Final answer:
To heat water using the energy from burning propane, we first calculate the energy produced by the combustion of propane. We then use the heat capacity of water to determine the increase in temperature that can be achieved. In this case, 0.900 pounds of propane can heat approximately 4 kilograms of water from 21.0 °C to 43.8 °C.
Step-by-step explanation:
To determine how many kilograms of water can be heated from 21.0 °C to 43.8 °C using the energy obtained from burning 0.900 pounds of propane, we need to calculate the amount of energy produced by the combustion of propane and then use that to determine the increase in temperature of the water.
First, convert the weight of propane from pounds to grams. 0.900 pounds is approximately 408.2 grams.
Next, calculate the energy produced by the combustion of 408.2 grams of propane using the fuel value of propane, which is 46.3 kJ/g. Multiply the weight of propane by the fuel value: 408.2 grams * 46.3 kJ/g = 18,892.66 kJ.
Finally, use the heat capacity of water to calculate the increase in temperature. The specific heat capacity of water is 4.184 J/g °C. Since there are 1000 grams in a kilogram, the increase in temperature is given by: (18,892.66 kJ * 1000) / (4.184 J/g °C * 4000 grams) = 1.1306 °C. Therefore, the 0.900 pounds of propane can heat approximately 4 kilograms of water from 21.0 °C to 43.8 °C.