Question

PARAGRAPH :=
Make two paper cups by folding sheets of paper. Half --fill one of the cups with
water. Fix two burning candles on a table. Heat the two cups above the candle
flames.
Now answer the following questions:
A. Which cup starts burning?
B. Why does the cup with water in it not start burning?
C. Does the water in it become hot?
D. Define Ignition Temperature.
E. What is combustion?​

Answer 1

Answer:

A thin paper cup filled with water does not catch fire when placed over a flame because the paper cup does not become appreciably hotter than the water it contain.

When paper cup is heated containing water, water absorbs the heat coming from the burning source and thus prevents the paper from reaching its ignition point. Hence it does not burn. Water in the cup becomes hot instead. This is due to absorption of heat by water