Which of the following will result in a chemical change A melting ice to obtain water B evaporating alcohol into vapor C drying wood in a shed D burning coal in a furnace?

Answer 1

The answer is D !

(a) melting ice to obtain water - is changing waterfrom its solid form to liquid by heat.

(b) evaporating alcohol into vapour - is changing alcohol from liquid to a gas.

(c) drying wood in a shed - is simply allowing Amy moisture present in the wood to evaporate. In all three of these cases the original material remains chemically unchanged.

in (d) burning coal in a furnace - the cellular structure of the wood is broken down by heat - the individual wood cells are destroyed, turning it from cellulose to carbon.

Answer 2

D) burning coal in a furnace leads to a chemical change because a form of energy alters the chemical bonds of the coal resulting in a change in the coal molecules

WRONG

A) there is no chemical change to the water molecules, they only altered their physical form (solid to liquid to gaseous)

B)there is no chemical change to the alcohol molecules, they only altered their physical form (liquid to gaseous)

C) there is no chemical change to the water or wood molecules, the water molecules are only altering their physical form (Liquid to gaseous)

Answer 3

B is a chemical change. This is because you are adding energy to the system, and causing an irreversible change in the wood.

A and C are both physical changes, and can be reversed. Most physical changes include cutting, mixing, or changes in phases (solid, liquid, gas).

Answer 4

burning coal is a combustion reaction and is a chemical change.

Answer 5

Burning coal in a furnace