as chemistry module 2.1

Question 1

n = m/Mr

Answer 1

Moles = Mass/Mr

Question 2

N= No.p/Ac

Answer 2

No. mol = N0. particles/Avogadro’s constant

Question 3

Moles of gas

n= v /24

Answer 3

Moles of gas = Volume (cm3) / 24,000

moles of gas = volume (dm3) / 24

Question 4

n = c x v

Answer 4

moles of solution= concentration x volume mol = (mol dm3) (dm3)

Question 5

isotopes

Answer 5

atoms of the same element with different numbers of neutrons

Question 6

relative isotopic mass

Answer 6

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

Question 7

relative atomic mass

Answer 7

the weighted mean mass of an atom of an element compared to 1/12th of the mass of an atom of carbon-12

Question 8

relative molecular mass

Answer 8

the weighted mean mass of a molecule compared with 1/12th of the mass of carbon-12

Question 9

relative formula mass

Answer 9

the weighted mean mass of a formula compared with 1/12th of the mass of carbon-12

Question 10

mole

Answer 10

amount of any substance containing as many particles as there are carbon atoms in exactly 12g of carbon-12

Question 11

empirical formula

Answer 11

simplest whole number ratio of atoms of each element present in a compound

Question 12

molecular formula

Answer 12

actual number of atoms of each element in a molecule

Question 13

acids

Answer 13

proton donors

Question 14

bases

Answer 14

proton acceptors

Question 15

alkalis

Answer 15

compounds that dissolve in water to make a solution with a pH greater than 7

Question 16

salts

Answer 16

ionic compounds where the hydrogen of an acid has been replaced with another positive ion

Question 17

oxidation

Answer 17

increase in oxidation number

loss of electrons

Question 18

reduction

Answer 18

decrease in oxidation number

gain of electrons

Question 19

redox

Answer 19

one element has been oxidised, and another reduced