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Flashcards in Equations Deck (13):

What name is given to the sum of the relative atomic masses of the atoms in a molecule?

The relative formula mass


What is the definition of a mole?

The mole is the relative formula mass of the substance in grams


What is the mass of one mole of oxygen gas?

One mole of O2 weighs 16x2=32g


Which equation is the empirical formula?

The one with the ratios


Which equation is when you calculate the mass?

Where you divide and then times


What is the equation for percentage yield?

Actual yield percentage yield=____________x100

Predicted yield


What does a 0% yield mean?

A 0% yield means that no reactants were converted into products


What are the three reasons why yields can't be 100%?

1) The reaction is reversible

2) filtration

3) unexpected reactions


The reaction is reversible therefore the yield can't be 100%. Why is this?

This means that reactants will never be completely converted to products because the reaction goes both ways. This will mean a lower yield


Why does filtration mean that yields can't be 100%?

When you filter a liquid to remove salvage parts you nearly always lose a bit of a liquid or a bit of solid so some of the product may be lost when its separated from the reaction mixture


Why does unexpected reactions mean that yields can't be 100%?

Things don't always go exactly to plan sometimes there can be other unexpected reaction is happening with use of the reactants this means that there is not what you reactant to make the product you want


Why might a reaction with a low percentage yield be bad for sustainable development?

Because a low product yield means that resources are wasted rather than being saved for future generations


What name is given to the average mass of isotopes of an element?

The relative atomic mass