What does it mean for a substance to dissolve?
a. it drops into the solvent.
b. it floats in the solvent.
c. it is absorbed into the solvent.
d. it gets bigger in the solvent.

The answer is: C. It is absorbed into the solvent.

Explanation:

This is because a substance is only soluble in a liquid when it completely disappears when added to the liquid after some agitation.

For example Salt and water. If you add salt to water and stir it for a few seconds, the salt completely disappears.

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

metric time was an attempt to create a standard unit of time based off of 10, but it never took off an is not included in the metric system (si)