Download - CHEMICALS AND CHEMICAL CHANGE
CHEMICALS AND CHEMICAL CHANGE
Chapter 5.1 BLM 5.1a, 5.1b
Chemicals and chemical Change
CHEMISTRY – is the study of matter, its changes and its properties
MATTER – is anything that has mass and takes up space
ATOM – the smallest particle of matter
PHYSICAL CHANGE – a change in a substance which does not produce a new substance.• Easy to reverse• Ex. Melting ice
CHEMICAL CHANGE – a change in a substance which does produce a new substance.• Difficult to reverse• Ex. Match burning
Classification of matter
Classification of matter
Classify each substance as 1) A pure substance or a mixture, and 2) An element, molecule, heterogeneous mixture or homogeneous:a) Glass of milkb) Spoonful of sugar
c) A bar of goldd) Orange juice with pulp
Science 10 – Nov. 3rd
Classify each reaction as a physical or chemical reaction:a) Butter meltingb) Cheese molding
c) Breaking a chocolate bar in halfd) Burning toast
Science 10 – Nov. 3rd
Classify each substance as 1) A pure substance or a mixture, and 2) An element, molecule, heterogeneous mixture or homogeneous:a) Glass of milkb) Spoonful of sugar
c) A bar of goldd) Orange juice with pulp
Physical Reaction vs. Chemical Reaction
Physical reactions are easy to reverse while chemical reactions are not. • Ex “When ice melts is it easy to reverse
that reaction? Burning a match?”
Physical Trait vs. Chemical Trait Physical traits are either simple
observations or things having to do with physical reactions.• Color, smell, size, mass, boiling point,
melting point. Chemical traits have to do with
chemical reactions.• Will it catch on fire?• Ability to react with other chemicals.• Stable or unstable.
Science 10 – Nov. 1st
1) Classify each as 1) Pure substance or mixture, then 2) Element, compound, homogeneous mixture or heterogeneous mixture.
a) Sugarb) Copper wirec) Aird) Orange juice w/ pulpe) Orange juice w/o pulp
Science 10 – Nov. 1st
2) Classify each as a physical change or a chemical change:
a) Food rottingb) Breaking a carrot in half c) Water boilingd) Making toaste) Dissolving salt into water
Science 10 – Nov. 1st
3) Classify each as a physical trait or chemical trait:
a) Water freezes at 0oCb) Ethanol is a clear liquidc) Gold does not react with acidd) Aluminum is a malleable metal e) Mercury metal is a liquid at room
temperature
HOMEWORK QUESTIONS Page 175 QUESTIONS: #1,2,4,5,6,7 Explain in your own words the
difference between element, atom, molecule and compound.
Work on project
SOLUTIONS TO HOMEWORK QUESTIONS
Q1 – classify each of the following as a pure substance or a mixture
A) soapy water MIXTURE
B) hydrogen gas PURE SUBSTANCE
C) sodium chloride PURE SUBSTANCE
QUESTION 2Classify each of the following as an element
or a compound.A) hydrogen
ELEMENTB) potassium carbonate
COMPOUNDC) water
COMPOUNDD) Mg
ELEMENT
QUESTION 4
Classify each of the following as a physical property or a chemical property.
A) Gasoline is a clear pink solutionPHYSICAL PROPERTY
B) Gasoline burns in airCHEMICAL PROPERTY
C) Water boils at 1000C. PHYSICAL PROPERTY
D) electric current can split water into hydrogen and oxygen gases CHEMICAL PROPERTY
QUESTION 5When aluminum metal is added to
hydrobromic acid, hydrogen gas and an aluminum bromide solution are formed.
A) What kind of change has occurred?
A chemical change has occurred because new substances were made.
QUESTION 5When aluminum metal is added to
hydrobromic acid, hydrogen gas and an aluminum bromide solution are formed
B) Which substances are the reactants and which are the products?
Reactants – Aluminum and AcidProducts – Hydrogen + Aluminum
Bromide
QUESTION 6Describe the chemical tests that can
be used to identify the following gases.
A) hydrogen a flaming wooden splint causes a “pop”
B) Oxygen a glowing wooden splint relights (bursts into flame)
QUESTION 6C) Carbon Dioxide
A burning wooden splint extinguishes, OR when the gas is bubbled through limewater, the limewater changes from a clear, colourless solution to a cloudy white liquid (a precipitate is formed)
QUESTION 6d) Water Vapour
Changes the colour of cobalt chloride test paper from blue to pink
QUESTION 7When sodium carbonate is added to
water, the sodium carbonate dissolves. When hydrochloric acid is added to the solution, the solution fizzes. What kinds of changes have occurred?
QUESTION 7 - ANSWERWhen sodium carbonate dissolves in
water it is a physical changeA chemical change happens when gas
is formed after hydrochloric acid is added ( fizz / Bubbles )