 MSU ALL QUESTIONS AND CORRECT ANSWERS!!!!
ALREADY GRADED A+
HCl(g) +H2O--> H3O+(aq) +Cl-(aq)
This reaction occurs ______________ and only the ______________ are detectable in the reaction
mixture. - (answer)-Immediately.
-Products.
If you dissolve 0.1 mol HCl in 1L solution-immediately the pH = ? However if you dissolve 0.1 mol acetic
acid in 1L solution-immediately the pH =? - (answer)-1.
-2.9.
Weak Acid Base Reaction are _______ but DO NOT go to ___________. - (answer)-Fast.
-Completion.
Rusting-oxidation of Iron-tends to be slow (you would have to wait a while)-but if you leave it long
enough the reaction will...? - (answer)-Go to completion.
The rate of a reaction has NOTHING to fo with the position of ____________. - (answer)-Equilibrium.
(How fast a reaction is has nothing to do with how far it goes.)
A rate is a ________ in something per unit of time. e.g. speed is miles per hour (miles/hr or mph) or
km/s. - (answer)-Change.
If you travel 120 miles in 2 hours, your rate is...?
A. 120 mph
B. 60 mph
C. 240 mph
D. It depends
*Change in distance traveled / change in time.
Delta Distance / Delta time. - (answer)-B.
, CEM 142 EXAM 3 MSU ALL QUESTIONS AND CORRECT ANSWERS!!!!
ALREADY GRADED A+
(120 miles / 2 hours = 60 mph).
Reaction Rates:
What is changing per unit of time? - (answer)-The amount of the reactant or product (moles!).
Most reactions take place in ____________. So we can use molarity (M, mol/L) as the amount of
reactant (or product). - (answer)-Solutions.
The rate of a reaction is...? - (answer)-the change in concentration per unit of time M/times (or mol/L.s).
-Delta[x]/Delta t.
If the concentration of a reactant X, [X] changed from 1.5M to 0.5 M over 10 seconds, the rate Ould be
change in concentration / change in time, or Delta [X] / Delta t.
A. 1.5 mol/L.s
B. 0.15 mol/L.s
C. 1.0 mol/L.s
D. 0.1 mol/L.s
What is the rate in M/s (or mol/L.s)? - (answer)-D
*(1.5M-0.5M)/10s
*Rate = 1.0M / 10s
*Rate = .1M/s (or 0.1 mol/L.s).
*This rate we just calculated is just an AVERAGE rate (over the time period of 10 seconds).
Rates are usually not ____________. - (answer)-Constant.
*You fan's grow at a constant rate-most reactions don't happen at a constant rate.
