Question

When 100. mL of 6.00 M HCl is diluted to 300. mL, the final concentration is ________.

A - 3.00 M
B- 12.0 M
C- 2.00 M
D- 18.0 M
E- 1.00 M

Answer 1

The final concentration is 2 M

Step-by-step explanation:

Dilution is the procedure to prepare a less concentrated solution from a more concentrated one. It consists of adding more solvent.

The amount of solute (the solute is the solid, liquid or gaseous substance that dissolves in the solvent to produce a homogeneous mixture known as a solution and is generally found in a smaller proportion) does not vary. The volume of the solvent varies, so that the concentration of the solute decreases, as the volume of the solution increases.

In summary, dilution is a procedure by which the concentration of a solution is decreased, generally with the addition of a diluent.

One way to calculate concentrations or volumes in dilutions is through the expression:

Ci * Vi = Cf * Vf

where

• Ci = initial concentration
• Vi = Initial volume
• Cf = Final concentration
• Vf = Final volume

In this case:

• Ci= 6 M
• Vi= 100 mL= 0.1 L (1 L=1000 mL)
• Cf= ?
• Vf= 300 mL= 0.3 L

Replacing:

6 M* 0.1 L= Cf*0.3 L

Solving:

`Cf=(6 M* 0.1 L)/(0.3 L)`

Cf=2 M

The final concentration is 2 M

Answer 2

2.00 M

Step-by-step explanation:

The concentration of a solution is given by

`M=(m)/(V)`

where

m is the mass of solute

V is the volume of the solution

At the beginning, the solution has:

M = 6.00 M is the concentration

V = 100 mL = 0.1 L is the volume

So the mass of solute (HCl) is

`m=MV=(6.00)(0.1)=0.6g`

Then, the HCL is diluted into a solution with volume of

V = 300 mL = 0.3 L

Therefore, the final concentration is:

`M=(m)/(V)=(0.6)/(0.3)=2.00 M`