Which of the following substances conducts electricity? A. A block of salt
B. Distilled water
C. Sugar
D. Vinegar

a

Explanation:

salt and energy can cause reactions to produce electricity

The answer is A

Explanation:  An electrolyte solution has the ability to conduct electricity because when a salt dissolves, its dissociated ions can move freely in solution, allowing a charge to flow. Electrolyte solutions are normally formed when a salt is placed into a solvent such as water. (Google  Source If needed)

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

it is stable as it is in group 0 which have full outer shells of electrons