Quantitative Chemistry- Paper 1 Flashcards

1
Q

Why might a % yield of a reaction not be 100%?

copper oxide

A

Some solution left behind when mixture was filtered

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2
Q

What’s the value of Avogadro constant?

A

6.02 x 10^23

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3
Q

What is Avogadro’s constant used for?

A

The number of particles in a mole.

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4
Q

What does the conservation of mass mean?

A

That during a reaction no atoms are created or destroyed so mass of reactants=mass of products

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5
Q

What is meant by the term limiting reactant?

A

When a reactant gets used up in a reaction before the rest and therefore stops the reaction.

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6
Q

What volume does one mole of any gas occupy at room temperature and pressure?

A

24dm^3

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7
Q

State the values of room temperature and pressure

A

20 degrees C

1 atm.

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8
Q

How do you calculate the atom economy of a reaction?

A

Mr of desired products/Mr of all reactants x 100

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9
Q

How do you calculate the % yield

A

mass of product made/ maximum mass of product x 100

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10
Q

Why do people want high % yields?

A

To reduce waste and extra cost.

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11
Q

Give 3 reasons why % yield is always less than 100%?

A

Not all reactants react to make a product
There may be side reactions
You lose some product when you separate it from the reaction mixture

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