Question 2 Which statement describes a change of matter that I DIFFERENT from the others?

A

Peroxide breaking down into water and oxygen

B

Bubbles forming when a pot of water is heated

A pair of jeans soaked in water drying after hanging outside

D

A block of ice decreating in size due to a change in temperature

A.  Peroxide breaking down into water and oxygen

Explanation:

Generally when it comes to changes, there are physical and chemical changes. In physical changes, there are no new substances been formed, however in chemical change new substances are formed.

A.  Peroxide breaking down into water and oxygen

This is a chemical change.

B . Bubbles forming when a pot of water is heated

This is a physical change

C. A pair of jeans soaked in water drying after hanging outside

This is a physical change

D . A block of ice decreasing in size due to a change in temperature

This is a physical change.

Only option A is different from the rest,hence this is the answer.

b. examine and describe cells

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.