Question

You have been given a mixture of water and a unknown solid substance. Your teacher asks you to perform a heating process to determine what the unknown substance is. When the temperature reaches 100 °C, the water begins to boil and you are left with a white crystalline substance. When your thermometer reaches 200 °C, everything in the container becomes a liquid. What is the unknown substance?



A) lead
B) aluminum
C) table salt
D) table sugar

Answer 1

C) Table sugar: This is because sugar's melting point is the only one out of the four that has a melting point near 200°C (186°C)

Answer 2

Answer:

Table Sugar

Explanation:

The unknown substance must be table sugar.. At 200 °C, the only substances that would have melted would be water and table sugar. Everything else has a higher melting point, thus they would still be solid.