1. d.4.125 x 10²⁴ atoms
2. c. 487.73 g
Further explanation
The mole is the number of particles(molecules, atoms, ions) contained in a substance
1 mol = 6.02.10²³ particles
Can be formulated
N=n x No
N = number of particles
n = mol
No = Avogadro's = 6.02.10²³
1. 7 moles of phosphorus, so n=7, then number of atoms :
[tex]\tt N=7\times 6.02\times 10^{23}\\\\N=4.215\times 10^{24}[/tex]
2. 2.5 moles of Pt, so n=2.5, the mass of Pt(MW=195,084 g/mol) :
[tex]\tt mass=mol\times MW\\\\mass=2.5\times 195,084\\\\mass=487.73~g[/tex]
