i need help in chemistry, i dont get math..more details below?

Question

assume a penny is 1mm thick.
1. if you had 1 mole of pennies, how high would the stack measure in mm?
2. what is that in feet? (remember factor label).

Answer 1

For the second one, take the mm and divide by 2.54 to get it in inches. Then, divide by 12 to get it in feet.

Answer 2

A mole is a quantity of 6.02 x 10^23. So if you had one mole of pennies and they were each 1 mm thick, then the stack would just be 6.02 x 10^23 mm.

To convert this to feet, use the conversion factors:

6.02 x 10^23 mm * (1 cm / 10 mm) * (1 inch / 2.54 cm) * (1 ft / 12 in) =
(6.02 x 10^23) * (1/10) * (1/2.54) * (1/12) =
(6.02 x 10^22) * (1/2.54) * (1/12) =
0.198 x 10^22 = (rounding off)
1.98 x 10^22 feet

Answer 3

1 mole = 6.02 x 10^23 of something

So...

6.02 x 10^23 pennies x 1 mm per penny = 6.02 x 10^23 mm

1000 mm = 3.2808399 feet

6.02 x 10^23 mm / 1000 mm * 3.2808399 feet = 1.975 x 10^21 feet

Answer 4

6.022X10^23*1mm=6.022X10^23mm
For your second question just divide this number 24 (the approximate number of millimeters in an inch).