Key Concepts

Question 1

What is an independent variable?

Answer 1

The variable that you change to see the effect it has on another factor

Question 2

What is a dependent variable?

Answer 2

The variable that you measure or observe

Question 3

What is a control variable?

Answer 3

A variable that must be kept constant between each run of the experiment so that no unwanted factors affect the results

Question 4

What is an extraneous variable?

Answer 4

A factor that might affect an experiment but cannot be measured or controlled. An example of an extraneous variable is atmospheric conditions

Question 5

What is an alkali?

Answer 5

A soluble base, bases are the opposite of acids, forms OH- ions when dissolved in water and has a pH of 7-14

Question 6

What is an acid?

Answer 6

A substance that produces H+ ions when dissolved in water and has a pH of 1-7

Question 7

What colour is litmus in acid?

Answer 7

Red

Question 8

What colour is litmus in alkali?

Answer 8

Blue

Question 9

What colour is phenolphthalein in acid?

Answer 9

Colourless

Question 10

What colour is phenolphthalein in alkali?

Answer 10

Pink

Question 11

What colour is universal indicator in a strong acid?

Answer 11

Red

Question 12

What colour is universal indicator in strong alkali?

Answer 12

Purple

Question 13

What colour is methyl orange in acid?

Answer 13

Red

Question 14

What colour is methyl orange in alkali?

Answer 14

Yellow

Question 15

What is the word equation for the reaction between a metal and an acid?

Answer 15

Metal + acid -> salt + hydrogen

Question 16

What is the word equation for the reaction between a metal hydroxide and an acid?

Answer 16

Metal hydroxide + acid -> salt + water

Question 17

What is the word equation for the reaction between a metal oxide and an acid?

Answer 17

Metal oxide + acid -> salt + water

Question 18

What is the word equation for the reaction between a metal carbonate and an acid?

Answer 18

Metal carbonate + acid -> salt + water + carbon dioxide

Question 19

What is a hydrated salt?

Answer 19

A salt that contains nH2O

Question 20

What is an anhydrous salt?

Answer 20

A salt that doesn’t contain water

Question 21

What is the relative mass of a proton?

Answer 21

1.0

Question 22

What is the relative mass of a neutron?

Answer 22

1.0

Question 23

What is the relative mass of an electron?

Answer 23

1/2000

Question 24

What is an isotope?

Answer 24

An atom of an element with the same number of protons but a different number of neutrons

Question 25

What is relative isotopic mass?

Answer 25

Mass of an atom of an isotope compared with 1/12th of the mass of an atom of carbon-12

Question 26

What is relative atomic mass?

Answer 26

The mean mass of all the isotopes of an element compared with 1/12 of the mass of one atom of carbon-12

Question 27

What is relative formula mass?

Answer 27

The sum of the atomic masses of all the atoms in the formula of a substance

Question 28

What is mass spectrometry?

Answer 28

Mass spectrometry is a technique used to find the abundance of different isotopes in a sample of an element, the results can be used to determine the relative atomic mass of a sample - You multiply the relative mass of the isotope by the percentage abundance of that isotope and add all of the answers together and divide by 100

Question 29

What is the charge of a nitrate ion?

Answer 29

NO3 -

Question 30

What is the charge of a carbonate ion?

Answer 30

CO3 2-

Question 31

What is the charge of a sulfate ion?

Answer 31

SO4 2-

Question 32

What is the charge of a hydroxide ion?

Answer 32

OH -

Question 33

What is the charge of a zinc ion?

Answer 33

Zn 2+

Question 34

What is the charge of an ammonium ion?

Answer 34

NH4 +

Question 35

What is the charge of a silver ion?

Answer 35

Ag +

Question 36

What is the word equation for the reaction between a metal and water?

Answer 36

Metal + water → metal hydroxide + hydrogen

Question 37

What is a catalyst?

Answer 37

A substance that alters the rate of reaction without being used up in the process