## Trending News

# 理化 題目的答案是不是算錯阿？（英文）

各位大大～ 這幾題的答案是不是有給錯？ 如果有請給我正確答案 如果沒錯，請解給我看好嗎？ 感謝

（題目都是有關energy的）

1. Some hot tea has cooled from 95℃ to 23℃. Calculate the energy released in joules(J) if the sample of tea has a mass of 50.0g . Assume that the tea has the same specific heat（比熱） as water, 1.00 cal/g℃.

Ans: 15000 J

2. What is the heat energy in joules released when 15.0 g of gold cools from 215℃to 35℃ ? Ans:350 J

3. An ice cube tray is filled with 125 g of water and placed in a freezer. How many joules of heat are removed by the freezer compartment to form ice cubes at 0℃. Ans:42000 J

4. When 0.02 oz of a milk-chocolate candy bar undergoes combustion in a calorimeter, the temperature of 500.0 g of water rises from 18℃ to 76℃. How many kilocalories are available in 1.00 oz of milk chocolate ? Ans:150kcal

### 1 Answer

- FrankLv 71 decade agoFavorite Answer
Some hot tea has cooled from 95℃ to 23℃. Calculate the energy released in joules(J) if the sample of tea has a mass of 50.0g . Assume that the tea has the same specific heat（比熱） as water, 1.00 cal/g℃.

解： H＝50*1*(95-23)＝3600 cal

因1 cal＝4.18 J，所以3600 cal＝15048 J，大約為15000 J

What is the heat energy in joules released when 15.0 g of gold cools from 215℃to 35℃？

解： H＝15*0.0309*(215-35)＝83.4 cal

因1 cal＝4.18 J，所以83.4 cal＝348.7 J，大約為350 J

An ice cube tray is filled with 125 g of water and placed in a freezer. How many joules of heat are removed by the freezer compartment to form ice cubes at 0℃.

解： H＝125*80＝10000 cal

因1 cal＝4.18 J，所以10000 cal＝41800 J，大約為42000 J

When 0.02 oz of a milk-chocolate candy bar undergoes combustion in a calorimeter, the temperature of 500.0 g of water rises from 18℃ to 76℃. How many kilocalories are available in 1.00 oz of milk chocolate？

解： H＝500*1*(76-18)＝2900 cal

2900*1/0.02＝145000 cal＝145 Kcal

Ans: 大約為150 kcal。