Sci- testing, mixing and separating

Question 1

What is a compound (give examples)

Answer 1

A compound is any substance that has 2 or more elements chemically joined together in a fixed ratio.
Eg. Water H20, salt NaCl, sugar C12H22011

Question 2

what is a mixture

Answer 2

a matreial made up of 2 or more substances that are physically combined. Individual substances retain their own proporties
eg air

Question 3

What is a chemical formula

Answer 3

A chemical formula is an expression that shows the elements in a compound and the relative proportions of those elements.
eg water

Question 4

Dissolve

Answer 4

The process of mixing the solute with the solvent to get a clear solution.

Question 5

Dilute

Answer 5

few particles of a solute are present in a given volume of solvent

Question 6

concentrated

Answer 6

lots of particles of a solute are present in a given volume of solvent

Question 7

saturated

Answer 7

no more solute can dissolve in the solvent

Question 8

solute

Answer 8

the substance that you dissolve

Question 9

solvent

Answer 9

the liquid that you dissolve substances in

Question 10

solution

Answer 10

the mixture formed when you dissolve a solute into a solvent

Question 11

Soluble

Answer 11

able to be dissolved in a solvent

Question 12

insoluble

Answer 12

unable to be dissolved in a solvent

Question 13

what is CO2

Answer 13

carbon dioxide

Question 14

what is MgCI2

Answer 14

Magnesium chloride

Question 15

what is CaCI2

Answer 15

calcium chloride

Question 16

2 proporties of carbon dioxide gas

Answer 16

odorless and colourless

Question 17

what is the word equation for producing hydrogen gas in the lab + the name of the test for it

Answer 17

hydrochloric acid+magnesium—–> magnesium chloride +hydrogen gas
pop test

Question 18

word equation for carbon dioxide +test for it

Answer 18

calcium carbonate+nitric acid—–> calcium nitrate+carbon dioxide+water

lime water test

Question 19

word equation for oxygen + test for it

Answer 19

hydrogen peroxide—- manganese dioxide–> water
glowing splint test

Question 20

how many times should you repeat a test to calculate a fair average

Answer 20

3

Question 21

what is filtration

Answer 21

filtration seperates solble particles from insoluble particles in a solvent. If you have a mixture of two solids you can add water to dissolve one, filter off the insoluble one and then evaporate the water from the dissolved solid to recrystallize the soluble solvent.

Question 22

what is evaporation

Answer 22

To remove a solute that is dissolved in a solvent you can use evaporation. The solution is poured into an evaporating dish and heated. The solvent forms a gas and evaporates, leaving the solute as a solid in the dish.

Question 23

what is distillation

Answer 23

if you want to collect the solvent as well as the solid or if you have two different liquids, then you should use distillation. It separates substances on the basis of their boiling points

Question 24

LOOK OVER SEPERATING THING

Answer 24

DO IT

Question 25

Positive test for hydrogen

Answer 25

You will hear a loud squeaky pop.

Question 26

positive test for carbon dioxide

Answer 26

liquid turns a milky colour

Question 27

positive test for oxygen

Answer 27

the splint relights, often many times

Question 28

what is the correct symbol for sodium hydroxide

Answer 28

S(H)2

Question 29

what is a mixture with excess solute is called

Answer 29

saturated solution

Question 30

what seperates liquids

Answer 30

chromotography