A25.00 ml flask contains methane (ch4) gas at 22.5°c. the pressure in the flask is 225.2 mmhg. how many moles of methane are in the flask?

Answer;

= 0.232 moles

Explanation;

Using the ideal gas Law ;

n = PV/RT ; Where, R is the ideal gas constant (0.0821 L atm / K mole), n is the number of moles, P is the pressure, V is the volume and T is the temperature.

V = 0.025 L, T = 22.5 +273 = 295.5 K, P = 225.2 mmHg

n = (225.2 × 0.025)/(295.5 × 0.0821 )

  = 0.232 moles

The problem here is that according to aufbau principle before 3d orbital 4s subshell comes.after filling 3p orbital with electrons you have 4 electrons left, you place two in 4s with opposite spin and the other two in 3d in any of its two orbitals of total five orbitals with the same spin.

Idon't see the pic?