Why do scientists use models?

Models make some things easier to understand.
Measurements can be made only on models.
Models help scientists visualize things they can’t see.
Models are perfectly accurate representations of objects.

C. Models help scientists visualize things that they cannot see.

Explanation:

A model is used to help scientists visualize things that they cannot see. A model is used to represent an idea, an object or a process that describes a phenomena. It tends to be thought of a speculation instrument to help structure clarifications.

Models are valuable rearrangements to help understanding. The models are incredible assets however they are legitimate as long as they can clarify the entirety of the accessible information that is from the perceptions and estimations.

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