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Contoh Soalan Chemistry

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Contoh Soalan Chemistry
1. | An experiment is carried out to determine the freezing point of naphthalene.Solid naphthalene is heated in a water bath until it melts completely.
The initial temperature is recorded.
Then molten naphthalene is left to cool.
The reading of the temperature is recorded every 30 seconds.
Figure below shows the recorded thermometer readings at 30 seconds intervals.
Satu eksperimen dijalankan untuk menentukan takat beku naftalena. Pepejal naftalena dipanaskan di dalam kukus air sehingga melebur dengan lengkap. Suhu awal direkodkan.
Leburan naftalena dibiarkan menyejuk.
Bacaan suhu direkodkan setiap 30 saat.
Rajah di bawah menunjukkan bacaan termometer yang direkodkan pada sela masa 30 saat.

Figure
Rajah
(a) | Record the temperatures in the spaces provided in Figure above.
Catatkan suhu pada ruang yang disediakan dalam Rajah di atas.[3 marks]
[3 markah] | (b) | On the graph paper below, draw the graph of temperature against time for the cooling of Use naphthalene. Pada kertas graf di bawah, lukiskan graf suhu melawan masa bagi penyejukan naftalena.

Graph of the cooling of naphthalene/Graf penyejukan naftalena [3 marks]
[3 markah] | (c) | (i) | Use the graph in (b), to determine the freezing point of naphthalene.
Show on the graph how you determine this freezing point.
Gunakan graf di (b), untuk menentukan takat beku naftalena.
Tunjukkan pada graf bagaimana anda menentukan takat beku ini.[3 marks]
[3 markah] | (ii) | How does the graph in (b) show the freezing point of naphthalene?
Bagaimanakah graf di (b) dapat menunjukkan takat beku naftalena?

__________________________________________________________________________________

__________________________________________________________________________________

__________________________________________________________________________________[3 marks]
[3 markah] |

| (d) | The temperature of naphthalene did not change from the 90th second until the 150th second

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