Chemistry OCR Gateway GCSE C5.1

What is yield?

The yield of a product is the amount mass of it produced in a reaction

What is theoretical yield?

the maximum mass it is possible to make from a given mass of reactants

Law of Conservation of Mass

mass cannot be created or destroyed, only transferred

What is actual yield

the mass of the product that is actually made in a reaction, usually less than theoretical yield

What is percentage yield

the percentage of the theoretical yield that is the actual yield

Percentage yield formula

percentage yield = actual yield/theoretical yield x 100

Reasons why percentage yield may be less than 100%?

-Reactants may react in a different way than expected

-Reaction may not go to completion, not all reactants may react

-raw materials may not be pure

some of the product may be lost when separated from the mixture

What is atom economy?

A measure of how many reactant atoms form a desired product

atom economy formula

Atom economy = Mr of Desired Product / Mr of All Products x 100

What is Avogadro's constant?

6.02 x 10^23 /mol, is equal to the number of atoms in 1 mole.

Formula triangle for mass moles Mr

Convert cm^3 into dm^3

cm^3/1000 = dm^3

To calculate concentration

volume of 1 mole of gas at RTP

24dm^3

formula triangle for moles of gas