ATAR Notes: Forum

VCE Stuff => VCE Science => VCE Mathematics/Science/Technology => VCE Subjects + Help => VCE Chemistry => Topic started by: The Detective on April 10, 2011, 10:28:24 am

Title: Conversion question
Post by: The Detective on April 10, 2011, 10:28:24 am

How to convert 120 micrograms/ml to ppb? The answer is 120000ppb

Thanks  :)

Title: Re: Conversion question
Post by: vea on April 10, 2011, 10:38:41 am

Hey guys, kinda off topic but what "billion" do we use in Australia?

In the UK 1,000,000,000,000 is a billion while in the US 1,000,000,000 is a billion.
I have been meaning to find this out for years...

Thanks and sorry for hijacking your thread detective (though it kinda is relevant) :P

Title: Re: Conversion question
Post by: jasoN- on April 10, 2011, 10:46:41 am

1,000,000,000 is 1 billion
1,000,000,000,000 is 1 trillion

Anyways
1 μg/kg = 1 ppb       (μg = microgram)
so 1 μg/L = 1ppb
    0.001 μg/mL = 1ppb

ratios:
120 μg     = x ppb
0.001 μg   = 1 ppb
x = 120/0.001 = 120000 ppb

Title: Re: Conversion question
Post by: VivaTequila on April 12, 2011, 12:55:24 am

Sorry to go offtopic, but how does %w/w work?

If you say you have 70g/100g of NaCl in a solid, then is that 70g of NaCl to 100g of (non NaCl) solid or 70g of NaCl in 100g of solid (meaning 30g of non NaCl solid)?

Title: Re: Conversion question
Post by: Greatness on April 12, 2011, 11:14:11 am

%w/w means grams per 100 grams.
If yuo have 5% of Fe in a sample then there is 5g of that within 100g (so there is 95g of other substances). Im think thats what it means.

Title: Re: Conversion question
Post by: schnappy on April 15, 2011, 02:53:26 am

Quote from: VivaTequila on April 12, 2011, 12:55:24 am

Sorry to go offtopic, but how does %w/w work?

If you say you have 70g/100g of NaCl in a solid, then is that 70g of NaCl to 100g of (non NaCl) solid or 70g of NaCl in 100g of solid (meaning 30g of non NaCl solid)?

In every 100g of sample, there is 70g NaCl.

Title: Re: Conversion question
Post by: VivaTequila on April 25, 2011, 04:50:58 pm

Thanks for confirming schnappy +1

Assuming same for %v/v, and %w/v?

Title: Re: Conversion question
Post by: cohen on April 25, 2011, 05:00:30 pm

http://uppit.com/0uvbw5p7e747/Ways_of_expressing_concentration.docx

Here's a sheet I made, It contains the different types of concentrations, and how to convert them (I didn't write anything relating to PPB, but i'll update it when i can be bothered :P )