Is matter around us pure? Flashcards
WHAT IS THE SCIENTEFIC DEFINITION OF A PURE SUBSTANCE?
1) A PURE SUBSTANCE CONSISNTS OF A SINGLE TYPE OF PARTICLE AND ALL IT’S CONSTITUENT PARTICALS ARE CHEMICALLY IDENTICAL.
2) HAS A FIXED COMPOSITION
3) EXAMPLE: SUGAR, SODIUM CHLORIDE
WHAT IS A MIXTURE
1 )A MIXTURE IS MADE UP OF TWO OR MORE PURE SUBSTANCES.
2) IT’S COMPOSITION VARIES
3) EXAMPLE: SOIL AND SOFT DRINKS
CAN THE COMPONETS OF MIXTURE BE SEPARATED?
YES, THE COMPONETS OF MIXTURE CAN BE SEPARATED THROUGH PHYSICAL PROCESSES SUCH AS EVAPORATION, FILTERATION ETC
CAN A PURE SUBSTANCE BE SEPARATED WITH PHYSICAL PROCESSES
NO A PURE SUBSTANCE CANNOT BE SEPARATED WITH PHYSICAL PROCESSES. IT CAN ONLY BE SEPARATED WITH CHEMICAL PROCESSES. FOR EXAMPLE: ELECTROLYSIS
WHAT IS A HOMOGENEOUS MIXTURE?
A MIXTURE WHICH HAS UNIFORM COMPOSITION THROUGHOUT IS KNOWN AS HOMOGENEOUS MIXTURES
GIVE TWO EXAMPLES OF HOMOGENOUS MIXTURES
EXAMPLE: SALT DISSOLVED IN WATER AND SUGAR DISSOLVED IN WATER
CAN THE COMPOSITION OF A HOMOGENEOUS MIXTURE VARY?
YES THE AMOUNT OF SOLUTE MAY VARY BUT THE MIXTURE REMAINS UNIFORM
WHAT IS A HETROGENEOUS MIXTURE?
A MIXTURE WITH NON UNIFORM COMPOSITION AND PHYSICALLY VISIBLE DISTINCT PARTS IS KNOWN AS HETROGENEOUS MIXTURES
GIVE TWO EXAMPLES OF A HETROGENOUS MIXTURE
EXAMPLES: OIL AND WATER AND SALT AND SULPHUR
WHAT IS A SOLUTION?
A SOLUTION IS A HOMOGENEOUS MIXTURE OF TWO OR MORE SUBSTANCES
GIVE TWO EXAMPLES OF SOLUTIONS
LEMONADE AND SODA WATER
WHAT ARE THE COMPONENTS OF A SOLUTION?
1) SOLVENT: SUBSTANCE WHICH DISSOLVES THE SOLUTE (EXAMPLE WATER IN LEMONADE)
2)SOLUTE: THE SUBSTANCE WHICH GETS DISSOLVED (EXAMPLE LEMON JUICE IN LEMONADE)
WHAT ARE THE PROPERTIES OF A SOULTION
1) HOMOGENOUS MIXTURE ( PARTICLES ARE UNIFORMLY SPEARD)
2) PARTICLE SIZE ( PARTICLES ARE SMALLER THAN 1 NANOMETER AND CANNOT BE SEEN WITH NAKED EYES)
3) PARTICLES ARE VERY SMALL HENCE THEY DON’T SCATTER LIGHT
4) CANNOT BE SEPARATED THROUGH PHYSICAL PROCESSES SUCH AS FILTERATION
5) STABILITY : PARTICLES DON’T SETTLE AT THE BOTTOM WHEN LEFT UNDISTURBED , BASICALLY THE PARTICLE IS STABLE
PROPERTIES OF A MIXTURE
1) NO NEW SUBSTANCE IS FORMED
2) CAN BE SEPARATED THROUGH PHYSICAL CHANGE
3) CAN EITHER BE HOMOGENEOUS OR HETROGENOUS
4) CAN EXIST IN ALL THREE STATES OF MATTER
5) COMPOSITION VARIES
6) NO FIXED PROPORTION
7) MIXTURES RETAIN THEIR INDIVIDUAL PHYSICAL PROPERTIES
PROPERTIES OF SUSPENTION
1) IT IS A HETROGENEOUS MIXTURE, MEANING IT HAS A NON UNIFORM CONSTITUTION
2) PARTICLES ARE VISIBLE TO THE NAKED EYES
3) IT HAS PHYSICALLY DISTINCT PART
4) IT SCATTERS LIGHT, MEANING THE LIGHT PATH IS VISIBLE
5)CAN BE SEPEPARETED WITH PHYSICAL PROCESSES SUCH AS FILTERATION
6) IF THE SOLUTION IS LEFT UNDISTURBED, PARTICLES WILL SETTLE DOWN , INDICATING THE SOLUTION IS UNSTABLE
can a solution be present in all 3 states of matter, if yes give examples.
yes a solution can be present in all 3 states of matter. examples
1) gaseous- air
2)solid- alloy ( brass = zinc +copper)
3)liquid - sugar solution, salt solution , lemonade
what are alloys
alloys are a mixture of two or more metal or non mental
why is an alloy considered a mixture when it can’t be separated through physical means?
alloys are considered a mixture because
1) no new product is formed
2) the mixture still has the property of it’s consecutive particles
3)it has a variable composition
why is the colloidal solution considered a heterogeneous mixture if it is uniformly spread throughout and no distinct particles are visible?
because it scatters light, meaning the path of light is visible when it passes through the solution
what is Tyndall effect
the phenomenon where scattering of light takes place through the particles in a suspension or colloidal solution is known as Tyndall effect
where is the Tyndall effect seen
1)sunlight entering a dark room
2) milk
3)fog
what are the properties of a Collidal solution
1) particles cannot be seen
2) it is quite stable
3) it does scatter light
4)particles are uniformly spread
what are the two divisions of pure substance
elements & minerals
what are elements
element is a form of matter that cannot be broken down into simpler substances by chemical reactions.
who was the first scientist to use the term elements?
Robert Boyle (1661)
after which scientist is the Tyndall effect named after
John Tyndall
who defined the term element
Antoine Laurent Lavoisier
properties of metals
1) they has luster
2) they are ductile
3) they are malleable
4) they are sonorous
5) they are good conductors of heat
6) they have a silvery-grey or golden-yellowish color
examples of metal
gold, silver etc
example of metal which are liquid at room temperature
mercury, bromine
example of metals which are liquid slightly above room temperature
gallium, cesium (303K)
properties of non metals
1) they have various color
2) bad conductor of heat
3) they are not ductile, malleable, sonorous
example of non metal
nitrogen, oxygen, carbon
what are metalloids
metalloids are elements which have properties of both metals and non metals
example of metalloids
boron, silicon and germanium
how many elements are gaseous at room temperature
11
what is a compound
a compound is a substance composed of two or more elements chemically combined in a fixed proportion
properties of a compound
1) fixed composition
2) doesnt have properties of the constituent particles
3)can only be separated through chemical processes
examples of compound
water, carbon dioxide
depending upon the amount of solute present in a given solution the solution can be_________, __________ or___________.
1) dilute
2) concentrated
3) saturated
meaning of a dilute solution
a solution which has move amount of solvent than solute
meaning of a concentrated solution
a solution which has large amount of solute compared to solvent
meaning of saturated solution
when no more solute can be dissolved in the solution in a given temperature the solution is said to be saturated
meaning of unsaturated solution
an unsaturated solution is a solution in which more solute can be dissolved at a given temperature, in other words the solution hasn’t reached it’s saturation level
define solubility
the amount of solute present in the saturated solution at a given temperature is called it’s solubility
properties of physical change
1) no new substance is formed
2) can be reversed
3) change of state of matter
properties of chemical change
1) new substance is formed
2) cannot be reversed
3) boiling, digestion of food, rusting of iron
