UNIT 6 Test PRACTICE (75 pts) No 0.301 t Name: ___________________

Nt t1/2

1.5 Go to one of the lab stations and build models of a) cis-1,2-difluoroethene b) 2-propanol c) S8 (using the yellow atoms).

Bring them over to show the instructor, then return the box to the lab station.

2. 10 a) At-210 has a half-life of 8.10 h. What type of decay would At-210 undergo? ______________________

b) Write an equation for the this reaction : _________________________________

c) Of a 120 mCi sample of At-210, how much will remain after 32.4h? (Show how you can get the answer without

using the log equation.)

Ans: _________

d) How long would it take for 64.0% of an At-210 sample to decay? (Show work.)

Ans: _________

3.6 Write equations for each of the following nuclear reactions to solve for the missing piece: also identify what type of reaction is occurring. reaction: type: a) A silicon-28 nucleus is struck by a proton, knocking a neutron out the other end and producing a ????? _________________________________________ __________ b) A neutron strikes a plutonium-239 (Pu) nucleus and it splits into a xenon-138 and a ????? and three more neutrons: ________________________________________ __________

4.10 Consider the equilibrium reaction: N2(g) + 3 H2O(g) 2 NH3(g) + O3(g) H = +235 kJ a: a) Write the Kc expression in the box at right. b) At 25*C, Kc = 38.5. If an equilibrium mixture of the four gases at 25*C contains 0.250 M N2, 0.180 M H2O & 0.500 M O3, what must the NH3 concentration be? c) At a different temperature, 0.300 M N2 and 0.700 M H2O are placed in a 2.00 L tank. Once equilibrium is established, the NH3 conc is 0.340 M. Determine Kc at this new temp. d) What mass of N2 is present at equilibrium? e) Is the new temp higher or lower than 25*C? Show work:

5.8 a) Based on the graph at right, what is the half-life of X? ____________

(show with markings on the graph how you got that answer)

b) Based on the graph at right, what is the half-life of Y? ____________

(Show your calculations below.)

c) Draw in a line for Z, a radioactive isotope with an initial activity

level of 115 mCi and a half-life of 3.5 h.

d) Which has the most unstable nucleus: X, Y or Z? ___

Activity (mCi)

X

Y

0

20

40

60

80

100

120

140

160

180

0 1 2 3 4 5 6 7 Time (h)

log =

b: ___________

c: ___________

d: ___________

e: ___________

Click here to see the Jing video answers and explanations

6.20 Fill out the chart below NEATLY! Leave the X’s blank

Name Structural formula Line formula Cond. struct. form Mol. formula

Ex:

a b c d e 7.12 THIS MUST BE DONE NEATLY. Practice on scrap paper first. Draw three structural isomers for each of the following. BONUS RISK Draw additional structural isomers. You will gain 0.5 pts for each correct new one you draw, but you will lose 0.5 pts for each repeat or incorrect one you draw. (Beware: You can lose points on this if your mistakes outnumber your correct responses).

a) C6H14

b) C5H10

c) C3H2F2

d) C4H11N

2,4-difluoro-2-butanol CH2FCH2CFOHCH3 C4H8OF2

1,1-difluoro-3-methylheptane

2,2-diiodo-3-hexanone

butyl propyl amine

7-bromo-3-octyne

3-ethylcyclopentene

9.2 Only one of the four molecules above has two optical

isomers; box it, and draw those two optical isomer below.

8.2 Only one of the four molecules above has two geometric

isomers; circle it, and draw those two geometric isomer below.

Scrap paper:

Some particles frequently involved in nuclear reactions:

symbol name

or alpha particle (a helium nucleus)

or beta particle (an electron)

positron (a positive electron?)

neutron

proton (a hydrogen, H-1 nucleus)

deuteron (a deuterium, H-2 nucleus)

gamma ray (not really a particle, but very high energy light)

UNIT 6 Test PRACTICE (75 pts) No 0.301 t Name: ___________________

Nt t1/2

1.5 Go to one of the lab stations and build models of a) cis-1,2-difluoroethene b) 2-propanol c) S8 (using the yellow atoms).

Bring them over to show the instructor, then return the box to the lab station.

2. 10 a) At-210 has a half-life of 8.10 h. What type of decay would At-210 undergo? ______________________

b) Write an equation for the this reaction : _________________________________

c) Of a 120 mCi sample of At-210, how much will remain after 32.4h? (Show how you can get the answer without

using the log equation.)

Ans: _________

d) How long would it take for 64.0% of an At-210 sample to decay? (Show work.)

Ans: _________

3.6 Write equations for each of the following nuclear reactions to solve for the missing piece: also identify what type of reaction is occurring. reaction: type: a) A silicon-28 nucleus is struck by a proton, knocking a neutron out the other end and producing a ????? _________________________________________ __________ b) A neutron strikes a plutonium-239 (Pu) nucleus and it splits into a xenon-138 and a ????? and three more neutrons: ________________________________________ __________

4.10 Consider the equilibrium reaction: N2(g) + 3 H2O(g) 2 NH3(g) + O3(g) H = +235 kJ a: a) Write the Kc expression in the box at right. b) At 25*C, Kc = 38.5. If an equilibrium mixture of the four gases at 25*C contains 0.250 M N2, 0.180 M H2O & 0.500 M O3, what must the NH3 concentration be? c) At a different temperature, 0.300 M N2 and 0.700 M H2O are placed in a 2.00 L tank. Once equilibrium is established, the NH3 conc is 0.340 M. Determine Kc at this new temp. d) What mass of N2 is present at equilibrium? e) Is the new temp higher or lower than 25*C? Show work:

5.8 a) Based on the graph at right, what is the half-life of X? ____________

(show with markings on the graph how you got that answer)

b) Based on the graph at right, what is the half-life of Y? ____________

(Show your calculations below.)

c) Draw in a line for Z, a radioactive isotope with an initial activity

level of 115 mCi and a half-life of 3.5 h.

d) Which has the most unstable nucleus: X, Y or Z? ___

Activity (mCi)

X

Y

0

20

40

60

80

100

120

140

160

180

0 1 2 3 4 5 6 7 Time (h)

log =

b: ___________

c: ___________

d: ___________

e: ___________

11.9 h t =11.9 h

6.20 Fill out the chart below NEATLY! Leave the X’s blank

Name Structural formula Line formula Cond. struct. form Mol. formula

Ex:

a b c d e 7.12 THIS MUST BE DONE NEATLY. Practice on scrap paper first. Draw three structural isomers for each of the following. BONUS RISK Draw additional structural isomers. You will gain 0.5 pts for each correct new one you draw, but you will lose 0.5 pts for each repeat or incorrect one you draw. (Beware: You can lose points on this if your mistakes outnumber your correct responses).

a) C6H14

b) C5H10

c) C3H2F2

d) C4H11N

2,4-difluoro-2-butanol CH2FCH2CFOHCH3 C4H8OF2

1,1-difluoro-3-methylheptane

2,2-diiodo-3-hexanone

butyl propyl amine

7-bromo-3-octyne

3-ethylcyclopentene

9.2 Only one of the four molecules above has two optical

isomers; box it, and draw those two optical isomer below.

8.2 Only one of the four molecules above has two geometric

isomers; circle it, and draw those two geometric isomer below.