4/29/2013 and 4/30/2013 Standards: 7 (Chemical Thermodynamics)Objectives: Students will be able to calculate 2 problem types:

a. specific heat problems b. heats of vaporization or fusion

DO NOW: 1. Given: 3.70 J and ΔT -21 ---> -41 Find: mass of water 2. Given: 2.25 mol methanol Find: kJ required to vaporize if at

-33.3 °C (bp of methanol)HOMEWORK: 1. None===========================================================BASKET: Journal 4/26 (What you learned, or relearned about

specific heat calcs and heats of vaporization and fusion)

Please check to see if you accidently put a "W" eraser in your backpack.

===========================================================

(for heat of vaporizaiton)

Specific Heat J/g°C

Given Find

J g °C

Heat of fusion kJ/mol

Given Find

kJ mol

Given Find

Heat of Vap kJ/mol

Who goes with What?

slopesflat lands

4.18 Jg °C

6.02 kJmol

40.6 kJmol

Make up problems for all 3 boxes above and work out in the box provided above.

J

g°C

slopesflat lands

kJmol

flat lands

kJmol

find

39.5 J

148 J

2.05 J

find

Specific heat - practice problems

2.5 kg

find

725 g

find

82 g

0°C ---> 32°C

100°C ---> 145°C

find

-82°C ---> -5°C

74°C ---> 30°C

Q# J mass ΔT

1

2

3

4

5

Pract. Probs. Ch 16.3 - Thermochem. Eqns.

Heat of Vaporization/Fusion - practice problems

5.5

find

find

1.7

find

find

22.5

83.1

find

2.6

water

ammonia (NH3)

methanol

ethanol

NH3

Q# mol kJsubstance

6

7

8

9

10

Name:_______________ Date:_______ Period:__Directions:

Show calcs!Answer questions next to each line, or number 1-10 on back and show calcs there with note on front to look at the back.

This page was use to make: http://mrwiggersci.com/chem/homework/Ch-16-3-PPs-sp-ht-vap-fusion.htm

1. Given: 3.70 J and ΔT -21 ---> -41 deg C Find: mass of water

0.0925 g H2O

2.0 J

g °Csp ht H2O solid

2. Given: 2.25 mol methanol Find: kJ required to vaporize if at -33.3

°C (bp of methanol)

Specific Heat & Heats of Fusion & Vap

Grade:«grade»

Subject:«subject»

Date:«date»

1 For specific heat problems, if you are given mass and J (joules), what will the find be?

A ΔT

B mol

C J

D g

2 For specific heat problems, if you are given mass and ΔT, what will the find be?

A ΔT

B J

C g

D mol

3 For Specific Heat problems, if you are asked to find ΔT what information must you be given to be able to solve the problem? (there may be more than one correct answer, choose all that apply, or none)

A J

B ΔT

C g

D mol

E all of these are needed

F none of these are needed

4 For heat of vaporization problems, if you are given grams of He, what will you need to do to solve the problem?

A use specific heat and solve for kJ

B change grams to moles and use heat of fusion to solve the problem

C change grams to moles and use heat of vaporization to solve the problem

D you cannot solve this problem

5/1/2013 Standards: 7 (Chemical Thermodynamics)Objectives: Students will be able to calculate 2 problem types:

a. specific heat problems b. heats of vaporization or fusion

DO NOW: 1. Classwork working problems from SmartBoardHOMEWORK: 1. Ch 16.2 p. 498 #12 & 13; Ch 16.3 p. 504 20, 21, 22 (5 pts) Std 7

(students will grade each others homework tomorrow)=========================================================== Journal 4/30 (What you learned, or relearned about

specific heat calcs and heats of vaporization and fusion)

TRY

Always look for what you did wrong first, be the leader!

Choose wisely!

Wife blows up at husband coming home after work

10 minmake trying a habitmarriage must be foreversex

happy wifehappy life

Specific Heat J/g°C

Given Find

J g °C

Heat of fusion kJ/mol

Given Find

kJ mol

Given Find

Heat of Vap kJ/mol

Who goes with What?

slopesflat lands

4.18 Jg°C

6.02 kJmol

40.6 kJmol

Make up problems for all 3 boxes above and work out in the box provided above.

Jg°C

slopeskJ mol

flat lands

kJmol

flat lands

/

40.6 kJmol

Specific Heat & Heats of Fusion & Vap

Grade:«grade»

Subject:«subject»

Date:«date»

1 For specific heat problems, if you are given mass and J (joules), what will the find be?

A ΔT

B mol

C J

D g

2 For specific heat problems, if you are given mass and ΔT, what will the find be?

A ΔT

B J

C g

D mol

3 For Specific Heat problems, if you are asked to find ΔT what information must you be given to be able to solve the problem? (there may be more than one correct answer, choose all that apply, or none)

A J

B ΔT

C g

D mol

E all of these are needed

F none of these are needed

4 For heat of vaporization problems, if you are given grams of He, what will you need to do to solve the problem?

A use specific heat and solve for kJ

B change grams to moles and use heat of fusion to solve the problem

C change grams to moles and use heat of vaporization to solve the problem

D you cannot solve this problem

vaporization

fusion

Q# J mass ΔT

Q# mol kJsubstance

2.50

find

find

44.0

water

ammonia (NH3

3

4

1

2

find

25.0 J

4.5 kg

find

0°C ---> 22°C

-60°C ---> -25°C

(Chart p. 502)

Both areH2O

Group practice - work in groups of 4. Copy the questions as given & find, and work out the answers using a series of fractions.

1. 414,000 J 3. 102 kJ2. 0.356g 4. 7.8 mol

ANSWERS

5/2/2013 Standards: 7 (Chemical Thermodynamics)Objectives: Students will be able to calculate 2 problem types:

a. specific heat problems b. heats of vaporization or fusion

DO NOW: 1. When HW papers returned, trade papers for grading. HOMEWORK:

1. Zum Heating Curve Questions 13-17 (bottom right) (5 pts) Std 7 2. Help Sheet for Mini Quiz Ch 16.1-16.3 (5pts) Std 7

===========================================================BASKET: Journal 5/1 (What you learned, or relearned about

specific heat calcs and heats of vaporization and fusion) 1. Ch 16.2 p. 498 Ch 16.3 #12 & 13; p. 504 20, 21, 22 (5 pts) Std 7

(students will grade each others homework tomorrow)5

Announcement quiz on

a. specific heat problems b. heats of vaporization or fusion

Tomorrow, Friday (5/3)

13. heat of vaporization

heat offusion

vaporization = 22 x fusion

for substance X

Homework answers for Th 5/2

14. melt 10.0 g of X = 0.48 kJvap 27 10.0 g of X = 27 kJ

15. 848 J melts 11.5 g H2O3,020 J vaporizes 11.5 g H2O

16. fuse 25.og H2O = 8.37 kJvap 37.5g H2O = 84.4 kJwarm H2O 55.2g 0 ---> 100°C 23.1 kJ

17. cool 10.0g H2O from 200°C ---> 100°C = 2.03 kJcondense 10.0g H2O = 22.50 kJcool 10.0g H2O from 100°C ------> 0°C = 4.18 kJfreeze 10.0g H2O =

3.34 kJcool 10.0g H2O from 0°C ------> -5.0°C = 1.03 kJ

-------------total energy removed from 10 g H2O going

from 200°C ---> -5.0°C 32.08 kJ

5/3/2013 Standards: 7 (Chemical Thermodynamics)Objectives: Check for understanding of:

a. specific heat problems b. heats of vaporization or fusion

DO NOW: 1. Prep. for Ch 16 Mini Quiz Ch 16.1, 16.2, 16.3 - polish your Help SheetHOMEWORK: NONE===========================================================BASKET: Journal 5/2 (What you learned, or relearned about

specific heat calcs and heats of vaporization and fusion) 1. Zum Heating Curve Questions 13-17 (bottom right) (5 pts) Std 7

For this period only, if you didn't do the homework last night, or didn't completeit, you may redo and turn in on Mon forfull credit.

Put papers into 5 stacks

Help Sheetsscratch

The following in order with smallest # on top:

quizzesscantroncharts

Spread so #'s show

ΔH = - 50kJ

°C

α

Δ

β

↑↓

Ω

ᵝ ᵦ