Question

A sample of phosphorus has 0.5 moles of p4 molecules.1. How many p4 molecules are there?2. How many p atoms are there?3. How many molea of p atoms are there in the sample?4.what is the mass of the sample?

Answer 1

Dear student,


1. Since, 1 mol of P₄ contains $6.022\times {10}^{23}$ molecules.
0.5 mol will contain $\left(6.022\times {10}^{23}\times 0.5\right)$ molecules = 3.011 x 10²³ molecules


2. Since 1 molecule of P₄ contains 4 atoms,
so, 3.011 x 10²³ molecules will have $\left(3.011\times {10}^{23}\times 4\right)=12.044\times {10}^{23}atoms$


3. Mole of P atom = Number of atoms in one P₄ molecule $\times$ Mole of P₄
= 4 $\times 0.5$ = 2 mole


4. Mass of the sample = Number of moles of P₄ $\times$ Molar mass of phosphorus molecule
= 0.5 $\times 4\times MolarmassofPatom$
= $0.5\times 4\times 31g$
= 62 g

Regards