## Physics for Scientists and Engineers: A Strategic Approach with Modern Physics (4th Edition)

The heat energy $Q$ required to change the temperature of a substance is: $Q = m~c~\Delta T$ The heat energy $Q$ required to change the state of a substance is: $Q = m~L$ We can find the maximum mass of ethyl alcohol that could be boiled. $Q = m~c~\Delta T + m~L$ $m = \frac{Q}{c~\Delta T+L}$ $m = \frac{1000~J}{(2400~J/kg~C^{\circ})(78~^{\circ}C-20~^{\circ}C)+(8.50\times 10^5~J/kg)}$ $m = 0.0010~kg = 1.0~g$ The maximum mass of ethyl alcohol that could be boiled is 1.0 gram.