Question
__ 4. A beaker has 100 g of water.The amount of energy needed to raise the temperature of the water 5^circ C is approximately A 420J/gcdot ^circ C B 210J/gcdot ^circ C C. 2100J/gcdot ^circ C D 1000J/gcdot ^circ C
Solution
3.7
(296 Votes)
Jasper
Elite · Tutor for 8 years
Answer
Here's how to solve this problem:1. **Understand the concept:** We need to use the specific heat capacity of water, which tells us how much energy is needed to raise the temperature of 1 gram of water by 1 degree Celsius. The specific heat capacity of water is approximately 4.2 J/g°C. This means it takes 4.2 Joules of energy to raise the temperature of 1 gram of water by 1 degree Celsius.2. **Apply the formula:** The formula for calculating heat energy (Q) is: Q = m * c * ΔT Where: * Q = heat energy (Joules) * m = mass (grams) * c = specific heat capacity (J/g°C) * ΔT = change in temperature (°C)3. **Plug in the values:** * m = 100 g * c = 4.2 J/g°C * ΔT = 5°C Q = 100 g * 4.2 J/g°C * 5°C Q = 2100 J4. **Answer:** The amount of energy needed is 2100 J. Therefore, the closest answer is **B**. Note that the question seems to have mixed up the units in the options. The correct unit for energy is Joules (J), not J/g°C. The question likely intends to ask for the total energy, which is 2100 J.