AMOUNT OF SUBSTANCE

Question 1

how to find the concentration

Answer 1

number of moles/ volume of solution

Question 2

define relative atomic mass

Answer 2

Average mass of one atom compared to 1/12th of mass of atom of carbon 12

Question 3

define relative molecular mass

Answer 3

average mass of molecule compared to 1/12th of mass of one atom of carbon 12

Question 4

how to find the number of moles

Answer 4

mass of substance/ molar mass

Question 5

what is avogadro’s constant

Answer 5

6.022x10^23

Question 6

how to find the concentration

Answer 6

number of moles/ volume of solution

Question 7

what is the ideal gas equation

Answer 7

PV=NRT

Question 8

how to find the number of particles

Answer 8

moles of substance x Avogadro’s constant

Question 9

define empirical formula

Answer 9

simplest whole number ration of atoms in each element in a compound

Question 10

how to find the empirical formula

Answer 10

work out empirical mass, divide molecular mass by the empirical mass, multiply the empirical mass by the number of units

Question 11

how to find percentage

Answer 11

change percentage to grams assuming it is 100g, calculate the moles of each element in the compound, find the empirical formula by dividing the number of moles by the lowest number present

Question 12

how to calculate the molecular formula from the empirical formula and relative molecular mass,

Answer 12

calculate the molar mass of the empirical formula, divide the molecular mass by the molar mass calculated from the empirical formula and multiply each answer by a whole number

Question 13

what does a chemical reaction indicate

Answer 13

species that are involved in the reaction and show the way they react

Question 14

define high atom economy

Answer 14

efficient conversions so reactant is maximised to form the total products