Answer:a)p4=0.75mol
H2=4.5mol
B)PH3=1×10^7mole
P4=0.25×10^7mole
H2=1.5×10^7mole
Time taken for 3mol of phosphine to react is 54 ×10^7s
Explanation:From the balanced chemical equation
4PH3____P4+6H2
From Gay lussac law ,when gases combines
,They do so in a ratio which bear a simple ratio with their products,if gases.
So it means from the equation above
4 mol of PH3 will form 1mol of P4 and 6 mol of H2
Meaning that if 4mol of PH3 gives 1mol of P4
Then 3mol of PH3 will give 1/4 mol or 0.75 mol of P4 .
In the same vein,3mol of PH3 will give 6×3/4 mol of H2= 4.5 Mol of H2
B) molar concentration =mole/volume
Meaning mole=molar concentration ×volume
Molar concentration is given as 5Km/m^3=5000mol/m^3
Volume=2L =2×1000=2000m^3
Nos of moles=5000×2000=10^7moles
So for P4,nos of moles =1/4×10^7=0.25×10^7
ForH2 ,6/4 ×10^7=1.5×10^7 moles
Rate= volume/time
Time taken for reaction will be volume/rate=2000/3.715×10^6
=54×10^7s