5 - amounts of substance, formulae & equations

Question 1

avogadro’s number

Answer 1

6.023×10²³

Question 2

equation with moles, mass and molar mass

Answer 2

n = mass / molar mass

Question 3

equation with moles, conc and vol

Answer 3

c = moles / volume

Question 4

% yield

Answer 4

% yield = mass of product obtained / theoretical mass of product

Question 5

atom economy

Answer 5

(mass of atoms of desired product / total Mr of all reactant atoms) x 100

Question 6

empirical formula

Answer 6

. convert % to grams
. calculate moles
. divide all results by the smallest
. find the whole number ratio

Question 7

ideal gas equation

Answer 7

pV = nRT

p = pressure
V = volume
n = moles
R = gas constant (8.31)
T = temp in kelvin

Question 8

degrees → kelvin

Answer 8

+273

Question 9

standard room temp

Answer 9

25 °C, 298 Kelvin

Question 10

standard room pressure

Answer 10

101kPa

Question 11

1 mol of gas volume

Answer 11

24dm³