Question

Calculate the number of moles in 2.57g of As

Answer 1

Given Mass=2.57g

Molecular Mass of As=75 (approx)

Moles=  2.57/

             75

=0.03 Na

Answer 2

Answer:

Mass of MnO2 = 95g

Mass of one mole MnO2 = 86.94g

Number of moles formula is

Number of moles = Mass of substance / Mass of one mole

Number of moles = 95 / 86.94

Number of moles = 1.092 mol