Consider the chemical reaction represented by the equation below: 3 MgCl2 + 2 Al = 3 Mg + 2 AlCl3
If 12 moles of magnesium chloride react with enough aluminum, how many moles of aluminum chloride are produced?

3 MgCl2 + 2 Al = 3 Mg + 2 AlCl3

Since we know that we have 12 moles of MgCl2 and enough Al, we don't need to figure out the exact amount of Al.

3 MgCl2 / 2 AlCl3  =  12 mol MgCl2 / x mol AlCl2

cross-multiply

3 MgCl2(x mol AlCl2)  =  12 mol MgCl2(2 AlCl3)

3x = 24

x=8

8 moles AlCl3

Alternatively, we know that we have 12 moles of MgCl2, and a coefficient of 3. This indicates a multiplier of 4 for the entire equation, meaning 2 AlCl3 multiplied by (4) = 8 moles

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.  

the answers would be

the first one and the second one