The mass of the CuSO4 x 5H2O sample is 1.664 g. The mass of the recovered copper is 1.198 g.
1. Compute the experimental percent by mass of copper in the sample:
1.1664/1.998x 100=71.81%
2. Calculate the percent copper in pure copper sulfate pentahydrate(this is the theoretical percent copper). One mole of copper has a mass of 63.55 g, and by addition, one mole of CuSO4 x 5H2O has a mass of 249.5 g:
63.55/249.5x100= 25.47%
3. In order to calculate the error of the % Cu and the percent error of the % Cu I know I am suppose to use 1.198 as the experimental value, but I am not sure what to use for the true value.
Something is haywire here.
mass sample = 1.664 g.
mass recovered Cu = 1.198 g.
percent Cu = (1.198/1.664)*100 = 71.995 which I would round to 72.00 to four s.f.
I don't know where you obtained 1.1664 nor 1.998. Check my work.
For percent error.
[(exp value - theoretical value)/theoretical value]*100 = ??
The 25.47% is the theoretical value; i.e., what it's supposED to be.
A mixture of two metals is analyzed by reacting it with dioxygen to completely convert the metals to their oxides. When 1.4850 grams of a nickel/chromium mixture is reacted, it produces 2.0759 grams of a mixture of Cr203 and NiO. What is the mass percent for each metal in the original mixture? Please help!
To calculate the error in the experimental percent by mass of copper (% Cu), you need to compare it to the theoretical percent copper in pure copper sulfate pentahydrate. In this case, the true value or theoretical value is the percent copper in pure copper sulfate pentahydrate. According to your calculations in step 2, the theoretical percent copper is 25.47%.
To calculate the error, you can use the formula:
Error = | Experimental value - True value |
In this case, the experimental value is 71.81% (as calculated in step 1) and the true value is 25.47% (as calculated in step 2). So the error in the percent Cu can be calculated as:
Error % Cu = | 71.81 - 25.47 |
To calculate the percent error of the % Cu, you need to divide the error by the true value and multiply by 100:
Percent Error % Cu = (Error % Cu / True value) x 100
So, using the values calculated above:
Percent Error % Cu = ( | 71.81 - 25.47 | / 25.47 ) x 100