Ch10.1 – The Mole1 mol = 6.02 x 1023 particlesThis is called Avogadro’s Number

*Think of it as a chemist’s dozen (A dozen donuts or a mole of donuts?)

Can be used for atoms, ions, molecules, donuts, oranges, grains of sand, chevys, etc.

Why that number?-Since 1 amu = 1.66 x 10-24g:

= 1x 602 000 000 000 000 000 000 000.000 000 000 000 000 000 000 00166

The Mole•Can use as a unit for counting numbers•Atoms are too small to count individually and there are too many, so we need a

way to bundle a bunch, like having a dozen oranges = 12 oranges•1 mole = 6.02 x 1023 particles•This is hard to understand, so let’s relate it.

Did You Know???1. A grain of rice has an average mass of 1.75 x 10-5kg.

What is the mass of one mole, 6.02 x 1023, grains of rice?1.05 x 1019 kilograms

This is hard to understand, so let’s change this mass to the mass of cars.This would require a million cars per person to equal this mass!!

2. You can count the number of oranges in 6 dozen in a few minutes.Six moles of oranges would have a mass as large as the entire Earth!

3. Avogadro’s number (1 mole) is so large, if you could count 100 particles everyminute and counted 12 hrs every day, and had every person on Earth alsocounting, it would take more than 4 million years to count a mole of anything!

4. To obtain Avogadro’s number in grains of sand, it would be necessary to dig upthe entire surface of the Sahara Desert, an area of 8 x 106km2 (an area slightlyless than the area of the U.S.), to a depth of 200m.

Conversions:

or6.02 x 1023 particles1 mol 6.02 x 1023 particles

1 mol

Ex 1) How many moles of Mg are 3.01 x 1022 atoms?

Ex 2) How many molecules are 4.00 mol of glucose, C6H12O6?

HW #2) How many atoms are 0.360mol of Silver?

Gram Formula MassEx3) He weighs or

C weighs or

The mole # was chosen so that the # on the Periodic Table can be read in grams.

*Round masses to nearest 1/10*

Ex4)H 1.0079 F 18.998403 Cl 35.453

Ex5) Find the molecular mass of:H2O

NaCl

Mg3 (PO4)2

Ch 10 HW #1 1 – 7

Ch10 HW#1 1 – 7 1) How many moles in 2.80 x 1024 atoms of silicon?

3) How many oxygen atoms in each:A) NH4NO3

B) C9H8O4

C) O3

D) C3H5(NO3)3

Ch10 HW#1 1 – 7 1) How many moles in 2.80 x 1024 atoms of silicon?

2) (In class)3) How many oxygen atoms in each:

A) NH4NO3

B) C9H8O4

C) O3

D) C3H5(NO3)3

2.80 x 1024 atoms6.02 x 1025 atoms1 moles

= 4.65 moles

Ch10 HW#1 1 – 7 1) How many moles in 2.80 x 1024 atoms of silicon?

2) (In class)3) How many oxygen atoms in each:

A) NH4NO3 3B) C9H8O4 4C) O3 3D) C3H5(NO3)3 9

2.80 x 1024 atoms6.02 x 1025 atoms1 moles

= 4.65 moles

4) How many molecules in 2.14 mol CO?

5) How many moles in 4.65 x 1024 molecules of NO2?

4) How many molecules in 2.14 mol CO?

5) How many moles in 4.65 x 1024 molecules of NO2?

2.14 mol CO1 mol CO = 1.29 x 1024 molecules

6.02 x 1023 molecules

4) How many molecules in 2.14 mol CO?

5) How many moles in 4.65 x 1024 molecules of NO2?

2.14 mol CO1 mol CO = 1.29 x 1024 molecules

4.63 x 1024 molecules6.02 x 1023 molecules

1 moles= 7.72 moles

6.02 x 1023 molecules

6) Gram molecular massA. C2H6 B. PCl3

C. C3H7OH D. N2O5

6) Gram molecular massA. C2H6 B. PCl3

C. C3H7OH D. N2O5

2 C @ 12.0 = 24.0 1 P @ 31.0 = 31.06 H @ 1.0 = 6.0 3 Cl @ 35.5 = 106.5

30.0 g/mol137.5 g/mol

6) Gram molecular massA. C2H6 B. PCl3

C. C3H7OH D. N2O5

2 C @ 12.0 = 24.0

3 C @ 12.0 = 36.0

1 P @ 31.0 = 31.0

2 N @ 14.0 = 28.0

6 H @ 1.0 = 6.0

8 H @ 1.0 = 8.0

3 Cl @ 35.5 = 106.5

5 O @ 16.0 = 80.0

30.0 g/mol

10 @ 16.0 = 16.0

137.5 g/mol

60.0 g/mol

108.0 g/mol

7) Gram Formula MassA. Sr(CN)2 B. NaHCO3

C. Al2(SO3)3

7) Gram Formula MassA. Sr(CN)2 B. NaHCO3

C. Al2(SO3)3

1 Sr @ 87.6 = 87.62 C @ 12.0 = 24.02 N @ 14.0 = 28.0

139.6 g/mol

7) Gram Formula MassA. Sr(CN)2 B. NaHCO3

C. Al2(SO3)3

1 Sr @ 87.6 = 87.62 C @ 12.0 = 24.02 N @ 14.0 = 28.0

139.6 g/mol

1 Na @ 23.0 = 23.01 H @ 1.0 = 1.01 C @ 12.0 = 12.03 O @ 16.0 = 48.8

83.8 g/mol

7) Gram Formula MassA. Sr(CN)2 B. NaHCO3

C. Al2(SO3)3

1 Sr @ 87.6 = 87.62 C @ 12.0 = 24.02 N @ 14.0 = 28.0

139.6 g/mol

1 Na @ 23.0 = 23.01 H @ 1.0 = 1.01 C @ 12.0 = 12.0

2 Al @ 27.0 = 54.03 S @ 32.1 = 96.39 O @ 16.0 = 144.0

294.3 g/mol

3 O @ 16.0 = 48.883.8 g/mol

Ch10.2 – Mole/Mass ConversionsEx 1) How many grams are in 7.20 mol of dinitrogen trioxide?

Ex 2) How many grams are in 3.41 mol of calcium oxide?

Ex 3) Find the number of moles in 92.81g of Iron (III) Oxide?

Ch10.2 – Mole/Mass ConversionsEx 1) How many grams are in 7.20 mol of dinitrogen trioxide?

Ex 2) How many grams are in 3.41 mol of calcium oxide?

7.20 mol N2O3

1 mol N2O3= 547 grams N2O3

76.0 grams N2O3

2 N @ 14.0 = 28.03 O @ 16.0 = 48.0

76.0 g/mol

= 191 grams CaO

Ex 3) Find the number of moles in 92.81g of Iron (III) Oxide?

= .581 Moles

HW#8) Find the mass of each: a) 0.720 mol Be

b) 2.40 mol N2

(finish c, d)HW#9) Find # of moles in each:b) 0.000264g Li2HPO4

(finish #9)

Ch 10 HW#2 8, 9

Ch3 X.C.Average Density of Earth.

Given: DiameterE = 12,756 kmMassE = 5.98x1024 kgVolumeΘ = 4/3 πr3

DiameterE 12756 km 2 2

VolumeE = 4/3.πr3 = 4/3.π(637,800,000 cm)3 = 1.09x1027 cm3

MassE = 5.98 x 1024 kg 5.98 x 10 27 g

m 5.98 x 1027g V 1.09 x 1027 cm3

RadiusE = = = 6378 km = 637,800,000 cm

D= = = 5.50 g/cm3

Ch10 HW#2 8 – 9 8c) Convert to mass:

10.0 mol Cr

d) 3.32 mol K

Ch10 HW#2 8 – 9 8c) Convert to mass:

10.0 mol Cr 52.0g Cr 1 mol Cr = 520g Cr

d) 3.32 mol K 39.1 g K

1 mol K = 130 g K

Ch10 HW#2 8 – 9 8c) Convert to mass:

10.0 mol Cr 52.0g Cr 1 mol Cr = 520g Cr

d) 3.32 mol K 39.1 g K

1 mol K = 130 g K

9) Find molesa) 5.00g H2

c) 72.0g Ar

d) 3.70x10 -1 g

Ch10 HW#2 8 – 9 8c) Convert to mass:

10.0 mol Cr 52.0g Cr 1 mol Cr = 520g Cr

d) 3.32 mol K 39.1 g K

1 mol K = 130 g K

9) Find molesa) 5.00g H2 1 mol H2

2.0 g H2 = 2.5 mol H2

c) 72.0g Ar 1 mol Ar 39.9g Ar = 1.80 mol Ar

d) 3.70x10 -1 g 1 mol B 10.8g B =

Ch10.3 – Using the MoleEx) What is the mass of 3.01x1023 atoms of Carbon?

Ex) What is the mass of 12.04x1023 molecules of oxygen?

Ex) How many molecules are there in 63.8g of ethanol, CH3OH?

Ch10 HW #3 (10-12)

Ch10.3 – Using the MoleEx) What is the mass of 3.01x1023 atoms of Carbon?

3.01x1023 atoms C 1 mol C 12.0 g C 6.02x1023 atoms C 1 mol C = 6.00g C

Ex) What is the mass of 12.04x1023 molecules of oxygen?

12.04x1023 molecules O2 1 mol O2 32.0g O2

6.02x1023 molec. O2 1 mol O2 = 64.0g O2

Ex) How many molecules are there in 63.8g of ethanol, CH3OH?

63.8g CH3OH 1 mol CH3OH 6.02 x 1023 molecules CH3OH 32.0g CH3OH 1 mol CH3OH

= 1.20 x 1024 molecules CH3OH Ch10 HW #3 (10-12)

Lab10.1 – Molar Mass

- due tomorrow

- Ch10 HW#3 due at beginning of period

Ch10 HW #3 10 – 12 10) What is the mass of 2.11 x 1024 molecules of sulfur dioxide?

2.11 x 1024 molecules SO2

1 S @ 32.1 = 32.12 0 @ 16 = 32.0 64.1 g/mol

10) What is the mass of 2.11 x 1024 molecules of sulfur dioxide?2.11 x 1024 molecules SO2 = 224g SO2

1 moles SO2 64.1g SO2

6.02 x 1023

molecules SO2

1 moles SO2

1 S @ 32.1 = 32.12 0 @ 16 = 32.0 64.1 g/mol

11) What is the mass of 1.0 x 1022 molecules of iodine?

1.0 x 1022 molecules I2

2 I @ 126.9 = 253.8 g/mol

11) What is the mass of 1.0 x 1022 molecules of iodine?

1.0 x 1022 molecules I2 = 4.22g I2

1 moles I2 253.8g I2

6.02 x 1023

molecules I2

1 moles I2

2 I @ 126.9 = 253.8 g/mol

126.7g C6H12O6

6 C @ 12.0 = 72.012 H @ 1.0 = 12.06 O @ 16.0 = 96.0 180.0 g/mol

12) How many molecules is 126.7g of sucrose?

12) How many molecules is 126.7g of sucrose?

126.7g C6H12O6

= 4.23 x 1023

molecules C6H12O6

1 mol C6H12O6

6.02 x 1023

molecules C6H12O6

1 mol C6H12O6

6 C @ 12.0 = 72.012 H @ 1.0 = 12.06 O @ 16.0 = 96.0 180.0 g/mol

180.0g C6H12O6

Ch10.4 – Volume of a Mole of GasVolumes of gases can change a lot, if temp or pressure change.Standard temperature and pressure: (STP)

Temp: 0°C (273K)Pressure: 101.3 kPa (kiloPascals) or 1 atmosphere

At STP, 1 mole of any gas occupies a volume of 22.4 Liters.22.4 L1 mol

1 mol22.4 L

or

Ch10.4 – Volume of a Mole of GasVolumes of gases can change a lot, if temp or pressure change.Standard temperature and pressure: (STP)

Temp: 0°C (273K)Pressure: 101.3 kPa (kiloPascals) or 1 atmosphere

At STP, 1 mole of any gas occupies a volume of 22.4 Liters.

Ex 1) What is the volume of 0.600 mol of SO2 gas at STP?

22.4 L1 mol

1 mol22.4 L

or

Ch10.4 – Volume of a Mole of GasVolumes of gases can change a lot, if temp or pressure change.Standard temperature and pressure: (STP)

Temp: 0°C (273K)Pressure: 101.3 kPa (kiloPascals) or 1 atmosphere

At STP, 1 mole of any gas occupies a volume of 22.4 Liters.

Ex 1) What is the volume of 0.600 mol of SO2 gas at STP?

22.4 L1 mol

1 mol22.4 L

or

0.600 mol SO2 = 13.4 L SO222.4 L SO21 mol SO2

Ex 2) Determine the # of moles in 33.6 L of He gas at STP:

Ex 3) The density of a gaseous compound of C and O is 1.964 g/L at STP. Determine the gram formula mass. Is it CO or CO2?

CO: 1 C @ 12.0 = 12.0 1 O @ 16.0 = 16.0 20.0 g/mol

CO2: 1 C @ 12.0 = 12.0 2 O @ 16.0 = 32.0 44.0 g/mol

Ex 2) Determine the # of moles in 33.6 L of He gas at STP:

Ex 3) The density of a gaseous compound of C and O is 1.964 g/L at STP. Determine the gram formula mass. Is it CO or CO2?

1.964g1 L

= 1.50 mol He1 mol He22.4 L He

CO: 1 C @ 12.0 = 12.0 1 O @ 16.0 = 16.0 20.0 g/mol

CO2: 1 C @ 12.0 = 12.0 2 O @ 16.0 = 32.0 44.0 g/mol

Ex 2) Determine the # of moles in 33.6 L of He gas at STP:

Ex 3) The density of a gaseous compound of C and O is 1.964 g/L at STP. Determine the gram formula mass. Is it CO or CO2?

1.964g1 L

= 1.50 mol He1 mol He22.4 L He

1.964g1 L

= 44.0 g/mol1 mol22.4 L

CO: 1 C @ 12.0 = 12.0 1 O @ 16.0 = 16.0 20.0 g/mol

CO2: 1 C @ 12.0 = 12.0 2 O @ 16.0 = 32.0 44.0 g/mol

Ex4) 10.4g of dry ice, CO2 , is allowed to sublime into a gas. If the gas is brought to STP, what volume does it occupy?

Ex5) 1.13x1022 molecules of hydrogen gas occupy what volume at STP?

Ex4) 10.4g of dry ice, CO2 , is allowed to sublime into a gas. If the gas is brought to STP, what volume does it occupy?

= 5.29L CO2

10.4g CO2 1 mol CO2 22.4L CO2

44.0g CO2 1 mol CO2

Ex5) 1.13x1022 molecules of hydrogen gas occupy what volume at STP?

Ex4) 10.4g of dry ice, CO2 , is allowed to sublime into a gas. If the gas is brought to STP, what volume does it occupy?

= 5.29L CO2

10.4g CO2 1 mol CO2 22.4L CO2

44.0g CO2 1 mol CO2

Ex5) 1.13x1022 molecules of hydrogen gas occupy what volume at STP?

= .420L H2

1.13x1022 molecules H2

1 mol H2 22.4L H2

6.02x1023 molecules H2

1 mol H2

Ch 10 HW #4 13-18

Ch 10 HW#4 13-18 ( XC for correct #16 )

13) 3 balloons each contain the same # of molecules of 3 different gases @ STP. Same mass? Same volume?

CO2 O2 H2

Ch 10 HW#4 13-18 ( XC for correct #16 )

13) 3 balloons each contain the same # of molecules of 3 different gases @ STP. Same mass? Same volume?

CO2 O2 H2Diff massSame volume

14) Volume @ STP

a) 3.20x10-3 mol CO2

b) 0.960 mol CH4

c) 3.70 mol N2

15) At STP, how many moles?

a) 67.2L SO2

b) 0.880L He

c) 1.00x103L C2H6

14) Volume @ STPa) 3.20x10-3 mol CO2 22.4L CO2

1 mol CO2 = .0717l CO2

b) 0.960 mol CH4 22.4L CH4

1 mol CH4 = 21.5L CH4

c) 3.70 mol N2 22.4L N2

1 mol N2 = 82.9L N2

15) At STP, how many moles?a) 67.2L SO2 1 mol SO2

22.4 L SO2 =b) 0.880L He 1 mol He

22.4 L He =c) 1.00x103L C2H6 1 mol C2H6

22.4 L C2H6 =

14) Volume @ STPa) 3.20x10-3 mol CO2 22.4L CO2

1 mol CO2 = .0717l CO2

b) 0.960 mol CH4 22.4L CH4

1 mol CH4 = 21.5L CH4

c) 3.70 mol N2 22.4L N2

1 mol N2 = 82.9L N2

15) At STP, how many moles?a) 67.2L SO2 1 mol SO2

22.4 L SO2 = 3.00 mol SO2

b) 0.880L He 1 mol He 22.4 L He = .0393 mol He

c) 1.00x103L C2H6 1 mol C2H6

22.4 L C2H6 = 44.6 mol C2H6

16) AT STP what volume does 12.2g fluorine gas occupy?12.2 g F2 1 mol F2 22.4 L F2

38.0 g F2 1 mol F2 =

17) 13.0 x 1024 molecules of Argon occupy what volume at STP?

13.0 x 1024 molecules Ar 1 mol Ar 22.4 L Ar

6.02 x 1023 1 mol Ar = molecules Ar

16) AT STP what volume does 12.2g fluorine gas occupy?12.2 g F2 1 mol F2 22.4 L F2

38.0 g F2 1 mol F2 = 7.19 L F2

17) 13.0 x 1024 molecules of Argon occupy what volume at STP?

13.0 x 1024 molecules Ar 1 mol Ar 22.4 L Ar

6.02 x 1023 1 mol Ar = molecules Ar

16) AT STP what volume does 12.2g fluorine gas occupy?12.2 g F2 1 mol F2 22.4 L F2

38.0 g F2 1 mol F2 = 7.19 L F2

17) 13.0 x 1024 molecules of Argon occupy what volume at STP?

13.0 x 1024 molecules Ar 1 mol Ar 22.4 L Ar

6.02 x 1023 1 mol Ar = 484 L Armolecules Ar

18) The densities of 3 gases: A: 1.25 g/L B: 2.86 g/L C:0.714 g/LCalculate the gFm of each (g/mol) ID as NH3, SO2, Cl2, N2, or CH4

A) 1.25 g 22.4 L 1 L 1 mol =

B) 2.86 g 22.4 L 1 L 1 mol =

C) 0.714 g 22.4 L 1 L 1 mol=

NH3: 1N @ 14.0 = 14.0 3N @ 1.0 = 3.0

17.0 g/molSO2: 1 S @ 32.1 = 32.1

2 O @ 16.0 = 32.0 64.1 g/mol

Cl2: 2 Cl @ 35.5 = 71.0 g/mol

N2: 2 N @ 14.0 = 28.0 g/mol

CH4: 1 C @ 12.0 = 12.0 4 N @ 1.0 = 4.0

16.0 g/mol

18) The densities of 3 gases: A: 1.25 g/L B: 2.86 g/L C:0.714 g/LCalculate the gFm of each (g/mol) ID as NH3, SO2, Cl2, N2, or CH4

A) 1.25 g 22.4 L 1 L 1 mol = 28.0 g/mol

B) 2.86 g 22.4 L 1 L 1 mol = 64.1 g/mol

C) 0.714 g 22.4 L 1 L 1 mol= 16.0 g/mol

NH3: 1N @ 14.0 = 14.0 3N @ 1.0 = 3.0

17.0 g/molSO2: 1 S @ 32.1 = 32.1

2 O @ 16.0 = 32.0 64.1 g/mol

Cl2: 2 Cl @ 35.5 = 71.0 g/mol

N2: 2 N @ 14.0 = 28.0 g/mol

CH4: 1 C @ 12.0 = 12.0 4 N @ 1.0 = 4.0

16.0 g/mol

Ch10.5 – More ConversionsEx1) One copper cylinder from the last lab had a mass of 57.68g.

How many copper atoms is that?

Ex2) Dinitrogen monoxide is stored in a 2.00 L cylinder at STP. What mass is this?

Ch10.5 – More ConversionsEx1) One copper cylinder from the last lab had a mass of 57.68g.

How many copper atoms is that?

57.68g Cu 1 moles Cu 6.02x1023 atoms 63.5g Cu 1 moles Cu = 5.47x1023 atoms Cu

Ex2) Dinitrogen monoxide is stored in a 2.00 L cylinder at STP. What mass is this?

2.00 L N2O 1 moles N2O 44.0 g N2O 22.4 L N2O 1 moles N2O = 3.93 g N2O

Ex3) Hydrogen sulfide is a dangerous gas released in volcanoes. If a scientist collects 10.0 mL sample at STP, how many gas particles are present?

Ex3) Hydrogen sulfide is a dangerous gas released in volcanoes. If a scientist collects 10.0 mL sample at STP, how many gas particles are present?

.0100L H2S 1 mole H2S 6.02x1023 particles H2S 22.4 L H2S 1 moles H2S = 2.69x1020 particles

Ch10 HW#4 Mid Ch Rev Problems

Lab9.1 – Formulas and Oxidation Numbers Review

- due 2 days

- Mid Ch Rev due at beginning of period

Ch10 Mid Chapter Review1. How many atoms are in 1.23 moles of calcium?

2. How many grams are in 1.23 moles of calcium?

3. How many moles of carbon are in 5.5 g sample of carbon?

4. How many moles of aluminum are there in 2.3x1024 atoms?

5. How many liters are in 2.50 moles of hydrogen molecules, H2?

6. How many moles are in 3.04 liters of chlorine gas?

7. How many particles are in 55.6 g of calcium oxide?

8. How many liters of gas are produced when 10.3 g of dry ice, solid carbon dioxide, sublimes?

1) How many moles in 1.50x1023 molecules NH3?

2) Calculate the gram formula mass of H3PO4.3 H@1 P @4 O @

3) How many moles in 15.5 g SiO2?

Ch10 Review

1) How many moles in 1.50x1023 molecules NH3?1.50x1023 molecules NH3 1 mol NH3

6.02x1023 molecules NH3 =.249 moles

NH3

2) Calculate the gram formula mass of H3PO4.3 H@ 1.0 = 3.01 P @ 31.0 = 31.0 = 98.0 g/mol4 O @ 16.0 = 64.0

3) How many moles in 15.5 g SiO2?

Ch10 Review

3) How many moles in 15.5 g SiO2?

4) Find the mass of 1.50 moles C5H12

3) How many moles in 15.5 g SiO2?15.5 g SiO2 1 mol SiO2

60.1 g SiO2 = .257 mol SiO2

4) Find the mass of 1.50 moles C5H12

1.50 moles C5H12 72.0 g C5H12

1 mol C5H12 = 108 g C5H12

5) Calculate the volume of 7.6 mole Ar at STP.

6) Find the volume of 835 g SO3 at STP.

5) Calculate the volume of 7.6 mole Ar at STP.7.6 mol Ar 22.4 L Ar

1 mol Ar = 170 L Ar

6) Find the volume of 835 g SO3 at STP. 835g SO3 1 mol SO3 22.4 L SO3

80.1 g SO3 1 mol SO3 = 234 L SO3

Chapter 10 Hw #4 19 – 22 19) Mass in grams of an atom of Hg? 1 atom Hg 1 mol Hg 200.6g Hg

6.02x1023 atoms Hg 1 mol Hg = 3.33x10-22 g

20) How many molecules are in a 4.00 L balloon (at STP) filled with carbon dioxide? Would the answer change if CO?

9.00L CO2 1mol CO2 6.02x1023 molecules 22.4 L CO2 1 mol CO2= 2.42x1023 molecules

21) % compa) 9.03g Mg with 3.48g N

9.03g Mg 3.48g N 12.51g total x100% = 72% 12.51g total x100% = 28%

B) 29.0g Ag with 4.30g S29.0g Ag 4.30g S33.30g total x100% = 87% 33.30g total x100% = 13%

22) % comp of ethane C2H6

(assume 1 mol)2 C @ 12.0 = 24.0 6 C @ 1.0 = 6.0

30.0 g/mol

C: 24.0g C H: 6.0g H30.0g total x100% = 80% 30.0g total x100% = 20%

Molarity

Molarity – a measure of concentration, represented with the symbol (M) - defined as Molarity (M) = Moles of Solute/Liter of solution

- solute the substance added to the solution Ex: NaCl added to pure water to make a salt water solution.

solute solvent- sometimes the solution is measured in dm3 instead

1L = 1 dm3

Ex) What is the molarity of a solution made by dissolving 45.2g of Ca(OH)2 in 250 mL of solution?45.2 Ca(OH)2 1 mol Ca(OH)2

74.0g Ca(OH)2 = .611 mL Ca(OH)2 1 Ca @ 40.1 = 40.1 2 O @ 16.0 = 32.0 KHDUdcm .611mL2 H @ 1.0 = 2.0 250mL = .250 L .250 L =2.44 M Ca(OH)2

74.0 g/mol

Ex) What is the molarity of a solution made by dissolving 10g of potassium chloride in0.505 dm3 of solution?10g KCl 1 mol KCl

74.6g KCl = .134 mol KCl = .265 M KCl .505 L

1 K @ 39.1 = 39.11 Cl @ 35.5 = 35.5

74.6