Chapter 6: Solutions and pH

The Fraser River Estuary: where the Fraser River and the Pacific Ocean meet!

Chapter 6: Solutions and pH The river is a complex mixture with many BIG and small particles… Ex. dissolved substances (particles that you can’t see) like fertilizers, chemicals from industry waste, & run-off from cities.

Chapter 6: Solutions and pH Chapter 6 Goals: How concentrated solutions and dilute solutions are different How concentrated solutions and dilute solutions are different How to separate the parts of a solution How to separate the parts of a solution How to identify acids and bases How to identify acids and bases

Solutes and Solvents Solubility : the ability of something (solute) to dissolve in a liquid (solvent) If it’s SOLUBLE it can dissolve. If it’s SOLUBLE it can dissolve. If it’s INSOLUBLE it cannot dissolve. If it’s INSOLUBLE it cannot dissolve. Ex. Sugar in water Ex. Sugar in water Ex. Gold in water Ex. Gold in water

the substance that dissolves Solute – the substance that dissolves Ex. Kool-Aid crystals, sugar, salt – the substance in which the solute dissolves. Solvent – the substance in which the solute dissolves. Ex. Water Solution - a solution is made when two or more substances combine to form a mixture that looks the same throughout Solutes and Solvents

Water is the universal SOLVENT

Ex. Vinegar Ethanoic acid in water Ex. Lemon-lime soda Carbon dioxide gas, sugar, and flavour Carbon dioxide gas, sugar, and flavour Others? Solutions

particles are always in motion Remember this?? Particle Model of Matter

Bit by bit the water works its way into the solute, making more room for more water to move around it, continuing to break it apart. Sugar dissolved in water

Chlorophyll in water is NOT soluble (Chlorophyll in alcohol IS soluble) Others? What’s INSOLUBLE? - - it depends on the solvent

Dilute Solution: Has a small amount of dissolved solute for a certain amount of solvent. Ex. When I make orange juice from concentrate my son refuses to drink it. Concentrated solution: Has a large amount of solute compared to the solvent. Has a large amount of solute compared to the solvent. Ex. When my son makes orange juice, it’s too sweet! Dilution and Concentration How do you make it more (or less) sweet?

Saturated Solution: You can no longer add solute to your solution! It will no longer dissolve. Ex. 37.5g of salt is the maximum amount that can be dissolved in 100mL of water. It has reached it’s SATURATION POINT. Unsaturated Solution: You can still add solute to your solution and it will dissolve. You can still add solute to your solution and it will dissolve. Dissolving What’s a SUPERSATURATION?

The mass of solute that can dissolve in a certain volume or mass of solvent, at certain temperature. Ex. Solubility of salt at 0 o C is 37.5g/100g Look at Table 6.1 on pg. 167 Compare the masses of different sokutes that dissolve in water at 0 o C Is the hummingbird feeder solution saturated or unsaturated? Solubility

How fast something will dissolve. What affects the rate of dissolving? Stirring, temperature… Rate of Dissolving

particles are always in motion Particles at a higher temperature are moving faster than particles at a lower temperature. Particles at a higher temperature are moving faster than particles at a lower temperature. Remember this?? Particle Model of Matter Particle Model of Matter used to describe the different features of matter