double science memorizable stuff

Question 1

what is the definition of a solvent

Answer 1

the liquid in which a solute dissolves

Question 2

what is the definition of a solute

Answer 2

the substance which dissolves in liquid to form a solution

Question 3

what is the definition of a solution

Answer 3

the mixture formed when a solute is dissolved in a solvent

Question 4

what is the definition of a saturated solution

Answer 4

a solution with the maximum concentration of solute dissolved in the solvent

Question 5

what is the definition of an element

Answer 5

a substance made of atoms that all contain the same number of protons and cannot be split into anything simpler

Question 6

what is the definition of a compound

Answer 6

A pure substance made up of two or more elements chemically combined

Question 7

what is the definition of a mixture

Answer 7

a combination of two or more substances that aren’t chemically combined

Question 8

what is the definition of a pure substance

Answer 8

a substance that has a fixed melting and boiling point

Question 9

what is the definition of an atom

Answer 9

the smallest particle of an element that contains electrons surrounding a nucleus that contains protons and neutrons

Question 10

what is the definition of a molecule

Answer 10

A group of two or more atoms chemically combined to form an idetifiable unit which retains the properties and composition of the substance

Question 11

reaction of lithium with water

Answer 11

• relatively slow reaction
• fizzing
• lithium moves on the surface of the water

Question 12

reaction of sodium with water

Answer 12

• more vigorous fizzing
• moves rapidly on the surface of the water
• dissolves quickly

Question 13

reaction of potassium with water

Answer 13

• reacts more vigorously than sodium
• burns with a lilac flame
• moves very rapidly on the surface
• dissolves very quickly

Question 14

Colour and property of (halogen) fluorine

Answer 14

yellow gas

Question 15

Colour and property of (halogen) chlorine

Answer 15

gas - pale yellow green gas

Question 16

Colour and property of (halogen) bromine

Answer 16

liquid - red brown liquid

Question 17

Colour and property of (halogen) iodine

Answer 17

solid - grey solid

Question 18

reactivity series order

Answer 18

please send lions, cats, monkeys and cute zebras into hot countries signed gordon.

potassium,sodium,lithium,calcium,magnesium,aluminium,carbon,zinc,iron,hydrogen,copper,silver,gold

Question 19

colour of litmus

Answer 19

In acid:
red

in alkali:
blue

Question 20

colour of phenolpthalein

Answer 20

In acid:
colorless

In alkali:
pink

Question 21

colour of methyl orange

Answer 21

In acid:
red

In alkali:
yellow

Question 22

prepare a soluble salt

Answer 22

1) add excess insoluble base to the acid
2) filter to remove unreacted base
3) heat the solution so that water evaporates and crystals of the salt remain

Question 23

prepare a sample of pure, dry hydrated copper sulfate crystals starting from copper oxide

Answer 23

1) heat acid until warm, then add metal base stirring constantly until it stops dissapearing
2) filter mixture to remove excess base, transfer solution to evaporating basin
3) evaporate water from solution using a bunsen burner until crystals appear
4) remove evaporating basin from heat and allow filtrate to dry and crystallize

Question 24

Test for ammonia

Answer 24

• hold litmus paper near the mouth of the test tube
• damp red litmus paper turns blue

Question 25

Test for carbon dioxide

Answer 25

-bubbling gas through an aqeous solution of limewater - if the gas is co2 limewater turns cloudy

Question 26

Test for chlorine gas

Answer 26

- litmus paper - if chlorine gas is present, damp blue litmus paper will turn red and the be bleached white

Question 27

Test for hydrogen gas

Answer 27

- hold a burning splint at the open end of a test tube of gas - if the gas is hydrogen, it burns with a loud squeaky pop

Question 28

test for oxygen

Answer 28

- consists of placing a glowing splint inside a test tube of gas - if the gas is oxygen, the splint will relight

Question 29

test for lithium

Answer 29

- flame test - red

Question 30

test for sodium

Answer 30

- flame test - yellow

Question 31

test for potassium

Answer 31

- flame test - lilac

Question 32

test for calcium

Answer 32

- flame test - orange-red

Question 33

test for copper

Answer 33

-flame test - blue-green

Question 34

Test for (metal ion + sodium hydroxide) copper

Answer 34

- aqeuous solution - light blue precipitate formed

Question 35

Test for (metal ion + sodium hydroxide) iron 2+

Answer 35

- aqeuous solution - green precipitate formed

Question 36

Test for (metal ion + sodium hydroxide) iron 3+

Answer 36

- aqeuous solution - brown precipitate formed

Question 37

test for carbonate ions

Answer 37

- add dilute acid - bubble the gas release through limewater - limewater turns cloudy if the carbonate ion is present

Question 38

test for halide ions

Answer 38

- acidify the sample with nitric acid - add silver nitrate solution - a silver halide precipitate forms if a halide ion is present chloride ion - white precipitate of silver chloride bromide ions - cream precipitate of silver bromide Iodine ions - yellow precipitate of silver iodide

Question 39

test for sulfate ions

Answer 39

- acidify the sample with dilute hcl - add a few drops of barium chloride solution - a white precipitate of barium sulfate is formed, if the sulfate ion is present

Question 40

chemical test for water

Answer 40

- anhydrous copper sulfate turns from white to blue on the addition of water

Question 41

homologous series

Answer 41

a series or family of organic compounds that have similar features and chemical properties due to them having the same functional group

Question 42

functional group

Answer 42

a group of atoms bonded in a specific arrangement that influences the properties of the homologus series

Question 43

isomers

Answer 43

compounds that have the same molecular formula but diffeerent displayed formula

Question 44

process of fractional distillation in crude oil

Answer 44

1) crude oil is heated and vaporised 2) the vapour of hydrocarbons enter the column which has a temperature gradient 3) the vapours of hydrocarbons with high boiling points condense at the bottom of the column 4) the vapours of hydrocarbons with lower boiling points rise up the column and condense at the top

Question 45

cracking conditions

Answer 45

- 600-700 degrees - catalyst - silica or aluminia

Question 46

bromine water test

Answer 46

- when bromine is added to an alkane, it will remain as am orange solution - when added to alkene bromine becomes colorless