Part 1 Concentration Expression PDF
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This document discusses solutions, focusing on nonelectrolytes, and various concentration expressions like molarity, molality, and normality. It details physical properties of solutions and provides examples.
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PART 1 CONC. EXPRESSION Good day. I'll be discussing about solutions of nonelectrolytes. So let us first define what do we mean by solution. Solution is defined as a chemical and physically homogeneous mixture of 2 or more substances, and those substances are your solute and solvent. Later, we will...
PART 1 CONC. EXPRESSION Good day. I'll be discussing about solutions of nonelectrolytes. So let us first define what do we mean by solution. Solution is defined as a chemical and physically homogeneous mixture of 2 or more substances, and those substances are your solute and solvent. Later, we will get to know more about what solute and solvent is and what is nonelectrolyte. So the learning objectives or learning outcomes, at the end of this unit, the student is expected to demonstrate knowledge and expressing different concentrations of solution, solve solve problems related to concentration expression. So for the outline, the definition of terms, the computations for expressions on concentrations, such as molarity, molality, normality, percentage expression, milliosmoles, and mole fraction. So for the definition of terms, let us first define what is a system. A system is generally considered to be a bonded space or an exact quantity of material substance. So a good example of a system or one phase system in, 2 or more phase system. So see, one phase system example true solutions are your molecular dispersion. When we say 2 or more, phases system, these are your course and your colloidal dispersion. Next, let us, define what are the physical properties of the system. So let me annotate. The physical properties of the systems are as follows. The first would be the additive property. Additive property, this depends on the sum of the individual properties of the component present in the system. Again, this depends on the sum of the individual properties of the components present in the system. So a good example of that would be molecular weight. So how do we compute for the molecular weight? So let's have an example. Sodium chloride. See, sodium chloride, to get for the molecular weight, you will get the atomic weight of your chlorine and your sodium, and then you will add it up. So you will get the molecular weight. So, it's a good example of an additive property. Sodium is 23, and then chlorine is, is 30, 35.5. Kyasha I, 58.5. Okay. So that is a good example of your additive property. The second is your constitutive property. When we say constitutive property, this depends on the type and arrangement of components in a system. Again, this depends on the type and arrangement of components in a system. So we have what we call your optical rotations. So see optical rotations leborotatory, dextrorotatory, and a good instrument used to measure that would be your polarimeter. Next would be c, refractive index. So refractive index, to measure that, we will use refractometer. Refractive index, a good example, refractometer. Good example of that is you you have a glass of water, and then you put your pencil, then bending of light. It's a good example of constituent our constitutive property. 3rd and last type of physical properties of the system would be the colligative property. Colligative property is a property that depends on the number of components in the system. K. Number of components in a system. So under colligative property, we have 4. K? These are your vapor pressure lowering, boiling point elevation, freezing point depression, and osmotic pressure lowering. K? So the those are a good example of your colligative property. Next, we have 2 types of your, properties of the system. So, again, we have 2 types of property of a system. We have what we call your extensive property or also known as your extrinsic property, and then we have your intensive property or your intrinsic property. K? When we say extensive property, this depends on the size and the amount of the material in the system. Depends on the size and the amount of this the materials in the system. So a good example of that would be your mass, length, volume, your enthalpy, your entropy, k, your electrical resistance. So those are a good example of your extensive property of the system. Size amount material. Okay? Okay. System intensive property This does not depends on the amount and the size of the material. Okay? Size and the amount of material. A good example of that would be your, viscosity. So this is the symbol for viscosity, density, temperature. K? Viscosity density, temperature, your velocity, and your specific gravity. So specific gravity Okay. So value. So dependent on amount or size material mode system. Next is the dispersion. So, see, dispersion, this is defined as it consists at least 2 phase with 1 or more dispersed internal phase and contain in a single, continuous, or external phase. So if you recall, your internal phase is also termed as your solute and your external phase as is your solvent. So we have 3 types of disperses, and these are your molecular dispersion, your coarse dispersion, and your colloidal dispersion. When we say molecular dispersion or true solution, the particle size is less than 1 nanometer. When we say colloidal dispersion, this is from 1 nanometer to 0.5 micrometer. And lastly, when we say coarse dispersion, this is greater than 0.5 micrometer. Next are face. Face are distinct homogeneous part of the system separate by definite boundaries from 1 odd from other parts of the system. When we say face, these are your solute. This is could be either your solute or your solvent. So when we look at the microscope, even if it's molecular dispersion or true solution, there are still boundaries for the solute and solvent, which are not so small visible. So true solutions are defined as 2 or more components that form homogeneous molecular dispersion. So by definition, solution is a mixture of 2 or more substance in a single phase. But as mentioned, when you look at the, when you look at the microscope, those solute are well distributed solvent. It was not visible enough by the naked eye. K? So one or one constituent is usually regarded as your solvent, and the other is your solute. So when we say your solute, this is your dissolving substance, and your solvent would be your dissolving medium. So a good example would be when you, when you mix water with coffee, so it's a good example of solution. You have there your solute, which is your coffee, and then your solvent is your water. So the mixture is termed as your solution. So these are, table example solutions. Okay? Physical pharmacy solution. I see. Air. So Simpli Solutions Air. So next. So there are 3 definitions of solution, and it can be classified as saturated solution. When we say saturated solution, it contains maximum quantity of solute that dissolve at a given temperature. Usually, solute is at equilibrium solvent. So equal at equilibrium given temperature. Saturated unsaturated. Unsaturated solvent high solute. Supersaturated solute high solvent. So classy, mixture. Usually, ionic compound, could be soluble in water. Intermolecular forces, ionic compounds are soluble with polar, and thus mentioned, your water is highly polar. That is why you can produce an aqueous mixture. So a good example of that is your potassium permanganate and water. So many reaction involve ionic compounds, especially the reaction with water is termed their aqueous. Use. Potassium permanganate, water ionization ions and ions separate potassium permanganate potassium permanganate ionization potassium and then as well as your permanganate, positive ion and then negative ion So cationic and anionic which are your ionic compounds soluble with water. So classify solute. Non electrolytes, 10 year electrolytes. When we say nonelectrolyte, they are the substance that do not ionize when dissolved in water. Ionize charges conduction electricity or current to the solution. Unlike electrolyte that they form an ions and a solutions. So there is an electric current and show an shown an apparent, anomalous colligative property. So later, maintain class electrolytes. Compounds electric current charges. But partially ionized. So later, we will discuss each. So a good example of those are your aqueous solution. How do you know the ions are present in aqueous solution? There are called electrolytes. So we have your strong electrolytes. These are compounds which are completely ionized. When you add that to water, okay, it will conduct an electric current, which means, completely ionized. So a good example of that would be, see, hydrochloric acid, magnesium chloride, sodium chloride, sulfuric acid. Okay. Sodium hydroxide water ionize sodium. Plus, hydroxide, so again, complete ionized. Partially ionized or weak electrolytes, most drugs, okay, such as, epiderine and penobarbital. Okay? Drugs and most of our drugs are weak electrolytes. Completely ionized. So non electrolytes. These are compounds that dissolve in water. However, electricity ionized or charges. So they are termed as your non electrolytes, and these are your sugar, glycerine, naphthalene, and your your urea. Non are your your urea. Non electrolytes, these are substance, as mentioned, do not yield ion when dissolved in water. Example of nonelectrolytes are your sucrose, glycerine, naphthalene, and your urea. So 0.1 molar solution of nonelectrolyte, it produce an approximately the same colligative property as any of the nonelectrolytic solutions of equal concentration. Next are types of solvent. So can you please write this? K. So sorry. I'll annotate. Solvent. So the first is your prophilic. So protophilic from the word itself. Filic is loving. Proto so proton. Proton loving. So a good example proton protophilic are your basic solvent. Okay? They are proton acceptor. Okay? Example, I see acetone, etter, and their liquid ammonia. K? Next is c, protogenic. Protogenic, there are, they are also hold as your acidic solvent. So proton donor, acidic solvents are considered as protogenic. A good example, I see formic acid, acetic acid, sulfuric acid, liquid hydrogen chloride, and liquid hydrogen fluoride is a good example of protogenic. 3rd would be, see, amphiprotic. Amphiprotic, these are both acceptor and donor. A good example boat acceptor and donor are water and then alcohol. Last would be c, aprotic. So accept So a good example of that would be hydrocarbon. So aprotic. Clear? And then concentrations of your solute. So the amount of solute in the solution is given by the concentration. So a good example concentration, I see molarity, molality, normality. So concentration. So similarity or molar is of a solution is mole per liter of solution. Cmol is the molecular weight expressed in gram. Millimole is 1000 small. Similar molar molar molar l is consist of contains mole or 1 gram of molecular weight in a 1000 gram of the solution. Normal consist 1 gram equivalent weight in a liter of solution or 1 gram milliequivalent weight of your in a milliliter of your solution. So similarity. So similarity, symbol sorry. Letterm or sometimes letterc. K. Letterm or letterc is equal to the mole of my solute. So compute solute weight over molecular weight over liter of my solution. So let's have a practice problem. 5 grams of your nickel 2 chloride hexahydrate in enough water to make 250 ml solution. So calculate for the molarity. So let us take note first of the formula for molarity. So molarity, dau, is equal to mole of my solute over liter of my solution. Okay? So solute 5 grams. So too big is your solvent. So mole of my solute is computed as 5 grams or weight over the molecular weight of your nickel, 2 chloride hexahydrate. Okay. Sorry. K. So the first step is you will get the molecular weight of the, nickel cobalt 2 hydrate. Clear. K. So by PANO, molecular weight. Yeah. So molecular weight is 200 Calcirator. So molecular weight, 2 chloride hexahydrate, 237.7 grams. So I'll again, mole So c mole is equal to weight, 5 grams divided by 237.7 grams. Okay? So divide 5. So 2 decimal place 5 divided by 237.7 is equal to 0.210 or since 2 decimal place, 0.02 unit mole. K? So since compute in similarity, solute, Mole solute is 0.02 moles, okay, over liter of my solution. So 250 ml solution liter of my solution convert into liter. 0.250 liter. So unit could either be mole per liter or m or Okay. Common. Okay. Letter gametrin osmotic pressure anyway. 0.02 divided by 0.250 equals equals 0.08 molar. K? So 0.08 molar. Or mole per liter. Next. Clear. So using molarity, what is the mass of osmotic, oxalic acid? Chemical formula is, h 2c204 is required to make 250 ml of a 0.05 molar solution. So mass. So given, solutions So compute. Similarity is equal to weight in grams over molecular weight, okay, divided by liter of my solutions. Right? So simplify This is small lirity is equal to mole per liter or volume per liter. Yes. So since weight mole. So molarity times volume in liter, okay, is equal to mole. Mole expand This is weight over molecular weight. Since weight over times molecular weight. So final computation is molarity concentration times your volume in liter times, the molecular weight is equal to the weight of your solute. Okay? So concentration 0.05 molar times volume per liter. So 0.250 liter times molecular weight oxalic acid. So oxalic acid is h 2 c204. So 4 times 16, 2 times 12, 2 times 1. So 4 times 16 is 64. 2 times 12 is 24 plus 2. K? So 64 +24+2 is equal to 90. K. Times 90 is equal to the weight. K. So 0.05 times 0.250 times 90. The answer is 1.125 or, since 2 decimal place, 1.13, unit weight grams. Okay? So course developer formula and formula. Generally, mole is equal to mass times v. So v, volume in liter. So step Okay? So an ideal solution is one where the properties depend only on the concentration of the solute. K. Sometimes, you are you will be asked to make concentrated solution. So you are you are asked to make, sorry. Hi. Okay. So for example, you will be asked to make, 0 point sorry. So wait So for example, you will be asked to make, wait, 0.1 molar sodium chloride. K. So the first step is you will get the molecular weight. So the molecular weight of your sodium chloride is, again, 35.5 plus 23 is 58.5. So you will multiply that to the concentration, which is point 1 norma molar. Again, 0.1 molar. This is formularity. So point 1 times 58.5 0.1 times 58.5 is 5.85 grams. So point 1 molar sodium chloride 5.85 grams sodium chloride dissolve 1 liter a sufficient quantity sufficient quantity of water to make 1 liter solution. K. 1 liter mole is equal to mole of your solute per liter. Divide 1, the number itself 1 liter of my solution. So 0.1 molar sodium chloride 250. 1 liter. So so 5.85 grams 250. Okay? So 5.85 times 0.250 divided by 1 is 1.4625. Okay? So 1.46 grams sodium chloride dissolved 250 ml. To bag sufficient quantity of water to make 250 ml. Sufficient quantity of water mole of solution solvent sufficient quantity Next. Clear? K. Next would be molality. K. Molality or is small of my solute per 1,000 grams of solvent. So molarity liter of my solution solvent So molality or m of solution is equal to mole of my solute per kilogram of my solvent, which is, again, your 1,000 gram of solvent. Percent, weight by mass. So weight solute divided by weight solutions So wait annotate. So percent weight percent weight by weight. So weight by weight, this is percent, grams or weight in solute weight solute over weight solutions. Okay. Times 100 percentage. So on solution solute plus solvent. So 10% weight by weight. Weight by weight. 10 grams solute into 100 grams solution. Solvent 90. Solute 10 grams. Okay. So Next. Clear. Calculating the concentration. 62.1 gram or 1 mole of ethylene glycol in 250 grams of water. Calculate the molarity and percentage mass of ethylene glycol. So 1 mole. Ethylene glycol molecular weight i62 point 1. 1 mole. So mole is equal to weight weight i62.1 molecular weight 62 point 1 gram per mole then. K. 1 mole. Oh, molecule. Ethylene glycol. Water 250 grams. Molarity, this is mole of my solute, solute ethylene glycol, and mole kilogram solvent. Solvent IC water weight in kilogram water. So 1 mole divided by 250 grams or in short, 0.25 kilogram is equal to 1 divided by 1 divided by 0.25 is equal to 4 mole per kilogram or m, symbol formality. Compute. Question, percent. Percentage ethylene glycol by mass. Okay. So percent weight by weight is equal to weight in gram solute, so solute 62.1 gram. Divided by grams solution. Solute solution is weight, solute plus solvent. So solute is 62.1 gram plus 250 grams. So 62.1 plus 650 is 712.1. 62.1 divided by 7112.1, the answer is 62.1 +253112.62.1 +253112.1 +250 is equal to to 312.1. 62.1 divided by 312.1 is equal to 0.1989. 0.1989. Ma'am. Times 100. So the answer is 19.897 or 19.9 percent weight by weight. Okay. So percent, ethylene glycol. Clear? And then next slide. So again, compute. Now try this molality problem. Okay? 200 grams of, sodium chloride 5,000 ml of water. So convert 5,000 ml of water into into kilogram since liter is equal to kilogram 5 grams So molarity, molality is equal mole of my solute divided by kilograms of my solvent. Equivalence kilogram kilogram, 5 kilogram, mole sodium chloride, 25 divided by 58.5. Molecular weight sodium chloride. So 25 divided by 58.5, the answer is 0.42735. Right? Divide 5 kilo. So the correct answer would be 0.085 or 0.09 unit or mole per kilogram. Clear all my drawings. Explanation So next, I see normality. Normality gram equivalent weight of solute in a liter of my solution. Molarity normally equivalent weight. So your equivalent weight depending on the factoid. So ion neutralization possible valences positive charge ion. Oxidation redox lost or gain electron. So problem. K? So if assumed that the sample of sodium carbonate weighing 1.625 grams required 30.2 ml of as of acid and titration, what is the normality of the acid? So convert similarity. Okay. So convert molarity to normality. Normality is equal to molarity times the number of day lengths. So one normal NaCl is equivalent to 1 molar NaCl valence sodium chloride. Sodium carbonate. C 1 molar sodium chlora carbonate sodium carbonate. Again, 1 molar sodium carbonate, equivalent 2 normal sodium carbonate valence I 2 positively charged ion 2 times concentration 1 2 normal So try formula normality. So see, normality, as mentioned, is equal to gram equivalent weight per liter of my solution or one. This is milliequivalent weight over liter of my solution. So, molecular weight sodium carbonate. So sodium carbonate 3 times 16, 12, 2 times 23. So this is 3 times 16 is 48 +12plus46. So 48+ 12+46 is 101 106. Okay? Gram equivalent weight. Weight weight 1.6250 gram. Divide equivalent weight molecular weight divided by positively charged balance case sodium carbonate. So 106 divided by 2 is 53. So divide by 53 divided by liter of my solution. So invert 30.2 ml 0.03020 liter. K? So liter 1.6250 divided by 53 divided by 0.03020. The answer would be 1.015 normal. Okay? Milliequivalentweight milliequivalentweight divide 1,000 represented ml. You will end up with the same answer as 1.015 normal. K? Next. Clear. So sunode I see. 0.2800 gram of sodium bicarbonate. Nitrate with 0.9165 normal sulfuric acid. Volume produce, endpoint in a liter. K? So, actually, the liter. Okay. So normality is equal to gram equivalent weight over liter of mice solution. Okay? So normality. Okay? Volume. I see volume. So volume or liter is equal to gram equivalent weight over your normality. So gram equivalent weight. Yeah? So 0.28 divided by sodium bicarbonate, I see no solat as NaHCO 3. So 3 times 16, 12, 1, 23. Okay? So 3 times 16 is 48 plus 12 plus 1 plus 23. The answer is 84. Equivalent valence transcript 84, 84 Okay? Factor 1. Okay. No. 1. 1. Okay. In a liter of oh, an an in a normal, okay, normality. So 0.9165 normal. Okay? So point 28 divided by 84 divided by 0.9165 equals 0.003637 or 3.63 times 10 to the negative 3. So whole number Since end point liter times 1,000 so the correct answer is 3.64 3.64 liters. Okay? So, Okay. Do you see? Do you have any question? But, actually, confusion side notes course developer. Names one 1,000 volume So 0.00 3 liters. So ml ml. So ml times 1,000 3.64 ml. Okay? So next, I hope k? So so no, I see percentage, expression. So percentage expression weight by weight. So so percentage in a 100 grams of solution. See, weight by volume or volume by volume, ml of your solute in a hand solute, Melissa. Solute in a 100 ml of solution. And then, gram per volume is gram of solute in a 100 grams of solution. So when we say equivalent weight, it is a mass of 1 equivalent that is mass in a given substance, which will supply or require with 1 mole of hydrogen cation in an acid base reaction, supply or react with 1 mole of electron in a redox reaction? This is again termed as your gram equivalent weight. So equivalent weight, atomic weight, divide number of equivalents or valence. So using the equivalent weight, equivalent per mole potassium per, potassium phosphate. K? So what is the equivalent weight of this salt? So number of equivalent. Yeah. So potassium, phosphate potassium is positive 1, phosphate is negative 3. So number of equivalent positively charged ion, positive one times 3, subscription, so number of equivalent 3 equivalent per mole. Equivalent weight is molecular weight divided by the number of equivalent. So equivalent, molecular weight 312 gram per mole divided by 3 70.7 gram equivalent. So gram equivalent weight is equal to molecular weight divided by the factor or the total positively charged ion. So I would like you to answer the following. Give the formula, the molecular weight, and the fall, the equivalent weight of the following compounds. Next, problem solving. So we have 0.2 molar solutions of sodium chloride in water with a specific gravity of 1.5. Compute for how many grams of sodium chlorides present and what is the molarity of the solution. So this would be your assignment as well. So we have this aluminum sulfate. The molecular weight is 342. What is the gram equivalent weight? So, again, gram equivalent weight is molecular weight over positive recharge factor. So aluminum is under group 3 times 2 subscript sulfur, which is as sulfate, which is negative 2 3 times 2 is 6 factor number of equivalent. So equivalent gram equivalent weight I 57. K. So milliosmoles. So milliosmoles or milliosmolar value or separate ions of an electrolyte may be obtained by dividing concentration of milligrams per liter of the ions by an atomic weight. So compute milliosmole, I see osmolarity. So the symbol for osmolarity is milliosmole per liter. So this is equal to the weight in gram per liter divided by the molecular weight in gram times the number of species. Take note number of species factor So aluminum sulfate. Ionize osmole is dividing the concentration of the ion by atomic weight. Aluminum sulfate ionize aluminum Okay. Toposulfate species ions So number of species Okay? Times 1,000. So weight in gram per liter over molecular weight times 1, times, number of species times 1,000. Per liter concentration k. K. Wait. Annotate. K. Weight in grams per liter divided by the molecular weight times number species times 1,000. K? So solution containing 1%, weight by volume. Aluminum sulfate 14, 14 hydrated 14. Okay. Molecular weight 16. Complete ionization. Calculate the osmolarity of the solution. K. So gram per liter. 1% weight by volume weight by volume weight by volume is gram of my solute per 100 ml of my solution. So 1 gram in a 100 ml grams in a liter. So liter ml So 1 times 1,000 divided by 100 equals 10. So grams per liter 1 percent, so 10 gram per liter divided by molecular weight 600. Okay? Times number of species. Hydrated form. So ionize. Okay. Water. So atomic weight. Okay. Or molecular weight ionization. So aluminum sulfate complete ionizer number species aluminum sulfate. So 5 times 1,000, 10 divided by 600 600 times 5 times 1,000 equals 83.83 milliosmole per liter. So compute computation Okay? So compute. Let us try this. Small calcium chloride. So calcium chloride molecular weight molecular weight 111. So 111. So 111. 111. K. 111. Yes. 111 calcium chloride. Okay. Calcium chloride. Ca positive chlorine is negative one CaCl2. So gram per liter. So 10 grams per 100 ml ma'am? So 10 times 1,000 divided by 100. So 10 grams per I 10 100 100 grams per liter. Sorry. Okay. So 100 grams per liter. Divided by the molecular weight, 111, okay, times number of species. Calcium chlorine. So times 1,000 equals 100 divided by 111 times 3 times 1,000 is equal to what? 100 divided by 111 times 3 times 1,000 equals 111 times 3 times 1,000 is 2,000 2,000 703 milliosmol per liter. Okay. Okay. And 104, 1 140 ml. So so is 397.2. So check this would be again your another assignment. Okay? Mm-mm. So Next. Molar mole fraction. Mole fraction. Part solute solvent So mole solute a divided by solution. Solute solution. Okay. Solvent. Okay. So So the path 1. Okay. So practice problem. So 1 mole down sodium chloride. 100 grams water. Mole fraction sodium chloride. So fraction sodium chloride. So mole fraction is equal to mole sodium chloride divided by solution, which means sodium chloride plus water. Okay? So sodium chloride, 0.1. K. So water. K. Using 100 grams too big divided by 18 grams per mole. 5.56, mole water. So divide 5.56 +0.1. So got I 0.018 mole. K? Mole fraction water 5.56 divide 5.56 +0.1. So 0.982 add 1 fraction 1. K? So to end this, this last part would be, again, your assignment. Understand this. And for another reading, assignment, you can check YouTube discussion for molarity, normality, and molarity. Molarity formality. So molarity, molecular weight formality form formula weight. So Okay. Thank you so much, and god bless