Question

Find the new concentration of a solution if 25.0 mL of water is added to 125.0 mL of 0.150 M NaCl solution. What is the final volume? mL

Answer 1

Answer:

150.0 is the final volume

next question is a

and the next is 0.125 M

Explanation:

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Answer 2

Answer : The correct answer is New concentration = 0.125 M and final volume = 0.150 M

Given :

Molarity of NaCl solution = 0.150 M volume of NaCL solution = 125 mL

Volume of water added = 25 mL

1) Final volume = ? 2) New concentration = ?

1) To find the final volume :

New volume = volume of NaCl solution + volume of water added

= 125 mL + 25 mL

= 150 mL

Converting this final volume from mL to L

1 L = 1000 mL

$Final volume = 150 mL * \frac{1 L}{1000 mL }$

Final volume = 0.150 L

2) To find new concentration :

Following steps can be used :

a) To find mole of NaCl :

Mole of NaCl can be calculated using molarity formula . Molarity can be defined as mole of solute present in Liter of solution (volume ) .It represents Concentration of solution . It used unit as M or $\frac{mol}{L}$ . It can be expressed as :

$Molarity = \frac{mole of solute (NaCl)(mol) }{volume of solution (L) }$

Molarity of NaCl solution = 0.150 $\frac{mol}{L}$

Volume of NaCl solution = 0.125 mL or 0.125 L

Plugging these values in molarity formula

$0.150 \frac{mol}{L} = \frac{mole of NaCl}{0.125 L}$

Multiplying both side by 0.125 L

$0.150 \frac{mol}{L } * 0.125 L = \frac{mol of NaCl}{0.125 L} * 0.125 L$

Mole of NaCl = 0.01875 mol

b) To find New concentration :

Since the mole of NaCl remians same when water is added . Hence new concentration ( molarity )can be calculated using mole of NaCl and final volume .

Mole of NaCL = 0.01875 mol

Final volume = 0.150 L

plugging values in molarity formula :

$New molarity = \frac{0.0.01875 mol }{0.150 L }$

New concentration = 0.125 M