CHEMISTRY MIDTERMS

Question 1

WHAT IS A PURE SUBSTANCE?

Answer 1

A PURE SUBSTANCE IS MADE UP OF ONLY ONE SUBSTANCE AND IS NOT MIXED WITH ANY OTHER SUBSTANCES.

Question 2

NAME 3 EXAMPLES OF PURE SUBSTANCES.

Answer 2

Mg,NaCl,H20, a crystal.

Question 3

WHAT DOES PURE SUGAR CONTAIN?

Answer 3

PURE SUGAR CONTAINS SUGAR CRYSTALS ONLY.

Question 4

IF A SUBSTANCE IS IMPURE,WHAT DOES THIS MEAN?

Answer 4

THIS MEANS THAT THE SUBSTANCE IS MADE UP OF MORE THAN ONE KIND OF SUBSTANCE.

Question 5

GIVE AN EXAMPLE OF AN IMPURE SUBSTANCE.

Answer 5

COPPER ORE.

Question 6

WHAT IS A MIXTURE?

Answer 6

A MIXTURE CONSISTS OF TWO OR MORE SUBSTANCES THAT ARE COMBINED PHYSICALLY,NOT CHEMICALLY.

Question 7

GIVE AN EXAMPLE OF A MIXTURE.

Answer 7

STONES IN SAND.

Question 8

WHAT IS AN ALLOY?

Answer 8

ALLOYS ARE MIXTURES OF TWO OR MORE METALS.

Question 9

NAME 3 EXAMPLES OF MIXTURES?

Answer 9

PDR (PETROLEUM,DETERGENT AND RUBY).

Question 10

WHAT ARE THE TWO TYPES OF MIXTURES?

Answer 10

HOMOGENEOUS AND HETEROGENEOUS.

Question 11

WHAT IS A HOMOGENEOUS MIXTURE?

Answer 11

A MIXTURE IN WHICH THE COMPOSITION IS UNIFORMED THROUGHOUT THE MIXTURE.

Question 12

WHAT IS A HETEROGENEOUS MIXTURE?

Answer 12

A MIXTURE IN WHICH THE COMPOSITION IS NOT UNIFORMED THROUGHOUT THE MIXTURE.

Question 13

IS A SOLUTION A HOMOGENEOUS MIXTURE OR A HETEROGENEOUS MIXTURE?

Answer 13

A HOMOGENEOUS MIXTURE.

Question 14

WHAT IS A SOLUTION MADE UP OF?

Answer 14

A SOLUTE AND A SOLVENT.

Question 15

EXPLAIN SOLUTE AND SOLVENT IN YOUR OWN WORDS.

Answer 15

STATE THE ANSWER IN YOUR OWN WORDS.

Question 16

GIVE AN EXAMPLE OF A SOLUTION AND SAY WHICH ONE IS A SOLUTE AND WHICH ONE IS A SOLVENT.

Answer 16

SALT WATER WHERE THE SALT IS THE SOLUTE AND THE WATER IS THE SOLVENT.

Question 17

WHAT DO YOU CALL A SOLVENT THAT IS WATER?

Answer 17

AN AQUEOUS SOLUTION.

Question 18

WHAT DO YOU CALL A SOLVENT THAT IS NOT WATER?

Answer 18

NON-AQUEOUS SOLUTION.

Question 19

WHAT IS A SATURATED SOLUTION?

Answer 19

A SATURATED SOLUTION IS WHEN THE MAXIMUM AMOUNT OF SOLUTE CAN DISSOLVE IN A GIVEN AMOUNT OF SOLVENT AT A FIXED TEMPERATURE.

Question 20

HOW IS SOLUBILITY MEASURED?

Answer 20

THE MASS OF THE SOLUTE DISSOLVED IN 100G OF SOLVENT.

Question 21

WHAT ARE THE THREE FACTORS AFFECTING SOLUBILITY?

Answer 21

TEMPERATURE,PRESSURE AND THE NATURE OF THE SOLUTE AND SOLVENT.

Question 22

IS A COLLOID A HOMO OR HETEROGENEOUS MIXTURE?

Answer 22

A HETEROGENEOUS MIXTURE.

Question 23

GIVE 2 EXAMPLES OF COLLOIDS.

Answer 23

MILK AND BLOOD.

Question 24

WHAT IS AN EMULSION AND GIVE AND EXAMPLE.

Answer 24

AN EMULSION IS A TYPE OF COLLOID IN WHICH TINY LIQUID PARTICLES IS DISPERSED IN ANOTHER LIQUID.AN EXAMPLE IS MILK.

Question 25

WHAT IS THE TYNDALL EFFECT?

Answer 25

THIS OCCURS WHEN THE PARTICLES ARE BIG ENOUGH TO DISPERSE LIGHT.

Question 26

GIVE AN EXAMPLE OF A SUSPENSION.

Answer 26

A SANDSTORM.

Question 27

WHAT IS A SUSPENSION?

Answer 27

A SUSPENSION IS A HETEROGENEOUS MIXTURE IN WHICH LIQUID OR SOLID PARTICLES ARE SUSPENDED IN A LIQUID OR GAS MEDIUM.

Question 28

GIVE 3 EXAMPLES OF SUSPENSIONS.

Answer 28

SANDSTORMS,MUDDY WATER AND CHALK POWER SUSPENDED IN WATER.