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

The information provided indicates a process involving the heating of a mixture and the observation of phase changes.

1.At 100 °C, the water begins to boil. This suggests that the unknown substance is likely dissolved or mixed with water, and the boiling point of water is reached.

2.At 200 °C, everything in the container becomes a liquid. This suggests that the unknown substance has a melting point of 200 °C.

Given this information, we can eliminate table salt (NaCl) and table sugar (sucrose) from consideration because their melting points are much lower than 200 °C. The melting point of table salt is around 801 °C, and the melting point of table sugar is around 186 °C.

Now, between lead and aluminum, we need to consider their melting points:

The melting point of lead is around 327 °C.

The melting point of aluminum is around 660 °C.

Since the observed melting point is 200 °C, it is lower than both lead and aluminum. Therefore, none of the options (A) lead, (B) aluminum, (C) table salt, and (D) table sugar perfectly match the given information.