Which of the following bond types is normally the weakest? a)sigma bond formed by the overlap of two porbitals b)sigma bond formed by the overlap of two sorbitals c)pi bond formed by the overlap of two porbitals d)sigma bond formed by the overlap of one sand one porbital

Here we have to choose the weakest bond among the given pi and sigma bonds.

The weakest bond among the given options are pi bond formed by the overlap of two p-orbitals.

We know the strength of the covalent bond is approximately proportional to the extent of overlap between the combining orbitals. Greater overlap makes a bond stronger.

There are two types of overlap one is direct overlap and lateral overlap. The direct overlap generates sigma bond whereas the lateral overlap generates pi bonds.

In the direct overlap there are more overlap than the lateral overlap thus any type of sigma bond will be more stronger than the pi bond.

Thus the weakest bond among the given options are pi bond formed by the overlap of two p-orbitals.

as given the equation is

2al + 6 hcl > 2 alcl3 + 3 h2(g)

as per equation two moles of aluminum reacts with six moles of hcl to give two moles of alcl3 and three moles of hydrogen gas

given: three moles of al are present and 7 moles of hcl

for three moles of aluminum nine moles of hcl will be required

however as 7 moles of hcl are present so the limiting reagent is hcl

hcl is going to decide the number of moles of product formed

when six moles of hcl are present = 3 moles of h2 are formed

when one mole of hcl is present == 3/6 mole sof h2 will be formed

when 7 moles of hcl are present = 3 x 7/ 6 moles of h2 will be formed = 3.5 moles of h2