Amount of a substance Flashcards

1
Q

Empirical formula

A

The formula that represents the simplest whole number ratio of the atoms of each element in a compound

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2
Q

Molecular formula

A

the formula that gives the actual number of atoms of each element in one molecule of a compound

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3
Q

Spectator ions

A

Ions that are unchanged during a chemical reaction, that is, they do not take part in the reaction

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4
Q

The number of moles in a given volume of solution - equation

A

number of moles in solution n =

concentration c (mol dm-3) x volume V (cm3)
over 1000

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5
Q

percentage uncertainty

A

(uncertainty/vol) x 100

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6
Q

Atom economy

A

Describes the efficiency of a chemical reaction by comparing the total number of atoms in the product with the total number of atoms in the starting materials

(% atom economy =mass of desired product) x 100
over total mass of reactants

to reduce waste, find a use for the waste product

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7
Q

Percentage yield

A

The practical efficiency of the process

(actual mass / theoretical) x 100

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8
Q

How can you measure mass accurately?

A
  1. measure mass on 2 or 3 dp balance of a weighing bottle with required quantity of solid in it
  2. empty mass into reaction vessel
  3. reweigh empty weighing bottle
  4. first reading - mass of empty weighing bottle gives the exact mass added
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