Q.A glass flask holds $500\ \text{cm}^3$ of a liquid at $25\,^\circ\text{C}$. If the coefficient of cubical (volume) expansion of the liquid is $\gamma = 9\times10^{-4}\ {}^\circ\text{C}^{-1}$ and the expansion of the flask itself is neglected, find the volume occupied by the liquid when it is heated to $75\,^\circ\text{C}$.

Given: $V_0 = 500\ \text{cm}^3$, $\gamma = 9\times10^{-4}\ {}^\circ\text{C}^{-1}$, $\Delta T = 75-25 = 50\,^\circ\text{C}$.

Using $\Delta V = V_0\,\gamma\,\Delta T$:

So the new volume is $V = V_0 + \Delta V = 500 + 22.5 = 522.5\ \text{cm}^3$.

Find $\Delta T$, compute $\Delta V = V_0\gamma\,\Delta T$, then add $\Delta V$ to $V_0$ to get the final volume (the question says to neglect the container's own expansion, so no correction is needed).

• Reporting only $\Delta V$ ($22.5\ \text{cm}^3$) as if it were the final volume, instead of adding it to $V_0$.
• Applying a correction for the container's own expansion despite being told to neglect it.