Yahoo Answers is shutting down on May 4th, 2021 (Eastern Time) and beginning April 20th, 2021 (Eastern Time) the Yahoo Answers website will be in read-only mode. There will be no changes to other Yahoo properties or services, or your Yahoo account. You can find more information about the Yahoo Answers shutdown and how to download your data on this help page.

Trending News

Promoted
Janice P
Janice P asked in Science & MathematicsChemistry · 7 years ago

AP Chemistry mass percent problem?

Update:

A pharmacist prepares an antiulcer medicine by mixing 286g Na2CO3 with water,adding 150g C2H5NO2, and stirring continuously at 40°C until a firm mass results.The pharmacist heats the mass gently until all the water has been driven away.No other chemical changes occur in this step.Compute the mass percentage of carbon in the result­ing white crystalline medicine.

So basically, find the mass percentage of carbon of 286 g Na2CO3 and 150 g C2H5NO2. My main issue is how to find the g/mol ofthe total

2 Answers

Relevance
  • Old Science Guy
    Lv 7
    7 years ago
    Favorite Answer

    from the problem statement

    I think we may assume that starting amounts

    are still present in the final mixture

    so we need to find the mass of carbon and compare to total mass

    286 g Na2CO3 * 12.0 g C / 105.99 g Na2CO3 =32.38 g C

    150 g C2H5NO2 * 24.0 g C / 75.07 g C2H5NO2 = 47.96 g C

    so

    X/100% = (32.38 + 47.96) / (286 + 150) = 0.184

    X = 18.4% C

    If someone gives you a good answer,

    please consider giving a best answer.

    This is the only reward we get.

  • Anonymous
    7 years ago

    420%

Still have questions? Get your answers by asking now.