UNITS BASICS OF CHEMISTRY PART 3/3 MOLAR MASS? If ATOMS? 08 Molar mass is the mass of molar mass = mass of one mole particles/atom/ 6.022 X 1023 atoms molecule/ion. which is 09 Molar mass is measured g/mol GRAM ATOMIC MASS in grams per mole = GAM

10 (g/mol). UNITS molar mass 11 SI SI If MOLECULE? If GASES? molar mass = mass of Gaseous molar volume 12 6.022 X 1023 molecules = Volume of which is 6.022 X 1023 molecules 13 GRAM MOLECULAR = 22.4L @ STP MASS (1 atm, 273K) 14 CHEMISTRY = GMM Note: The molar mass in grams is numerically equal to atomic/molecular mass in (u). Molar Mass Calculation: 08 Calculate the molar mass of the 09 Glucose (C H O ) g/mol 6 12 6 10 UNITS Molar Mass of H = 1 g.mol-1 molar mass 11 Molar Mass of C = 12 g.mol-1 SI SI Molar Mass of O = 16 g.mol-1 12

13 Molar Mass of C6H12O6

14 = 6(12) + 12(1) + 6(16) CHEMISTRY = 72 + 12 + 96 = 180 g.mol-1 If Molecular Formula Of When Compound Compound Is Known, One Can Is Formed From Two Or 08 Calculate The Mass Percentage More Elements, The Of Element Present In That Amount Of Element Compound. In Contrast To This, Present In A Compound 09 If One Knows The Mass Is Always Proportional Percentage Of All Elements To Its Definite % Present In A Compound, Its Mass. 10 Molecular Formula Can UNITS Be Determined.

Mass % of 11 SI SI element 12 Percentage Composition Of An Element 13 Mass % Of An Element 14 CHEMISTRY = 풎풂풔풔 풐풇 풕풉풆 풆풍풆풎풆풏풕 풊풏 풕풉풆 풄풐풎풑풐풖풏풅 ×ퟏퟎퟎ 풎풐풍풂풓 풎풂풔풔 풐풇 풄풐풎풑풐풖풏풅 Calculate The Percentage Of Each

Element Present In Ethanol (C2H5OH). 08 Solution :

09 Atomic mass of C = 12.0 gram mole-1 % Atomic mass of H = 1.0 gram mole-1

10 Atomic mass of O = 16.0 gram mole-1 UNITS

Mass % of 11 Molecular mass of ethanol (C2H5OH) SI SI = 2(12) + 6 (1) +1 (16) element 12 = 24 + 6 + 16 = 46 gram mole-1 13 Mass % of H = 6 x 100 = 13.03% 14 46 Mass % of C = 2(12) x 100 = 52.17% CHEMISTRY 46 Mass % of O = 1(16) x 100 = 34.78% 46 PERCENTAGE BY WEIGHT

%w/w, 08 %w/v It Is The 09 Expression Of %w/w Concentration %w/v Of Solute In

10 Solution UNITS

percent by 11 SI SI weight 12

13

14 CHEMISTRY %w/w? The Weight Of Formula Substance In Gram %w/w = 08 Dissolved In 100 Gram Solution Is Called 풘풆풊품풉풕 풐풇 풔풐풍풖풕풆 푿 ퟏퟎퟎ Percentage By Weight 풘풆풊품풉풕 풐풇 풔풐풍풖풕풊풐풏 풊풏 품풎 %w/w 09 (%w/w). It Stands For Weight Per %w/v Weight

10 EXAMPLE UNITS In How Many Grams Of Water 36.5 gram HCl Should

percent by 11 Be Dissolved So That 10% w/w Solution Will Be SI SI Obtained? weight 12 Total Weight Of Solution = M g, Weight of Solute (HCl) = 36.5 gm, 13 w/w% = 10% %w/w = ퟑퟔ.ퟓ 푿 ퟏퟎퟎ = 10% 14 퐌 CHEMISTRY Total Weight Of Solution M = ퟑퟔ.ퟓ 푿 ퟏퟎퟎ = 365 gm ퟏퟎ

Weight Of Water = 365 – 36.5 = 328.5 gm H2O . %w/v? Formula The Weight Of Substance In %w/v = 08 Gram Dissolved In 100 Ml Solution Is Called Percentage 풘풆풊품풉풕 풐풇 풔풐풍풖풕풆 푿 ퟏퟎퟎ By Weight By Volume 09 (%w/v). 풗풐풍풖풎풆 풐풇 풔풐풍풖풕풊풐풏 풊풏 푳 %w/w It Stands For Weight Per Volume. %w/v 10 UNITS Example: percent by 11 How Many Grams of NaOH Will Be Will Be Required To SI SI Prepare 500 ml Solution Containing 5% w/v NaOH ? weight 12

Ans.: %w/v = 풘풆풊품풉풕 풐풇 풔풐풍풖풕풆 푿 ퟏퟎퟎ = 5 % 13 ퟓퟎퟎ

14 Weight of Solute = ퟓ 푿 ퟓퟎퟎ = 25 gm CHEMISTRY ퟏퟎퟎ Weight of Solute = 25 gm %v/v Formula 08 The Volume Of Substance In ml Dissolved In 100 ml %v/v = Solution Is Called Percentage 푽풐풍풖풎풆 풐풇 풔풐풍풖풕풆 푿 ퟏퟎퟎ 09 By Volume (%v/v). 푽풐풍. 풐풇 풔풐풍풖풕풊풐풏 풊풏 풍풊풕. %v/v It Stands For Volume

10 Per Volume UNITS

percent by 11 EXAMPLE SI SI 2 L ethanol solution volume 12 have 200 ml ethanol then find out % v/v. 13 ퟐퟎퟎ 푿 ퟏퟎퟎ %v/v = ퟐퟎퟎퟎ 14 = 10%v/v CHEMISTRY Note: This is used when both chemicals in a solution are liquid. What Is “Mole Fraction” The ratio of the moles of any component to the total moles in a solution is the mole fraction. 08 퐦퐨퐥퐞 퐟퐫퐚퐜퐭퐢퐨퐧 퐨퐟 퐜퐨퐦퐩퐨퐧퐞퐧퐭

풎풐풍풆 풐풇 풄풐풎풑풐풏풆풏풕 09 = 풏풖풎풃풆풓 풐풇 풕풐풕풂풍 풎풐풍풆풔 풐풇 풄풐풎풑풐풏풆풏풕풔 풊풏 풂 풔풐풍풖풕풊풐풏

10 NOTE: UNITS The sum of the mole fraction of all the

mole fraction 11 components in a solution is always equal to 1. SI SI

Nos. of Moles of Solute A = nA 12 Nos. of Moles of Solvent B = nB

Total Nos. of Moles of Solution = nA + nB 13 풏 푴풐풍풆 푭풓풂풄풕풊풐풏 풐풇 푺풐풍풖풕풆 푨 = 푨 풏푨 + 풏푩 14 풏 CHEMISTRY 푴풐풍풆 푭풓풂풄풕풊풐풏 풐풇 푺풐풍풖풕풆 푩 = 푩 풏푨 + 풏푩 Mole Fraction Calculation Example 08 Find the Mole Fraction Of Water In A Solution When 13.8g NaCl Is Dissolved In 132 ml (g) Of Water. 09 Ans.: 10

UNITS Molar Mass of NaCl = 23 + 35.5 = 58.5 g/mol

mole fraction 11 Mole Of NaCl = ퟏퟑ.ퟖ = 0.2358 mol SI SI ퟓퟖ.ퟓ Molar Mass Of H O = 2 + 16 = 18 g/mol 12 2 Mole Of Water = ퟏퟑퟐ = 7.3333 13 ퟏퟖ Total moles of Solution = 0.2358 + 7.3333 14 = 7.5691 mol ퟕ.ퟑퟑퟑퟑ CHEMISTRY Mole Fraction of Water = = 0.9688 ퟕ.ퟓퟔퟗퟏ What Is “Molarity”?

When One gram mole Of A 08 One litre Of Solution Solute Is Dissolved In Containing One gram Solvent & Then Making mole Of A Substance Is 09 One litre Of Solution It Is OR Called 1 molar (1 M) Called One molar M Solution

10 (1M) solution. UNITS molarity 11 Molarity or molar SI SI concentration Is The Number Of moles Of 12 Solute In 1 litre Of Solution Other 13 SI Unit Units mol/lit 14 M, OR CHEMISTRY mol/dm3 mol/m3 Molarity Formulas 08 Molarity (M) = 푵풐. 풐풇 풎풐풍풆풔 풐풇 풔풐풍풖풕풆 09 푽풐풍풖풎풆 풐풇 풔풐풍풖풕풊풐풏 풊풏 풍풊풕풓풆 M (here volume is in litre)

10 UNITS

molarity 11 푵풐. 풐풇 풎풐풍풆풔 풐풇 풔풐풍풖풕풆 × ퟏퟎퟎퟎ SI SI Molarity (M) = 푽풐풍풖풎풆 풐풇 풔풐풍풖풕풊풐풏 풊풏 풎풍 12 (here volume is in ml) 13

푴풂풔풔 풐풇 풔풐풍풖풕풆 × ퟏퟎퟎퟎ 14 Molarity (M) = CHEMISTRY 푮푴푴 × 푽풐풍풖풎풆 풐풇 풔풐풍풖풕풊풐풏 풊풏 풎풍 (here volume is in ml) Molarity Calculation Example A Solution Prepared Using 15 g Of Sodium 08 Sulphate. The Volume Of The Solution Is 125 ml. Calculate The Molarity Of The Given 09 Solution Of Sodium Sulphate. M Solution:

10 UNITS GMM of Na2SO4 = 2(23) + 32 + 4(16) molarity 11 SI SI = 46 + 32 + 64 12 = 142 g/mol

13 Molarity (M) = 푴풂풔풔 풐풇 풔풐풍풖풕풆 × ퟏퟎퟎퟎ 푮푴푴 × 푽풐풍풖풎풆 풊풏 풎풍 14 = ퟏퟓ × ퟏퟎퟎퟎ CHEMISTRY ퟏퟒퟐ × ퟏퟐퟓ = 0.85 M What Is “Molality”?

One Mole Of 08 A Solute, When The Number Of Dissolved In One Moles Of Solute Dissolved In 1 kilogram Of The Solvent OR 09 kilogram Of Is Called One molal (m) Solvent. m Solution Or molality Of 10 Solution Is 1 m UNITS (1 molal).

molality 11 SI Unit SI SI mol/kg 12 A Solution Containing 13 3 moles Of Solute per kilogram Of Other Units Solvent For Example, 14 Is Said To Be molal CHEMISTRY 3 molal or 3 m m Molality Formulas 08 Molality (m) = 푁표. 표푓 푚표푙푒푠 표푓 푠표푙푢푡푒 09 푀푎푠푠 표푓 푠표푙푣푒푛푡 푖푛 푘푔. m

10 (here weight is in kg.) UNITS

molality 11 SI SI Molality (m) = 푁표. 표푓 푚표푙푒푠 표푓 푠표푙푢푡푒 × 1000 12 푀푎푠푠 표푓 푠표푙푣푒푛푡 푖푛 푔푟푎푚 (here weight is in gram) 13

Molality (m) = 푀푎푠푠 표푓 푠표푙푢푡푒 × 1000 14 퐺푀푀 × 푀푎푠푠 표푓 푠표푙푣푒푛푡 푖푛 푔푟푎푚. CHEMISTRY (here weight is in gram) Molality Calculation Example What is the molality of a solution containing 08 5.0 g NaCl dissolved in 25.0 g water?

09 Solution: m

10 Molar mass of NaCl = 23 + 35.5 UNITS

molality 11 = 58.5 g/mol SI SI molality (m) = 푀푎푠푠 표푓 푠표푙푢푡푒 × 1000 12 퐺푀푀 × 푀푎푠푠 표푓 푠표푙푣푒푛푡 푖푛 푔푟푎푚. (in this example solute = NaCl, solvent = water) 13 = 5 × 1000 14 58.5 × 25 CHEMISTRY = 3.42 m 01 MOLAR MASS UNITS 02 MASS % OF ELEMENT 03 PERCENT WEIGHT BASICS OF CHEMISTRY

04 PERCENT VOLUME

END OF 05 MOLE FRACTION PART 3/3 06 MOLARITY

07 MOLALITY SUMMARY 01 UNITS 08 WEIGHT

02 METRIC SYSTEM 09 VOLUME

03 SI UNITS 10 DENSITY

04 IUPAC 11 TEMPERATURE

05 IUPAP 12 ATOMIC MASS

06 UNIT PREFIXES 13 MOLECULAR MASS

07 MASS 14 MOLE CONCEPT SUMMARY 15 MOLAR MASS

16 MASS % OF ELEMENT

17 PERCENTAGE BY WEIGHT

18 PERCENTAGE BY VOLUME

19 MOLE FRACTION

20 MOLARITY

21 MOLALITY SUMMARY THANK YOU VERY MUCH