Chemistry hw Help

Question

Calculate the initial number of moles at 77L if the number of moles changed to 5.43 at 86L. Name the law used 

Answer 1

Look at Avogadro's Gas Law:

n1/V1 = n2/V2

n1 = initial number of moles = ?

V1 = initial volume = 77 L

n2 = final number of moles = 5.43

V2 = final volume = 86 L

Solving for n1 we have...

n1 = n2V1 / V2 = (5.43)(77) / (86)

n1 = 4.9 moles (2 sig. figs.)