A 25 milliliter sample of HNO2 (aq) is neutralized by 32.1 milliliters of 0.150 M KOH (aq). What is the concentration of the acid

The answer is (3) 0.193M.

Explanation:

To find the molarity of HNO3, you just need to use the M1V1=M2V2 equation (no need to worry about ionization constants because HNO3 is monoprotic and KOH dissociates 1:1). Since the molarity you are looking for is M1, you get M1=M2V2/V1=(0.150)(32.1)/25.0= 0.193M

the seeing the electronic configuration we can say that the element is fluorine.

fluorine is the most electronegative element in the periodic table.

but by only seeing the configuration we cannot say about its reactivity because we don't know if its configuration after excitation or by addition of electrons.

but if not then, it is the lightest halogen and exists as a highly toxic pale yellow diatomic gas at standard conditions. as the most electronegative element, it is extremely reactive: almost all other elements, including some noble gases, form compounds with fluorine.