Chemistry Week

24

Please get out your Classwork and

calculator!

Feb 27th, 2013

AGENDA:1 – Agenda Bell Ringer2 – Notes: Mole

Conversion: 2 step conversions

3 – Work Time

Today’s Goal:Students will be able to

convert between moles, grams and particles.

Homework1. Mole Conversions

Wkst 2 – due tomorrow! (change to classwork assignment)

2. Work from Week 23 due by Friday

Wednesday, February 27

Objective: Students will be able to convert between

moles, grams and particles.

Bell Ringer: How many grams are in 3.75 moles

of H2SO4?

2 MINUTES REMAINING…

Wednesday, February 27

Objective: Students will be able to convert between

moles, grams and particles.

Bell Ringer: How many grams are in 3.75 moles

of H2SO4?

1 MINUTES REMAINING…

Wednesday, February 27

Objective: Students will be able to convert between

moles, grams and particles.

Bell Ringer: How many grams are in 3.75 moles

of H2SO4?

30 seconds Remaining…

Wednesday, February 27

Objective: Students will be able to convert between

moles, grams and particles.

Bell Ringer: How many grams are in 3.75 moles

of H2SO4?

10 seconds Remaining…

BELL-RINGER TIME IS

UP!

Feb 27th, 2013

AGENDA:1 – Agenda Bell Ringer2 – Notes: Mole

Conversion: 2 step conversions

3 – Work Time

Today’s Goal:Students will be able to

convert between moles, grams and particles.

Homework1. Mole Conversions

Wkst 2 – due tomorrow! (change to classwork assignment)

2. Work from Week 23 due by Friday

Wednesday, February 27

Objective: Students will be able to convert from

moles to grams and moles to particles.

Bell Ringer: How many grams are in 3.75 moles

of H2SO4?

Molar mass of H2SO4 = 98.1 g/mol.3.75 moles x 98.1 grams =

1 mole

3.75 x 98.1 g

= 367.9 g

Mole Conversions

Topic: Mole Conversions Part 2 Date: 2/26/2013 Yesterday mole to gram conversions

Example: If you have an 8.0 mole sample of NaCl, how many grams do you have?

1. NaCl =Na =Cl = 58.44 g

1 mol

1x+______1x

2. 8.0 mole NaCl x 58.44 g

1 mol

= 467.52 g NaCl

22.9935.45

= 22.99= 35.45

What if you were given a 200 g sample of NaCl, and you wanted to convert to moles?

Molar Mass of NaCl =

200 g

Gram to Mole

58.44 g

1 mole

x 1 mole =

58.44 g

200 mole =58.44

3.42 mol NaCl

mole gram

multiplication

gram mole

division

1 mole

58.44 g

=

Gram to Mole (cont)

Example: If you have a 150 g sample of AlPO4, how

many moles do you have?

1. AlPO4 =Al =P =O = 121 g

mol

1 x

+1 x

2. 150 g x 1 mol 121 g

= 1.24 mol AlPO4

2631

= 26= 31

4 x 16 = 64

Mole to Particle Conversion Conversion

YESTERDAY Imagine if you want to know HOW

MANY atoms are in 1.5 moles of silver metal…

1.5 moleX 6.02 x

1023 1 mole

= 9.03 x 1023 atoms

What if you were given a 2.00 x 1026 particles sample of NaCl, and you wanted to convert to moles?

2.00x 1026 particles

Particle to Mole

x 1 mole =

6.02 x 1023 part

2.00 x 1026 mole 6.02 x 1023

3.32 x 102 mol NaCl

mole particles

multiplication

particles mole

division

Problem Solving Decision Tree

Read the problem

If moles and grams

Calculate Molar Mass

If moles grams

If moles and particles

Multiply by molar mass

If grams moles

Divide by molar mass

If moles particles

Multiply by6.02 x 1023

If particles moles

Divide by6.02 x 1023

Mole to Gram Conversion

Imagine if you want to measure out a 1.5 mole sample of silver metal…? Could you count out 1.5 moles? But you can use molar mass to convert

moles to grams, and you can measure grams.

Molar Mass of Silver =

1.5 mole

107.9 g Ag

1 mole Ag

... NO!

x 107.9 g = 1 mole

1.5 x 107.9 g =

161.8 g Ag

Practice Problems

If you had a 7.5 mole sample of H2O, how many grams would you have?1. Determine the molar mass.2. Convert! (Watch units!)

1. H2O =2xH =O =

18.0 g 1 mol

(2 x 1.0)+ 16.0

2. 7.5 mole H2O x 18.0 g

1 mol= 7.5 x 18.0 g H2O

= 135.0 g H2O

What if you were given a 200 g sample of NaCl, and you wanted to convert to moles?

Molar Mass of NaCl =

200 g

Gram to Mole

58.5 g

1 molex 1 mole

=

58.5 g

200 mole =58.5

3.4 mol NaCl

mole gram

multiplication

gram mole

division

1 mole

58.5 g

=

What if you were given a 2.00 x 1026 particles sample of NaCl, and you wanted to convert to moles?

2.00x 1026 particles

Particle to Mole

x 1 mole =

6.02 x 1023 part

2.00 x 1026 mole 6.02 x 1023

= 3.32 x 102 mol NaCl

mole particles

multiplication

particles mole

division