percent

  1. J

    What is the weight percent in Ti(CO3)2

    I know correct answer is 14.3% and the molar mass is 167.88. But how do you get that. Please help.
  2. S

    Synthesis of Lidocaine percent yield question

    Calculate the overall percent yield of the synthesis to produce crude lidocaine. My total weight of crude lidocaine is 0.627g The limiting reagent in this reaction is diethylamine I believe. I used 7.5 mL of diethylamine (MW=73.1g/mol ; density= .71g/ml) 7.5mL*(.71g/mL)=...
  3. A

    Percent mass sugar in water

    Hi, If I put 2.00g of sugar in 50.0mL of water, what is my percent mass sugar? Is it just 4.00%, or do I need to do some calculations to the water data. Thanks so much in advance.
  4. C

    Weight percent estimate

    Can anyone walk through the steps of figuring out weight percent of an element ....I added 25g of BaF2 to water then vacuum filtered with paper but assume some Barium was lost through the filter paper...I submit for ICP analysis a small sample of the solution leftover and get back the result of...
  5. C

    Percent Composition of a Mixture?

    Hello there i'm kinda stuck on a question studying for an exam, i was wondering if anyone would be able to help me. The question is as follows: "Consider a mix of 2 solids BaCl2.2H20 + KCl with a total mass of 1.783g . After heating for 1 hour at 160 degree C , to remove all water and...
  6. brandonz

    Percent yield?

    This is the question.. If 4.0g of H2 are made to react with excess CO, how many grams of CH3OH can theoretically be produced according to the following equation? CO + 2H2 -> CH3OH Our teacher taught this to us today and we have a quiz on it tomorrow but I don't get it at all.. How do I start?
  7. S

    Finding the percent concentration of hydrogen peroxide in a consumer product?

    We were given a lab last week in Chemistry class, the problem was to find the percent concentration of hydrogen peroxide in a consumer product. A titration happened between acidic hydrogen peroxide solution and KMnO4. Previously I calculated the KMnO4's molarity and placed it in the equation...
  8. F

    Percent Present Homework Questtion

    I've been stuck on this question and can't seem to figure out the right answer. Question: Heavy water has the formula D2O, and semi-deuterated water has the formula DHO, where D stands for deuterium. Using the data from the table, estimate the percentages of D2O and DHO present in natural...
  9. B

    Calculate the percent Lithium cabonate by mass in the carbonate solution?

    A quantity of 25.0 mL of 6.0 M HCL solution is added to a 11.50g sample of an aqueous solution of lithium cabonate. The carbon dioxide gas that is generated is collected over water at 20.0 celsius and an atmospheric pressure of 725 torr. When the gas levels are equalized, the volume of the gas...
  10. S

    Determine the Percent Acetic Acid in Vinegar Sample

    :confused: Determine the percent acetic acid in the vinegar sample. (CH3COOH) -0.69 average molarity of vinegar solution -density of 0.2g/mL for the acid solution 10.0 M vinegar for titration 0.25 M NaOH solution Using a buret for titration: Volume of NaOH used : 14.6 NaOH(aq) + CH3COOH(aq)...
  11. M

    Percent Error in pH, [H+]

    Please help! I performed a pH test on 10 mL of 0.5 M HCl in lab last week. The theoretical pH was 0.3 based on [H+] of 0.5 M. The experimental pH turned out to be 0.68 (tested with a pH probe), and the experimental [H+] I calculated from pH is 0.2 M. I have 2 questions: 1. Is it correct that...
  12. E

    Stoichiometry help needed asap!

    52.8kg of sand is reacted w/ 25.8kg of C to produce 22.4kg of pure silicon. Determine the limiting reactant,theoretical yield, and percent yield for this process. I'm not necessarily asking for the answer here, just help as far as setting up the reaction map , it'll be greatly appreciated...
  13. S

    Percent yield, and mass of excess reactant. Help.

    Ok so the question goes: 15.825 g of nickel (iii) oxide and 4.734 g aluminum metal are heated to produce nickel metal and 2.85 g aluminum oxide. What percent yield of aluminum oxide? What is the mass of the excess reactant that remains unreacted so far i got the chemical formula which i...
  14. D

    percent yield

    question on chemistry test C6H12O6 yields C2H5OH + CO2 you have 100g of the sugar which yields 50ml of ethanol. density of ethanol is stated to be .789g/ml. what is the percent yield. i calculated it to be about 78%. ans is 34% my calculation gram molar wt of sugar is 180, ethanol is...