C4:Chemical calculations Flashcards
What atom is relative atomic mass compared to?
Carbon
what is Ar (little r)
relative atomic mass
How to find Mr
add all relative atomic masses in the formula (times by little numbers)
triangle for solid
mass
moles x Mr
triangle for liquid
moles
conc x vol
triangle for gas
vol
mol x 24
percentage yield
(actual mass of product/maximum theoretical mass of product)X100
What are the factors affecting percentage yield.
-reaction may be reversible and re-form reactants again
-unwanted products
-human error (left in apparatus)
-lost during separating
-may not be pure.
What is atom economy?
a measure of the extent to which the atoms in the reactants end up in the desired products.
Where do products not in the atom economy go?
Landfill (environmental issues)
how to calculate atom economy: (%)
(%)=(Mr of desired product/sum of Mrs of reactants)X100
what is concentration
the amount of a substance in a defined space
the point at which the acid and alkali have reacted completely is called the…
end point
what is the name of the indicator that turns from clear to pink?
phenolphthalein
