Question

76.5g of sodium carbonate was dissolved in 1dm3 water at 12C. If the density of the solution at these temperature is 2.08gcm3. Find the molar concentration.​

Answer 1

$\sf\purple{Given:-}$

$\: \: \: \: \: \: \: \: \: \: \: \rm\bullet{ \: m \: = \: 76.5 \: g}$

$\: \: \: \: \: \: \: \: \: \: \: \rm\bullet{ \: water \: = \: 12c}$

$\sf\purple{Find:-}$

• . Find the molar concentration.

$\sf\purple{Solution:-}$

$\longmapsto\rm{Mole \: = \: \frac{76.5}{106} = 0.722 \: mole}$

$\longmapsto\rm{volume = \: 1l}$

$\longmapsto\rm{density = 12.08 \: \frac{g}{cm} ^{2} }$

Using formula :-

$\: \: \: : \longmapsto \boxed{ \rm \: density \: = \frac{volume}{density} }$

$\: \: :\longmapsto\boxed{ \rm \: mass = \frac{volume}{density} }$

Now,

$\longmapsto\rm{ \frac{1100}{2.08} }$

$\longmapsto\rm \fbox{ \rm{480.77 \: g}}$

So,

Now find the molabity :

$\longmapsto\rm{ \frac{0.722}{48.77} \: \times \: 1100}$

$\longmapsto\rm \fbox \purple{1.50 \: m}$

$\rule{259mm}1mm$

LEARN MORE :-

$\boxed {\begin{array}{|c|c|c|c|cccc|}\sf {}\bf \underline{Element} & \bf \underline{Symbol} & \bf \underline{Valency} & \bf \underline{Atomic\:Number} & & \bf \underline{Electron} & \bf \underline{Configuration} & \\ \sf {} &&&&\bf K&\bf L &\bf M&\bf N \\ \sf{}\rm Hydrogen &\sf H & 1 & 1 & 1 &&& \\ \sf{}\rm Helium &\sf He & 0 & 2 & 2 &&& \\ \sf{}\rm Lithium &\sf Li & 1& 3 &2 &1 && \\ \sf{}\rm Beryllium &\sf Be & 2 & 4 & 2 & 2 && \\ \sf{}\rm Boron &\sf B & 3 & 5 & 2 & 3 && \\ \sf{}\rm Carbon & \sf C & 4 & 6 & 2 & 4 && \\ \sf{}\rm Nitrogen &\sf N & 3 & 7 & 2 & 5 && \\ \sf{}\rm Oxygen &\sf O & 2 & 8 & 2 & 6 && \\ \sf{}\rm Fluorine &\sf F & 1 & 9 & 2 & 7 && \\ \sf{}\rm Neon & \sf Ne & 0 & 10 & 2 & 8 && \\ \sf{}\rm Sodium &\sf Na & 1 & 11 & 2 & 8 & 1 &\\ \sf{}\rm Magnesium &\sf Mg & 2 & 12 & 2 & 8 & 2 & \\ \sf {}\rm Aluminium &\sf Al & 3 & 13 & 2 & 8 & 3 & \\ \sf{}\rm Silicon &\sf Si & 4 & 14 & 2 & 8 & 4 & \\ \sf {}\rm Phosphorus &\sf P & 3 & 15 & 2 & 8 & 7 & \\ \sf {}\rm Sulphur &\sf S & 2 & 16 & 2 & 8 & 8 & \\ \sf{}\rm Chlorine &\sf Cl & 1 & 17 & 2 & 8 & 8 &1 \\ \sf{}\rm Argon &\sf Ar & 0 & 18 & 2 & 8 & 8 & 2 \\ \sf {}\rm Potassium &\sf K & 1 & 19 & 2 & 8 & 8 &3 \\ \sf{}\rm Calcium &\sf Ca & 2 & 20 & 2 & 8 & 8 & 4 \\ \sf{} \end {array}}$

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