2 Specific Heat (8) During the course of an atermoon at the beach 50,000l aules

Question

2 Specific Heat (8) During the course of an atermoon at the beach 50,000l aules of energy are received per kg of seawater and sand. Show your work, or no credit will be givern. Specific Heat of sand 2,000 Joules/kg/ oC Specific Heat of seawater 5,000 Joules/kg/C Initial temperature of sand 22 °C Initial temperature of seawater 9 C a) What temperature will the sand be at the end of the day in oC? (2) b) What temperature will the seawater be at the end of the day in oC? (2) c) Given that the heat of vaporization is 540 calories, the heat of fusion is 80 calories and the specific heat of water is 1 calorie/g/°C, rank the following from the LEAST to the MOST energy required. (1-least energy, 4- most energy). Show your work, or no credit will be given. (4) Evaporate 0.5 g water at 100°C Melt 2 g water at 0°c Change temperature of 3 g water from 20°C to 70°C Change temperature of 5 g water from 10°C to 20°C

Explanation / Answer

(a) Q = S(T2-T1)

or, 50000 = 2000 (T2-22)

or, T2 = 25+22 =47oC

(b) Q = S(T2-T1)

or, 50000 = 5000 (T2-9)

or, T2 = 19oC

(c) Q = ML(For phase change at a temp.)

0.5 x 540 =270calories to evaporate 0.5g of water at 100oC

2 x 80 = 160 calories to melt 2g of water at 0oC

Q = MC(T2-T1) [For temp change]

3 x 1 x (70 - 20) = 150 calories to change temp of 3 g of water from 20oC to 70oC

5 x 1 x (20 - 10) = 50 calories to change temp of 5g of water from 10oC to 20oC

Arranging them in decending order

1. evaporate 0.5g of water at 100oC

2. melt 2g of water at 0oC

3. change temp of 3 g of water from 20oC to 70oC

4. change temp of 5g of water from 10oC to 20oC

Related Questions

Navigate

• Browse (All)
• Browse 2
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.