a - equations + defs

Question 1

percentage atom economy

Answer 1

mass of desired products
———————————— x 100
total mass of reactants

Question 2

percentage yield

Answer 2

actual mass
—————— x 100
theoretical mass

Question 3

concentration

Answer 3

moles
———
volume (dm3)

Question 4

isotopes

Answer 4

atoms of the same element with different number of neutrons and different masses

Question 5

relative isotopic mass

Answer 5

the mass of an atom of an isotope compared with one-twlfth of the mass of an atom of carbon-12

Question 6

relative atomic mass

Answer 6

weighted mean mass of an atom of an element compared with one-twelfth of the mass of an atom of carbon-12

Question 7

empirical formula

Answer 7

mass/Ar
/smallest no

Question 8

volume dm3 (gas)

Answer 8

= moles x 24

Question 9

water of crystallisation

Answer 9

when a compound crystallises within water and the water molecules become part of the crystal structure that forms

Question 10

water of crystallisation calculation

Answer 10

mass of solution - mass of water = mass of substance
find moles of substance and moles of water by moles = mass/Mr
water moles / substance moles = molecules of water

Question 11

percentage uncertainty

Answer 11

uncertainty
————— x 2 x 100
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