Chem help?

posted by .

In an experiment 5.57 +/- 0.02 grams of water chemically decomposes into the products hydrogen gas and oxygen gas. The measured mass of oxygen gas produced in the reaction is 4.9320 +/- 0.0001 grams. The hydrogen gas occupies a volume of 6902 mL. Report the density of the hydrogen gas produced to the correct number of significant digits (Do not perform any calculation involving the estimates of uncertainties in the measurements.)

My answer is 9.24 *10^-5....Is it the right num of sig figs?

  • Chem help? -

    I also get 9.24 x 10^-5 but I don't think that is the correct number of s.f.
    You subtracted 5.57 - 4.9320 = 0.638 but that must be rounded to 0.64 because in addition or subtraction we can't have more places after the decimal than the least precise. Then 0.64/6902 = 9.27 x 10^-5 which would round to 9.3 x 10^-5 g/mL. If you kept the 0.638/6902 = 9.24 x 10^-5 which rounds to 9.2 x 10^-5 g/mL. I have always kept the less precise number in my calculator and do it all at once; i.e., (5.57-4.9320)/6902 =?? instead of subtracting, rounding, then dividing, then rounding again. Therefore, I would go with 9.2 x 10^-5 g/mL instead of the 9.3 but you need to follow the instructions of your prof. That is, do you subtract, round, then divide, and round again or do you do all of the calculations at one time and round only once. I ALWAYS carry one more place in intermediate calculations, then round only one time at the end. My experience is that if I round too many times, I get rounding errors. Again, however, do what you prof has taught you. I would like to know what is being taught these days, just for my own information.

  • Chem help? -

    9.24 *10^-5

Respond to this Question

First Name
School Subject
Your Answer

Similar Questions

  1. Science

    A sample of water decomposes to make 4g of hydrogen gas and 32g of oxygen gas. What mass of water decomposed?
  2. CHEM!!

    In an experiment 5.57 +/- 0.02 grams of water chemically decomposes into the products hydrogen gas and oxygen gas. The measured mass of oxygen gas produced in the reaction is 4.9320 +/- 0.0001 grams. The hydrogen gas occupies a volume …
  3. Chem

    In an experiment 16.81 +/- 0.02 grams of hydrogen peroxide chemically decomposes into the products water and oxygen gas. The measured mass of oxygen gas produced in the reaction is 8.854 +/- 0.003 grams. Report the mass of water produced …
  4. Chem

    In an experiment 16.81 +/- 0.02 grams of hydrogen peroxide chemically decomposes into the products water and oxygen gas. The measured mass of oxygen gas produced in the reaction is 8.854 +/- 0.003 grams. Report the mass of water produced …
  5. chemistry

    Calculate the mass (in grams) of water vapor produced when 56.0 grams of pure hydrogen gas burn in the air. Given the information from that, calculate the mass of oxygen gas that would be needed to burn 100 grams of hydrogen gas.
  6. chemistry

    Calculate the mass (in grams) of water vapor produced when 56.0 grams of pure hydrogen gas burn in the air. Given the information from that, calculate the mass of oxygen gas that would be needed to burn 100 grams of hydrogen gas.
  7. chemistry

    Write word equations for the following chemical reactions. a. Pure copper can be produced by heating copper(II) sulfide in the presence of diatomic oxygen from the air. Sulfur dioxide gas is also produced in this reaction. b. Water …
  8. Chemistry

    A certain compound contains carbon, hydrogen , and oxygen. When 1.00 grams of this compound are burned in oxygen gas 1.47 grams of CO2 and 0.600 grams of water are formed. When 2.75 grams of the compound are dissolved in 10.0 grams …
  9. Chemistry

    1. Hydrogen gas combines with oxygen gas to yield water. if 15 g O2 is present in the reaction, compute how much water will be produced. 2. Ten (10)grams methane gas combines with oxygen gas to form water and carbon dioxide. How much …
  10. Chemistry

    when electricity is passed through water, the water decomposes into hydrogen gas and oxygen gas. when 10.00 kg of water were decomposed this way, 5788 l of oxygen gas were produced at 25 degrees celsius and 1 atm pressure. what is …

More Similar Questions