# Biomed techniques lecture 1

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• Created by: Amh
• Created on: 11-01-16 09:26
What is the prefix of the subunit 10 ^-3
milli m
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What is the prefix of the subunit 10 ^-6
micro u
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What is the prefix of the subunit 10 ^-9
nano n
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What is the prefix of the subunit 10 ^-12
pico p
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how many digits should be used?
depends on accuracy of method, accuraacy of least accurate measurement,
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What are the key rules in determining rounding of last digit and amount of digits
When digit next to last one to be retained is less than 5, last digit left unchanged If digit next to last is greater than 5, last digit is increased by 1 If digit is 5 then last digit to be reported is changed to nearest even number
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what are exponents?
The exponent of a number says how many times to use the number in a multiplication. can be positive or negative.
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what are solutions
Mixtures of substances
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What is a solute
Substances being dissolved
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What is a solvent
the substance into which a solute is being dissolved.
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How do we measure solution concentration
1. weight per unit weight, 2 weight mass per unit volume, 3 volume/unit volume, 4. percent %, 5. morality M, 6. normality N
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What is weight mass per unit volume
Amount of solute (substance that goes into solution) per volume of solution
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When is weight mass per unit volume used
When a solid chemical is diluted in a liquid
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What is w/v expressed as?
Gram per litre
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if we Want solution with concentration of 10mg/mL and require 100ml of this solution how would we obtain this (c1v1c2v2)
Well it would mean that 10mg/1mL is the equivalent to xmg over 100ml. So to work this out you do (10mg x 100ml) divided by 1ml. This gives us 1000mg
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How do you work out solution concentration, volume/unit volume
It is liquid chemical diluted with another liquid v/v, It is expressed as milli/milli, or milli/litre
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How can you express 10ml alcohol diluted to 100ml
10ml/100ml, or 100ml/L``
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what would we do if we : Require solution with concentration of 0.5ml/ml And need to prepare 1L
this means there is 0.5ml in 1ml and this is equivalent to x/100ml. So (0.5ml x 1000ml) divided by 1ml. this equals 500ml
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sHow do we work out percent solution concentraion
It is parts per 100 parts. either grams per 100ml g/100ml this is weigh per unit volume w/v% or a solution of millimeter per 100ml ml/100ml`volume/volume v/v%
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How would you express the concentration of: 10g NaCL dissolved in 100ml distilled water
10% w/v%
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in 10g of NaOH diluted in 200ml what is the concentration in percent (w/v)
There are 10 grams in 200, put this in a proportion equation. Remember %. so 10/20 is equal to ?/100. (think about ratios) so (10g x 100ml) / 100ml = x = 5% 5g/100ml
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what is molarity
Molarity is a unit of concentration that specifically relates the number of moles of a solute per liter of solution. To get the molarity, you divide the moles of solute by the litres of solution.
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what are the units of molarity
mol/litre
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How do you calculate molarity
To calculate the molarity of a solution, you need to know the number of moles of solute and the total volume of the solution. 1. Calculate the number of moles of solute present. 2.Calculate the number of litres of solution present. Divide 1/2/
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## Other cards in this set

### Card 2

#### Front

What is the prefix of the subunit 10 ^-6

micro u

### Card 3

#### Front

What is the prefix of the subunit 10 ^-9

### Card 4

#### Front

What is the prefix of the subunit 10 ^-12

### Card 5

#### Front

how many digits should be used?