才考試第三天, 便差點在考試途中哭了出來

剛才在學校發生了一些事...現在很不舒服

只好死撐下去...

還有多少天才完......

這幾天都累透了. 頭暈手震心悸全身沒力肚痛腦內一片空白頭痛失眠呆滯......... 只有一個殘字可以形容

向全級總成績50名/ Chem全級頭10 出發

Physics 第三課的notes...我不打了...主要都是溫真空煲 / 對流/ radiation

明天預告: Bio / Maths Notes

那篇作文我明天交給你

n          Latent Heat

 

u        Change of potential energy of substance particle

 

u        During changing state

 

n          When substance changing state

 

u        Latent Heat: absorbed/ released

 

u        X changing substance's temp.

 

n          Specific Latent Heat

 

u        Fusion ice (lf)

 

l          Energy needed to change 1kg ice →water

 

l          X change of temp.

 

l          3.34 x 10^5  J kg^-1

 

u        Vaporization of water (lv)

 

l          Energy needed to change 1kg water →steam

 

l          X change of temp.

 

l          2.26 x 10^6  J kg^-1

 

n          Evaporation

 

u        Fast-moving particles

 

u        Escaping from surface of liquid

 

u        Change of liquid →vapour

 

l          Temp. < Boiling point

 

u        Rate of evaporation↑

 

l          Temp. & surface area of liquid↑

 

l          Density of vapour/ Humidity of air↓

l           Movement of vapour↑

 Change of states (把這圖背掉, 但不用背 sublimation 跟 Deposition)

Cooling curve (較大機會要你看圖答問題)

E.g. cooling curve of naphthalene 萘

 

AB – liquid cooling

 

BC – liquid solidification (轉state, liquid → Gas)

 

CD – solid cooling to room temp.

 

n            AB drops steadily.

 

u   Shows ↓temp. of liquid

 

n            BC is flat

 

u    Temp. remains constant

 

u    Substances solidifying

 

n            CD Drops steadily

 

u    Shows ↓temp. of liquid

Freezing point: read from flat part BC of the curve (E.g.: 80℃)

• Heat Capacity (C)

   

n            Energy transferred to ↑ 1℃ of the obj.

u          Heat capacity = mass x specific heat capacity

u          C = mc

u          Unit: J ℃^-1

• Specific heat capacity (c)

   

n            Energy transferred to ↑ 1℃ of 1 kg obj.

u          Energy transferred = mass x specific heat capacity x change in temp.

u          E = mc△T

u          Unit: J kg^ -1 ℃^-1

• Mixture ( Long Q 出, 書P.28, Example 7)

   

n            Energy lost by hot body = energy gained by cold body

n            會問main errors

l            Heat loss to surroundings

l            Some energy is used to heat up polystyrene cup, stirrer & thermometer

n            led to experimental value ＞ actual value

n            之後會問點樣 improve accuracy of experiment

→ Wrap the polystyrene cup with cotton wool

→ 有可能MC/ LONG Q出, 看書就可