Chemistry- Conservation of Mass and Energy

Physical properties definition

can be determined without changing the composition

Examples of physical properties

colour, mass, density, hardness, solubility, electrical conductivity, melting/boiling point

Chemical Properties definition

determined only by changing the chemical composition, related to the chemical reactivity of the substance

Chemical properties examples

flammability, likeliness to corrode, ability to be oxidised/ reduced

Physical change defintion

a change to the physical properties of a substance, no new substances are formed

Properties of a physical change

no new substances, easily reversible, no bonds broken or made, no change in colour/pH

Chemical change definition

A change to the chemical properties of a substance, one or more new substances formed

Properties of a chemical change

new substances formed, bonds broken/made, difficult to reverse, changes in pH or colour, precipitate/gas may be formed

Law of conservation of mass

the total mass of the products in a reaction must be equal to the total mass of the reactants

Masses in model of law of conservation of mass

36.458 HCl + 39.998 NaOH = 54.44 NaCl + 18.016 H2O

Law of conservation of energy

energy can be neither created nor destroyed, but simply changes from one form to another

Example of law of conservation of energy

Ice cube melting, heat energy absorbed and used by particles as kinetic energy