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The coefficient of volume expansion of glycerine is `49 xx 10^(-5)//^(@)C`. What is the fractional change in its density (approx.) for `30^(@)C` rise in temperature? |
Answer» Coefficient of volume expansion of glycerin, `α_(V) = 49 × 10^(–5) K^(–1)` Rise in temperature, `ΔT = 30^(@)C` Fractional change in its volume `=(DeltaV)/(V)` This change is related with the change in temperature as: `(DeltaV)/(V)=a_(V)DeltaT` `V_(T2)-V_(T1)=V_(T1)a_(V)DeltaT` `(m)/(P_(T2))-(m)/(P_(T1))=(m)/(P_(T1))a_(v)DeltaT` Where, m = Mass of glycerine `P_(r1)`=Initial density at `T_(1)` ∴Fractional change in the density of glycerin = 49 ×10–5 × 30 = 1.47 × 10–2`P_(r_(2))"= Final density at" T_(2)` `(P_(r_(1))-P_(r_(2)))/(P_(r_(2)))a_(v)DeltaT` Where, `(P_(r_(1))-P_(r_(2)))/(P_(r_(2)))`=Fraction change in density ∴Fractional change in the density of glycerin `= 49 ×10^(–5) × 30 = 1.47 × 10^(–2)` |
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