You know that an unlabeled water bottle contains at least some water. you measure the freezing point of the unknown substance and find that it freezes at a temperature lower than 0 degrees celsius at 1 atmosphere pressure. which of the following can you conclude?

a. the substance is pure water.

b. the substance will have a boiling point that is less than 100 degrees celsius.

c. the substance will have a vapor pressure that is greater than that of pure water.

d. the substance is an aqueous solution.

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