HUMA 205 Lecture Notes - Lecture 2: Hydrophile, Osmosis, Chemical Polarity
A. State the standard units of measurements for length, mass and
volume and understand how to convert from one unit to another:
- Metric system or SI(interna>onal system is a decimal system
based on 10 which is the main one used
- Length : uses unit of metre (m) and is converted from inches: 1
metre = 39.4 inches and 1 metre = 3 feet
- Volume: mass measurement of an object
- Quan>ty of material it contains
- Measured on balance
- Unit of gram (g) in metric system
- Unit of kilogram (kg) in SI system
- Temperature: measurement of a substance
- Measured on Celsuis in metric system
- SI system uses the Kelvin scale which means 1K is equal to -273
degrees celsuis
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- Pre+xes in measurement: are a way of represen5ng very large
and small numbers by using a log 10 nota5on
- Micro: means 10-6 or 1 millionth or 1/1000000
- Milli: means 10-3 or 1 thousandth or 1/1000
- Kilo: means 103 or 100 5mes or 1000x
B. Describe solutes, solvents and solu5ons:
- Solu5on: mixtures all around us
- If a mixture is uniform throughout it is called a homogenous
mixture which is a solu5on
- Blood plasma is a solu5on as well as intracellular and
extracellular Juids
- When a solu5on consists of a solid or gas dissolved in a liquid, the
solid or gas is called the solute while the liquid is called the
solvent
- If liquid is dissolved in liquid, the one present in greater amount
is called the solvent
- Characteris5cs of solu5ons:
- Distribu5on of par5cles is uniform
- Components do not separate on standing
- Can’t be separated by +ltra5on
- Possible to make solu5ons of many di;erent composi5ons given
any solute or solu5on
- Almost always transparent
- Usually composed of small molecules or ions
C. Describe what is meant by concentra5on of a solu5on and how it is
de+ned:
- Amount of solute dissolved in a given quan5ty of solvent
- Commonly used methods: percent concentra5on (m/v%),
molarity (M or mol/L or mol.L-1), parts per million (ppm)
- Solubility: maximum amount of the solid that will dissolve in a
given amount of liquid at a given temperature
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- A physical constant
- Each solid has a di;erent solubility in each liquid
D. De+ne a mole and a Molar solu<on:
- Molarity: the number of moles of solute dissolved in 1 litre of
solu<on
- Number of moles is unknown:
-
- 3 moles glucose in water and made up to 6L of solu<on: M=
3/6 = 0.5 M
- Mole: name for a speci+c number of things
- Equal to 602 hexillion
- Scien<+c nota<on: 6.02 x 1023
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Document Summary
State the standard units of measurements for length, mass and volume and understand how to convert from one unit to another: Metric system or si(internaonal system is a decimal system. : uses unit of metre (m) and is converted from inches: 1 based on 10 which is the main one used. Length metre = 39. 4 inches and 1 metre = 3 feet mass measurement of an object. Unit of gram (g) in metric system. Unit of kilogram (kg) in si system. Si system uses the kelvin scale which means 1k is equal to -273 degrees celsuis. Pre+xes in measurement: are a way of represenng very large and small numbers by using a log 10 notaon. Micro: means 10-6 or 1 millionth or 1/1000000. Milli: means 10-3 or 1 thousandth or 1/1000. Kilo: means 103 or 100 mes or 1000x: describe solutes, solvents and soluons: mixtures all around us.
