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 to the correct number of significant digits (Do not perform any calculation involving the estimates of uncertainties in the measurements.)
Is the answer 7.96 grams?? Is it the correct num of sig figs??
well you have more 00.00 sig figs than 3 so i would put it as 4 sig figs not 3
1. 7.95 g
2. 7.956 g
3. 7.96 g
4. 7.960 g
5. 8.0 g
6. 8.00
7. none of the above
Which is more the right choice....It can't be 7,6,5 for sure....But I thought it was 3. It's not 2.
Answered below with an explanation.
Use the equation below to determine how many grams of water (H2O) will be produced if 32.0 g of nitrous oxide (N20) are also produced in the reaction?
To determine the mass of water produced in the chemical reaction, we need to subtract the mass of the oxygen gas from the initial mass of hydrogen peroxide.
Given:
Mass of hydrogen peroxide = 16.81 +/- 0.02 grams
Mass of oxygen gas produced = 8.854 +/- 0.003 grams
To subtract the two values, we need to consider the uncertainties. When subtracting or adding quantities with uncertainties, we take the sum or difference of the central values and add the absolute uncertainties.
The central value for the mass of water produced = (16.81 - 8.854) grams = 7.956 grams
Now, let's consider the uncertainties:
Absolute uncertainty in the mass of hydrogen peroxide = 0.02 grams
Absolute uncertainty in the mass of oxygen gas produced = 0.003 grams
When subtracting or adding uncertainties, we add the absolute uncertainties:
Absolute uncertainty in the mass of water produced = 0.02 grams + 0.003 grams = 0.023 grams
So, the reported mass of water produced, considering the correct number of significant figures, is given as:
7.956 +/- 0.023 grams
To determine the correct number of significant figures, look for the smallest uncertainty among the measurements used in the subtraction. In this case, the smallest uncertainty is 0.003 grams. Therefore, the reported mass of water should have the same number of decimal places as the uncertainty with the smallest number of decimal places. Hence, the correct number of significant figures for the mass of water produced is three.
Therefore, the final answer is 7.96 grams with the correct number of significant figures.