In the acid-base reaction between Sr(OH)2 and HNO3, 0.75 L of 0.85 M Sr(NO3)2 is
formed upon the reaction of 0.515 L of HNO3
solution and excess Sr(OH)2. What is the
molarity of the initial HNO3 solution?
1. 2.48 M
2. 0.619 M
3. 1.55 M
4. 0.233 M
5. 4.11 M
6. 0.638 M
7. 1.24 M

answer: option (b) is the correct answer.

explanation:

a covalent bond is formed by sharing of electrons. whereas polarity arises due to difference in electronegativity of two atoms.

therefore, more is the electronegativity of an atom which combines with the titanium, more readily it will induce a partial positive and negative charge.

thus, out of the given options fluorine is most electronegative and has an incomplete octet. therefore, it will readily combine with titanium to share the electrons and complete its octet.  

definition

                    entropy is a measure of the randomness or the extent of disorder of a chemical process.

                      enthalpy is a measure of the heat change of a reaction occurring at a constant pressure.

measurement units:

                        entropy is measured in joule per kelvin (jk⁻¹)   whereas enthalpy is measured in joule per mole (jmol⁻¹)

requirements:

                            entropy has no requirements or limits, and its change is measured by the division between the heat change of the chemical process and the temperature.

                              in contrast, enthalpy can only be related to the heat change of the reaction under standard conditions.