# Chemistry

posted by .

Hw many minutes will it take a current of 31.559 Amperes to deposit 1.722 grams of aluminum?

I believe it to be 6.505 minutes

Is this correct? If not, I'll post my work. Thanks

I found 9.757 minutes.

Ok, here's my work, I just plugged in numbers to another problem, I hope this makes sense:

Convert grams to moles:
1.722g x 1g/26.981538mol =.0638214174mol
.0638214174mol x 2 = .1276428349 mol e-
.1276428349 mol e- x 965000 = 12317.53C
t = 12317.53C/ 31.559
t = 6.505

If you don't mind, can you explain where I went wrong. thanks

I tried copying this so I could mark the lines for errors but for some reason I can't copy it. I'll just explain it and you follow along.

#1. You used 2 for the number of electrons. Al is trivalent and the reaction is Al3+ + 3e = Al. That is a major source of your error.

#2. I used 96485 for coulombs in an ampere instead of 96,500. If you are carrying so many decimal places as you show, then you should not round to 96,500; however, this is a minor source of error.

#3. You don't show the conversion to minutes, but I see your work reflects that.

So your 0.12764 will be 0.19146
and that times 96485 = 18,473
and that divided by 31.559 = 585.34 sec and that divided by 60 = 9.76 min.
Check my arithmetic

I didn't obey all the rules for significant figures. You should go through and round the final answer to the right number of s.f. Since 1.722 g has 4 s.f. I think you are allowed 4 in the answer if you use 96,485 and not 96,500.
Also, I forgot to mention that you have one too many zeros on 96500 but that is just a typo since the number doesn't reflect that extra zero.

Yeah I had a lot of errors. Thanks for explaing that.

## Similar Questions

1. ### Chem

How many minutes will it take a current of 66.049 Ampères to deposit 86.825 grams of aluminum (26.981538 g/mol)?
2. ### Chem

How many grams of nickel can be produced by passing a current of 15.0A through aqueous nickel(II) chloride for 80.0 minutes?
3. ### Chemistry

A solution of H2SO4 was electrolyzed using the inert platinum electrodes. A) Write the balanced half-reactions for the anode and cathode in this cell. B) How many coulombs passed through the cell in 90 minutes at 8.0 amperes?
4. ### AP Chemistry

An unknown metal M forms a soluble compound, M(NO3)2. A solution of M(NO3)2 is electrolyzed. When a constant current of 2.5 amperes is applied for 35 minutes, 3.06 grams of the metal M is deposited. Calculate the molar mass of M and …
5. ### Stitistics

An oil change company advertises that they can change the oil in your car in 15 minutes. Based on the data collected below, what is the probability that oil change will take more than 15 minutes?
6. ### science

If the half-life of a 20.0g is known to be 24 minutes, how long will it take for only 5.0 grams of the sample to remain A.6 minutes B.24 minutes C.48 minutes D.96 minutes I NEED HELP!!!!
7. ### math

Vanessa typically works 8 hours per day in a normal 5 day work week. Last week, however, Vanessa had to take 90 minutes off on Tuesday, 45 minutes off on Thursday, and she left two and a half hours early on Friday. How many hours did …
8. ### math

6. If each of eight biology classrooms is in use for 5 hours and 15 minutes per day, and total of 84 student experiments are done, how long does each experiment take on average?
9. ### chemistry

How many minutes does it take to form 10L of O2 measured at 92.2 kPa and 28°c from water if a current of 1.3 A passes through the electolytic cell?
10. ### Chemistry

How many minutes does it take to form 10L of O2 measured at 92.2 kPa and 28°c from water if a current of 1.3 A passes through the electolytic cell?

More Similar Questions