How many molecules of O2 will be required to produce 28.8 g of water? 2H2 + O2 ---> 2H2O
A)4.28x10^23
B)9.64x10^23
C)1.81x10^23
D)3.61x10^23

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.  

your answer is a. the enthalpy of formation for a pure element in its standard state is always positive.