4 Which statement about an ionic compound is not correct?
A It conducts electricity when dissolved in water.
B It has a high melting point due to strong attractive forces between ions.
с It has a regular lattice of oppositely charged ions in a 'sea of electrons'.
D The ionic bonds are formed between metallic and non-metallic elements.

it conducts electricity when dissolved in water

Explanation:

the water molecules bond to positive and negative ions results to breaking of lattice and it's fixed position broken

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