A mystery element has 18 protons. Which one of the following statements is true about the element? o
A. The element belongs in row 2 of the periodic table and is classified as a halogen.
O
B. The element belongs in row 3 of the periodic table and is classified as a noble gas.
O
C. The element belongs in row 4 of the periodic table and is classified as an alkali metal.
D. The element belongs in row 5 of the periodic table and is classified as an alkaline earth metal.

i'm assuming that it's c.) red bank..

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 :

the answer is barium and copper bromide