A2L Item 109

• Description: Estimate the heat needed to boil a cup of water.
• Goal: Problem solving with thermal energy.
• Source: UMPERG-ctqpe208
• Keywords: Heat, Thermodynamics

---

The question for students:

A cup of water is about 225 grams. The minimum amount of heat needed to boil a cup of water at room temperature for tea is most nearly

1. 10,000 cal
2. 17,000 cal
3. 25,000 cal
4. 31,000 cal
5. None of the above
6. Cannot be determined

---

Commentary for teachers:

Answer

(2) This problem requires that students know the specific heat of water and assume that the water is initially at room temperature.

---