Chemistry please help!? need urgent!

Ask Your Question

Chemistry please help!? need urgent!



Please help me on this problem. How would I solve this: 
Twelve-gauge copper wire,like the kind commonly used in residential electrical systems, is roughly cylindrical and has a diameter of approximately .1040in. Copper's density is 8.92g/cubic cm and copper atoms have an approximate atomic radius of 135 pm. 
a.Calculate the number of atoms it would take to span the thickness, that is, diameter, of one of these wires. Express this value as a number of atoms and a number of moles to atoms. 
b.calculate the mass,in grams, of a 100ft piece of copper wire. 
c.How many moles of copper atoms would be found in a piece of this wire that is exactly 100ft long? How many atoms?



Answer this Question:

Close

Close

Posted Answers:

a. 
(0.1040 in) × (2.54 × 1010 pm/in) / (135 pm/atom) = 19567407 = 1.96 × 107 atoms 

(19567407 atoms) / (6.022 x 1023 atoms/mol) = 3.25 × 10-17 mol 

b. 
((0.1040 in / 2) x (2.54 cm/in))2 × (100 ft × 30.48 cm/ft) × (8.92 g/cm3) = 474.3 = 474 g