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Converting grams into Milligrams per 100 grams

  1. Jun 9, 2017 #1
    1. The problem statement, all variables and given/known data
    What is the ratio of the amount of Vitamin C in 500 grams of orange to the amount of Vitamin C in 500 grams of orange juice?

    There is a graph associated with this question which is attached.
    bar grams to mg per 100 grams p366q1andq2.jpg
    I cant find out the amount of Vitamin C in 500 grams because the data is given in terms of Milligrams per 100 grams and they are asking data in only grams. I don’t know how to convert 500 grams to milligrams per 100 grams.
    2. Relevant equations
    1000 mg = 1 gram


    3. The attempt at a solution
    I get the data so i cant solve it.
    Some body please guide me
    Zulfi.
     

    Attached Files:

  2. jcsd
  3. Jun 9, 2017 #2
    What's the problem? They tell you how many mg in 100g, so how many mg are there in 500g?
    You don't even need to work that out. The ratio of the amount in 500g orange to the amount in 500g orange juice is the same as the ratio of the amount in 100g orange to the amount in 100g orange juice, or the amount in 467,238g orange to 467,238g orange juice, or...
    So you only need to compare the lengths of the bars on the graph.
     
  4. Jun 9, 2017 #3

    scottdave

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    Gold Member

    I think the fact that it is a mass per mass "unit" is confusing you. If it said something like "my car can drive 1000 miles in 100 gallons, how many miles can I drive on 500 gallons?" could you solve it then? You can take [(1000 mile) /(100 gal)]*(500 gal) and get 5000 miles, as the gallons 'cancel'. See if you can do something similar with the units given in your problem.
     
  5. Jun 10, 2017 #4
    Hi,
    Thanks. I cant figure it out. I got following:
    1000 mg = 1gm
    or 1gm = 1000 mg
    500 gm = 500 * 1000 mg
    500 * 1000 mg/100 gm = 500 * 1000 mg / 100 * 1000 mg
    = 5 mg
    Is this correct?
    How can i check this value in the graph for Vitamin C in orange and for Vitamin C in Orange juice?

    Some body please guide me.

    Zulfi.
     
  6. Jun 10, 2017 #5

    CWatters

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    If you were asked about the ratio of wheels on a 16 wheel lorry compared to a 4 wheel car you would calculate it as follows...

    16 wheels : 4 wheels
    then divide both sides by "wheels" giving you..
    16:4
    then divide both sides by 4 giving you
    4:1
    The point is that both quantities are in the same units (wheels) so the units cancel.

    If I asked about the ratio of wheels on TEN 16 wheel lorries compared to TEN 4 wheel cars you would calculate it as follows...

    10*16 wheels : 10*4 wheels
    then you can divide by 10, 4 and "wheels" giving you
    4:1

    The point is that the TEN is the same on both sides so it also cancels.

    Back to your question...

    The first chart has data for orange and orange juice in the same units (mg per 100g).

    The question asks for
    again units are the same.

    So no need to mess around with any conversions as the units will all cancel.
     
  7. Jun 10, 2017 #6

    CWatters

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    So using the chart...

    How much Vit C is there in Orange (in milligrams per 100 grams)
    How much Vit C is there in Orange Juice (in milligrams per 100 grams)
     
  8. Jun 11, 2017 #7
    Hi,
    Vitamin C in Orange = 70mg/100 g
    Hi,
    Thanks all for your guidance. I am able to solve one part of the question.
    Vitamin C in Orange Juice = 40 mg/100g

    Ratio= 70/40= 7:4


    Thanks for helping me in solving this question. There is another question related to this graph

    Q. How many grams of tomato would you have to eat to be certain of getting more vitamin C than you would get by eating 100 g of raw broccoli?

    According to 2nd graph, the bar for raw broccoli goes from 76 – 166= 90 mg

    The bar for tomato goes from 10-25 = 15 mg

    But tomato reading is given in the upper graph also, so which reading should I consider?

    Also how would I know the vitamin C associated with 100g of raw broccoli?


    Some body please guide me.
    Zulfi.
     
  9. Jun 11, 2017 #8

    CWatters

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    What it's saying is that raw broccoli might contain anywhere between 76 and 166 mg of Vit C per 100g of broccoli.

    The question asks..

    Hint: The broccoli you buy could turn out to be at the upper end of the range and the tomato could be at the lower end of the range.
     
  10. Jun 12, 2017 #9
    Hi,
    Thanks for your help. I am able to understand this. Good hint:
    100 g of tomato = 10 mg of vitamin C
    or 10 mg of vitamin C = 100 g of tomato
    1 mg of vitamin C = 100/10 g of tomato
    165 mg of vitamin C = 100/10 * 165
    =1650

    Zulfi.
     
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