Question

Density of an alloy ( =8.17 mathrm{g} / mathrm{cm}^{3} )
Volume of an alloy ( =10.0 mathrm{cm} times 20.0 mathrm{cm} )
( times 15.0 mathrm{cm}=3000.000 mathrm{cm}^{3} )
Mass of an alloy =
Density ( times V ) olume ( =8.17 g / mathrm{cm}^{3} times 3000.000 mathrm{cm}^{3}=24,510 mathrm{g} )
Percentage of nickel in alloy ( =45.8 % )
Mass of nickel=
( 24,510 g times frac{45.8}{100}=11,225.58 g )
Moles of nickel = ( frac{112,225.58 g}{58.69 g / m o l}=191.2690 mathrm{mol} )
Number of atoms of nickel:
( 191.2690 times 6.022 times 10^{23}=1.1518 times 10^{26} ) atoms
The number of Ni atoms present in the alloyis ( 1.1518 times 10^{26} ) atoms.

# (ii) An alloy of iron (53.6%), nickel (45.8%) and mangnese (0.6%) has a density of 8.17g cm-3. Calculate the number of Ni atoms present in the alloy of dimensions 10.0 cm x 20.0 cm x 15.0 cm. 3

Solution