Consider the chemical equations shown here. 2 equations. 1: 2 upper H subscript 2 (g) plus upper O subscript 2 (g) right arrow 2 upper H subscript 2 upper O (g). Delta H 1 equals negative 483.6 kilojoules divided by 2 equals negative 241.8 kilojoules per mole. 2: 3 upper O subscript 2 (g) right arrow 2 upper O subscript 3 (g). Delta H 2 equals 284.6 kilojoules divided by 2 equals 142.3 kilojoules per mole. What is the overall enthalpy of reaction for the equation shown below? 3 upper H subscript 2 (g) plus upper O subscript 3 (g) right arrow 3 upper H subscript 2 upper O (g).

in the given question, the partial pressure is calculated by using the ideal gas equation, that is, pv = nrt

here, p is pressure, v is volume = 25 l, n is number of moles = 0.0104 moles, r is gas constant = -0.0821 l.atm / mol.k

t is temperature = 273 k

p = nrt / v

p = (0.0104 mol × 0.0821 l.atm / mol.k × 273 k) / 25 l

= 0.0093 atm

"among the transition metal elements, manganese and zinc have a slight lowering of electronegativities. the reason behind this is that the nuclear charges of these elements are slightly weaker than the other transition metal elements due to the way their valence electrons are filled up. both manganese and zinc have their valence electrons filled up to the 4th shell with 1 pair of electrons (4s2) completely occupying it. although the electrons in the 3rd shell (3d) are yet to be paired since the outer most shell is filled up, the ability of the nucleus to attract electrons is lessened. hence,   the electronegativity (or the ability to attract electrons) is lessened."