#3. What liquid had the lowest volume expansion at 40^circ C Ethanol Water Salt water Glycerine

To determine which liquid had the lowest volume expansion at $40^{\circ }C$, we need to consider the coefficient of volume expansion for each liquid.<br /><br />The coefficient of volume expansion is a measure of how much the volume of a substance changes with a change in temperature. It is usually expressed in units of $1/^{\circ }C$.<br /><br />Let's compare the coefficients of volume expansion for the given liquids:<br /><br />1. Ethanol: The coefficient of volume expansion for ethanol is approximately $0.00021 / ^{\circ }C$.<br />2. Water: The coefficient of volume expansion for water is approximately $0.00021 / ^{\circ }C$.<br />3. Salt water: The coefficient of volume expansion for salt water depends on the concentration of salt. However, it is generally close to that of pure water, which is approximately $0.00021 / ^{\circ }C$.<br />4. Glycerine: The coefficient of volume expansion for glycerine is approximately $0.00012 / ^{\circ }C$.<br /><br />Based on these values, we can see that glycerine has the lowest coefficient of volume expansion among the given liquids. Therefore, glycerine would have the lowest volume expansion at $40^{\circ }C$.<br /><br />Answer: Glycerine