Question

उदाहरण 1.8
3 M Nacl विलयन का घनत्व 1.25g ml है इस
विलयन की मोललता का परिकलन कीजिए।​

Answer 1

$\huge\sf\bold\pink{\underline{ANSWER:-}}$

For NaCl Solution -

$\sf{Molarity \: (M) = 3 \: Molar}$

$\sf{Density \: (d) = 1.25 g/ml}$

$\sf{Molar \: mass \: of \: NaCl (M1)= 23 + 35.5 = 58.5 \: g/mol}$

We know -

★ Relation between molarity , molality & density -

$\sf{m =\dfrac{1000\times M\times d}{1000 - M(M1)}}$

$\sf{m =\dfrac{1000\times 3\times 1.25}{1000 - 3\times 58.5}}$

$\sf{m =\dfrac{1000\times 3.75}{1000 - 175.5}}$

$\sf{m =\dfrac{3750}{824.5}}$

$\sf{m =\dfrac{37500}{8245}}$

$\sf{m =\dfrac{7500}{1649}}$

$\sf{m = 4.55 \: molal}$

$\sf{Molality \: of \: NaCl \: solution \: is \: 4.55 \: molal. }$

Answer 2

Answer:

For NaCl Solution -

\sf{Molarity \: (M) = 3 \: Molar}Molarity(M)=3Molar

\sf{Density \: (d) = 1.25 g/ml}Density(d)=1.25g/ml

\sf{Molar \: mass \: of \: NaCl (M1)= 23 + 35.5 = 58.5 \: g/mol}MolarmassofNaCl(M1)=23+35.5=58.5g/mol

We know -

★ Relation between molarity , molality & density -

\sf{m =\dfrac{1000\times M\times d}{1000 - M(M1)}}m=

1000−M(M1)

1000×M×d

\sf{m =\dfrac{1000\times 3\times 1.25}{1000 - 3\times 58.5}}m=

1000−3×58.5

1000×3×1.25

\sf{m =\dfrac{1000\times 3.75}{1000 - 175.5}}m=

1000−175.5

1000×3.75

\sf{m =\dfrac{3750}{824.5}}m=

824.5

3750

\sf{m =\dfrac{37500}{8245}}m=

8245

37500

\sf{m =\dfrac{7500}{1649}}m=

1649

7500

\sf{m = 4.55 \: molal}m=4.55molal

\sf{Molality \: of \: NaCl \: solution \: is \: 4.55 \: molal. }MolalityofNaClsolutionis4.55molal.