When a 0.66-g sample of olive oil is burned in a calorimeter, the heat released increases the temperature of 370 g of water from 22.7 °C to 38.8 °C. What is the energy value for the olive oil in kcal/g? (3.5, 3.6)

Verified step by step guidance

1. Identify the known values: mass of water (m) = 370 g, initial temperature (T1) = 22.7 °C, final temperature (T2) = 38.8 °C, specific heat capacity of water (c) = 4.18 J/g°C.
2. Calculate the change in temperature (ΔT) of the water using the formula ΔT = T2 - T1.
3. Use the formula q = m * c * ΔT to calculate the heat absorbed by the water, where q is the heat absorbed.
4. Convert the heat absorbed by the water from joules to kilocalories using the conversion factor 1 kcal = 4184 J.
5. Determine the energy value of the olive oil in kcal/g by dividing the heat absorbed (in kcal) by the mass of the olive oil sample (0.66 g).

Key Concepts

Calorimetry

Calorimetry is the science of measuring the heat of chemical reactions or physical changes. In this context, it involves using a calorimeter to determine the amount of heat released when a substance, like olive oil, is burned. The heat absorbed by the water in the calorimeter is used to calculate the energy content of the sample.

Specific Heat Capacity

Specific heat capacity is the amount of heat required to raise the temperature of a unit mass of a substance by one degree Celsius. For water, this value is typically 4.18 J/g°C. Understanding this concept is crucial for calculating the heat absorbed by the water when the olive oil is burned, as it allows for the conversion of temperature change into energy.

Energy Value Calculation

The energy value of a substance is calculated by determining the total heat released during combustion and dividing it by the mass of the substance burned. In this case, the heat absorbed by the water is used to find the energy released by the olive oil, which is then expressed in kilocalories per gram (kcal/g) to provide a standardized measure of its energy content.