How many liters of a 18.0M stock solution of NaCl are needed to make 2.0L of a 2.5M solution? Your
•54L
•28L
•22.5L
•14.4L

0.28 L

Explanation:

From the question given above, the following data were obtained:

Molarity of stock solution (M₁) = 18 M

Volume of diluted solution (V₂) = 2 L

Molarity of diluted solution (M₂) = 2.5 M

Volume of stock solution needed (V₁) =?

The volume of the stock solution needed can be obtained as follow:

M₁V₁ = M₂V₂

18 × V₁ = 2.5 × 2

18 × V₁ = 5

Divide both side by 18

V₁ = 5 / 18

V₁ = 0.28 L

Thus, the volume of the stock solution needed is 0.28 L

2fe + 3h2so4 -> fe2(so4)3 + 3h2

it is necessary to balance equations in order to get the proper amount of reactants as well as products in order not to make a miscalculation.

you cannot change the subscripts as that would change the substance itself. for instance, diatomic elements such as h2 only have the subscript two when a gas. another example would be so4, if you were to change the subscript, the element would no longer be sulfate.

we change the coefficients instead as that only changes the number of molecules rather than the substance itself.

hope this !