A volumetric flask made of Pyrex is calibrated at 20.0^∘ C . It is filled to the 100-mL mark wit

step 1 Alright, let's look at the change of volume due to a temperature change in acetone. So first of

A volumetric flask made of Pyrex is calibrated at 20.0^∘ C ....

A volumetric flask made of Pyrex is calibrated at $20.0^{\circ} \mathrm{C} .$ It is filled to the $100-\mathrm{mL}$ mark with $35.0^{\circ} \mathrm{C}$ acetone. After the flask is filled, the acetone cools and the flask warms so that the combination of acetone and flask reaches a uniform temperature of $32.0^{\circ} \mathrm{C} .$ The combination is then cooled back to $20.0^{\circ} \mathrm{C}$ . (a) What is the volume of the acetone when it cools to $20.0^{\circ} \mathrm{C}$ ? (b) At the temperature of $32.0^{\circ} \mathrm{C},$ does the level of acetone lie above or below the 100 -mL mark on the flask? Explain.

Key Concepts

Thermal Expansion

Thermal expansion is the phenomenon where materials increase in size or volume when heated and decrease when cooled due to changes in molecular motion. This concept is critical for understanding how both liquids and solids respond to temperature variations.

Coefficient of Thermal Expansion

The coefficient of thermal expansion is a material-specific constant that quantifies the change in dimension (length, area, or volume) per unit temperature change. It serves as a key parameter in predicting how much a substance will expand or contract when its temperature varies.

Thermal Expansion of Liquids

Liquids typically have higher coefficients of thermal expansion compared to solids, meaning that their volume can change significantly with temperature. This is important in practical measurements since the actual volume occupied by a liquid can differ from its calibrated value when the temperature deviates from the calibration temperature.

Thermal Expansion of Solids

Solids, such as glass, also undergo thermal expansion, although usually to a lesser extent than liquids. In calibrated devices like volumetric flasks, the expansion of the container must be taken into account because it affects the correspondence between the marked volume and the actual volume of the contained liquid.

Calibration of Volumetric Glassware

Volumetric glassware is calibrated at a specific temperature, meaning the volume markings are accurate only at that designated temperature. When the temperature changes, both the container and the liquid may expand or contract, leading to deviations in the measured volume, which must be corrected for precise work.

Relative Expansion Effects

When both a container and its liquid contents experience thermal expansion, the overall effect on measured volume depends on the relative expansion coefficients of each material. The interplay between these expansions determines whether the liquid level will lie above or below the calibration mark at temperatures different from the calibration temperature.

Transcript

Please give Ace some feedback