If you rub a piece of gold, Au, vigorously, you can rub off 2.00 moles of gold atoms in a century. How many minutes are needed to rub off 1.50 micrograms of gold?
-
UP 0 DOWN 0 0 4

4 Answers
Swarna Kamal Dhyawala
·2013-02-04 04:55:40
the answer must be 0.2 min or 12 seconds
Swarna Kamal Dhyawala nearly
Upvote·0· Reply ·2013-02-04 04:56:23
Anurag Ghosh I cant get wat do u mean by 2 moles of gold atoms........Cant we use dat formula- mole=Weight/Molecular weight.......Weight comes to be 394 gms...and then further proceed?????...but my answer is coming something unusual......:P
Swarna Kamal Dhyawala @anurag i m nt sure abt this answer
Jeet Sen Sharma
·2013-02-02 10:24:05
near about 30 mins.
Bitan Chakraborty No.....do it again, even ask your friends to do it.
Swarna Kamal Dhyawala
·2013-02-06 07:44:34
bitan sir is this answer correct??????
Anurag Ghosh How did u get this answer????
Bitan Chakraborty 0.2 mins is the correct answer.
Also I would like u to post the calculation (briefly) for others to understand. Ok?
Anurag Ghosh
·2013-02-06 17:45:39
According to me
2=weight/197...dat gives me 394 gms...
Now we can rub 394 gms of gold in a century(100 years)i.e 100*365*24*60 minutes...
Now using unitary method....
394 gms in 100*365*24*60 mins
1 gm in 100*365*24*60/394 mins
1.5*10^-12 gm in 100*365*24*60/394*1.5*10^-12 mins
Is this process r8?
Swarna Kamal Dhyawala 1 micro gram =1/10^6
proceed using unitary method
Anurag Ghosh ohhhh sry sry...i forfot wat is 1 microgram...:D
Anurag Ghosh forgot