How many electrons are there in second principal energy
level(n=2) of a phosphorus atom?

8 electrons

Explanation:

Phosphorous is the element of group 15 and third period. The atomic number of chlorine is 15 and the symbol of the element is P.

The electronic configuration of the element phosphorus is:-

Thus, from the electronic configuration shown above,

In n = 2, the total number of electrons are 8 which are present in

answer: the value of enthalpy change will be -152.80 kj.

solution:

pressure = 1atm , temperature = = 298 k

given that pressure and temperature are same in both gases , the number of moles of both gases can be determined by the ideal gas equation.

according to reaction 3 moles no are reacting with 1 mol of ,then 0.49 mol of no will react with moles of ozone that is 0.16 moles of ozone. since, no is limiting reagent and is an excessive reagent.

enthalpy change for the reaction between the given volumes of the gases is :