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SOLUBILITY. A measure of how much a gas, liquid, or solid becomes dissolved in a liquid. MTBE: Methyl Tertiary Butyl Ether. A liquid that is very soluble in gasoline and used to get more complete combustion of gasoline.
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SOLUBILITY A measure of how much a gas, liquid, or solid becomes dissolved in a liquid.
MTBE: Methyl Tertiary Butyl Ether A liquid that is very soluble in gasoline and used to get more complete combustion of gasoline. Unfortunately, also soluble in water. 42 g per liter. Can be tasted at 0.0001 g / liter Over 20,000 of these storage tanks are estimated to be leaking in Virginia
Salt (NaCl) is very soluble in water. 350 g/liter. However, if water evaporates, there will be too much salt for the water to hold in solution. The salt begins to form crystals. A lake near Death Valley is supersaturated with salt causing the salt to crystallize out.
Once a year the company who owns the lakes lets visitors into the area to collect salt crystals.
Applications of Solubility Knowledge Cleaning Separation (purifying) Detection & Identification
Like dissolves like • To dissolve grease, use something that is also greasy or oily.
Water: the Universal Solvent One side of water is negatively charged because the oxygen atom keeps the shared electrons longer than the hydrogen atoms. As a result theoxygen side is negatively chargedand the hydrogen side of water is positively charged. O
O O O O O Water: the Universal Solvent Like a magnet that pulls on things that are magnetic, water pulls on things that are electrically charged. Magnets have north & south poles, water has positive and negative poles and thus called a polar solvent. Since unlike charges attract, the negative end of water will be attracted to the positive sodium ion. The positive end of water will be attracted to the negative chloride ion. Since water is always in motion, it will pull on the ionic compound and move the ions away from each other. This dissolves the ionic compound. Cl- Na+
O O O O O Wax does not repel water We’ve heard that wax or oils repel water. But that isn’t true. Water is so attracted to other water molecules that anything between them is squeezed out of the way. Oildroplet
Water is always trying to pull itself into a tight ball as long as there is nothing nearby that has a charge on it. Therefore, this surface is not repelling water; it’s simply not attracting it and keeping water from doing what it does naturally.
We see the same effect on waxy leaves. Water pulls on itself so much that it forms a “skin.” It’s called surface tension.
We are lucky that water has this strong attraction force otherwise we’d never see raindrops. The water would just breakup into a mist as it fell. Very few liquids would remain as drops if they fell from a large height.
O O O O O O SO4- SO4- SO4- SO4- SO4- SO4- Soaps & Detergents Soaps and detergents are chains that have one end that is like oil and has no charge and the other end is charged. Oildroplet
O CH3-C-CH3 Acetone • Solvent for fats, oils, waxes, resins, rubber, plastics, varnishes, nail polish remover, solvent for adhesives & printing inks, • Antiseptic solutions--to facilitate penetration • The evaporation rate of acetone makes it quite useful for cleaning and drying. It “dissolves” water so you can wash away water allowing items to dry faster.
Concentration of solutions Approximate Quantitative
Approximate Descriptions of Concentration Unsaturated Dilute Concentrated Saturated Supersaturated Alum
This reference book indicates the solubility of many inorganic and organic compounds.
Approximate Guess what these abbreviations stand for. Click on them for answer. water alcohol ether acetone benzene Next Slide
ether very soluble in Ethanol slightly soluble in benzene soluble in water chloroform Try to guess what these abbreviations mean and then click on them for answers. Chemical Abstracts Service
Mass Percent (w/w) solid mixtures/ solids in solvents Mass/Volume (w/v) mg/mL, g/Liter Medical solutions g/100mL or g/100cc Mass/Volume Percent (w/v) Volume Percent (v/v) Liquid in liquid, liquors Parts per million (ppm)mg/liter (if water) wt or vol Trace amounts in water or air Molarity (M)(mol/liter) Chemistry reagents Quantitative Measurement of Concentrations
Mass/Volume (w/v) These can be easily turned into Mass/Volume Percent (w/v) Na3P Saturated solutions
Mass/Volume Percent (w/v) 0.14 grams per 100 cc. Many products list the concentration of their ingredients. Fluoride is the active ingredient. Na2PO3F Apparently F replaces one of the oxygens, and since F has 7 electrons then the “phosphate” is -2 instead of -3. Na2PO3F Mol Wt= 144. 1.06% if stated as wt/vol of Na2PO3F
0.243 grams NaF per 100 cc. 0.15 grams Fluoride ion per 100 cc.
Insecticides are often dissolved in solvents. Their concentrations are usually given as sample weight divided by solvent weight converted to percent.
For every 100 grams, how much of it is Diazinon? Mass Percent (w/w)
Grams100 mL Mass/Volume Percent (w/v) 100100 = g 100 mL 5mg1mL 0.5 .001milli Two ways of showing concentration are given. Let’s turn 5mg per mL into 0.5% to see they are the same.
Mass/Volume Percent (w/v) 1% = 1g/100mL 0.2%= 0.2g/100mL 0.2%=0.2g/100mL 0.2g 15mL = .03 grams 100mL To calculate the grams of glycerin in this bottle use dimensional analysis.
Mass/Volume Percent (w/v) 5 g 100mL 50 g 1000 mL = 0.1 0.1 This lists the ingredients of Dextrose 5%. It says 50 grams in 1,000 mL of water. The dimensional analysis above shows how 50g per 1000mL can be converted to 5% (w/v)
39g = .11 g355mL 1 mL .11 g 100 = 11g = 11% (w/v) 1 mL 100 100mL Calculate Mass/Volume Percent (w/v) Find grams per mL (divide 39g by 355mL) Multiply by 100 to get grams per 100mL Calculate the percent (w/v) of sugar.
Ionic Breeze® complies with U.S. requirements for low ozone emission (less than 50 parts per billion) O.S.H.A. 24 hour exposure limit, 0.05 PPM, {Parts Per Million} The product lists 50 parts per billion (ppb) concentration of ozone. OSHA, however, lists the level as 0.05 ppm. Let’s convert the ppm to ppb to better compare these values. After multiplying by 1000 we find the 0.05 ppm is the same as 50 ppb. 0.05 1000 = 50 1,000,000 1000 1,000,000,000
Quantitative Measurement of Concentrations Mass Percent (w/w) solid mixtures/ solids in solvents Mass/Volume (w/v) mg/mL, g/Liter Medical solutions g/100mL or g/100cc Mass/Volume Percent (w/v) Volume Percent (v/v) Liquid in liquid, liquors Parts per million (ppm)mg/liter (if water) wt or vol Trace amounts in water or air Molarity (M)(mol/liter) Chemistry reagents
Convert gramsto moles Convert moles to grams You want to neutralize 360 grams NaOH How many grams of HCl is needed? Reactants Products • Weight • Weight Chemical reaction NaOH(aq)+ HCl(aq) NaCl(aq) +HOH(l) 9 360 g NaOH = moles NaOH mole g 1 40
Convert gramsto moles Convert moles to grams You want to neutralize 360 grams NaOH How many grams of HCl is needed? Reactants Products • Weight • Weight Chemical reaction 9 moles 9 moles NaOH(aq)+ HCl(aq) NaCl(aq) +HOH(l) 328.5 9 moles HCl = grams HCl g mole 36.5 1
Products Reactants Molarity = M • Weight • Volume • Concentration • Weight • Volume • Concentration 1 moleLiter 1 M = If you had half a liter of 1M NaOH, how much 1M HCl is needed to neutralized it. Convert volume& Conc.to moles For NaOH, 40 grams in one liter makes 1 M. Convert moles to Volume Chemical reaction NaOH(aq)+ HCl(aq) NaCl(aq) +HOH(l) 1 M 1 M
Ingredients: Aspirin 325 mg, sodium bicarbonate 1700 mg, citric acid 1000 mg. • Reactions go faster if the reactants are well mixed. Dissolving them first in water and then mixing them makes the reaction go faster.
Concentration based on Moles per Liter • This bottle of Sodium Phosphate lists the concentration as 0.1 M. How many moles of sodium phosphate are there in one liter of this solution? • How many moles of sodium phosphate in 3 liters? • How many moles in 0.1 liters?
We’ve used silver nitrate to test for chloride ion (Cl-) in a few lab experiments. • Ag+ + Cl- AgCl(s) • Silver nitrate dissolved in water is a convenient way to add a small amount of silver nitrate to something else to see if a reaction occurs with either the silver or the nitrate. • If this bottle is 250 mL, how many moles of silver nitrate does it contain? 250mL x 0.001 milli =0.250 L 0.25L x 0.2 moles 1 Liter = 0.05 moles
We’ve used silver nitrate to test for chloride ion (Cl-) in a few lab experiments. • Ag+ + Cl- AgCl(s) A salt solution is 0.2 M NaCl. How much of this salt solution is needed to precipitate all of the Ag+ from this one liter bottle? What if the NaCl solution was 0.4 molar? How much would be needed?
Let’s say the left bottle is 4 liters. How many moles of sodium arsenate are in a full bottle? How much sodium arsenate would you weigh out to make up 4 liters of this 0.1M solution?