CH-1398
Purity and melting point
Chemistry · Secondary 4 · Medium · Purity and melting point
A student tests the purity of a sample of naphthalene by measuring its melting point. Pure naphthalene melts sharply at 80 °C.
The sample starts melting at 76 °C and finishes melting at 79 °C.
What does this show about the sample?
The sample starts melting at 76 °C and finishes melting at 79 °C.
What does this show about the sample?
- It is impure because it melts over a range below 80 °C
- It is pure because it is a solid at room temperature
- It is pure because it melts completely by 79 °C
- It is impure because its melting point is higher than 80 °C
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