Consider the statement:
“the temperature of the land is an important factor for the ripening of oranges, because it affects the evaporation of water and the humidity of the surrounding air.” how many of these factors, temperature
ripening evaporation humidity are chemical properties or changes?
a. 1

b. 3

c. 2

d. 4

e. none

  A. 1

Explanation:

A physical change is defined as a change in physical properties of a matter such as shape , size and its state ( Solid , liquid or gas ).

This process is a reversible process.

On the other hand a chemical change is defined as a change in chemical properties of a matter such that its composition gets changed . This process is irreversible.

Given Factors : temperature  , ripening , evaporation , humidity

Here,

Physical changes are : temperature  , evaporation , humidity because they are reversible, they do not form a new substance.

But ripening of oranges is an irreversible process because its a chemical change in it which makes fruit more sweeter and softer.

Hence, there is only 1 factor which is a chemical change.

the enthalpy of formation of water is given as -285.8kj/mol, which states that the enthalpy of formation is negative.

negative enthalpy of formation indicates that the heat is released during the reaction process. the heat is released from reaction to the surroundings the enthalpy is expressed with a negative sign with the energy given out in the reaction process.

the formation of water takes place by giving out heat which is -285.8 kj/mol.