C9

Question 1

Formula for mass in grams of moles

Answer 1

Mass (g) % relative atomic mass

Question 2

Moles in molecules/particles/atoms

Answer 2

Number of particles % (6.02 X 10²³)

Question 3

How to calculate concentration of a solution and it’s unit

Answer 3

Concentration= Amount dissolved
—————————
Volume of solution

The unit is (g/dm³)

(TO CONVERT CM TO DM³ DIVIDE BY 1000)

Question 4

What’s the molecular formula and what is it for

Answer 4

Molecular formula=

Mass of molecular formula
—————————————————-
Mass of empirical formula

The molecular formula is to find the actual number of atoms in a compound of elements

Question 5

What’s an element and a compound

Answer 5

An element is a pure substance of the periodic table and a compound is a mixture of elements

Question 6

What does Ar, RMM and Mr mean

Answer 6

Ar = Relative atomic mass, the weight in grams of atoms in an element (Carbon -> 12g)

Mr + RMM = the relative molecular mass of a compound in sum

(Oxygen (O² -> 16 X 2 = 32g)

Question 7

What’s titration

Answer 7

A technique where a solution of known concentration is used to determine the concentration of an unknown solution

Question 8

What’s a mole

Answer 8

A mole of a substance is it’s relative atomic mass or relative formula mass in grams

(O -> 16 -> 1 mole)

(O²-> (16 X 2) 32 -> 2 moles)

Question 9

How do I calculate the moles in a liquid solution

Answer 9

N = Concentration n/dm³ / volume in dm³

Question 10

percentage yield formula

Answer 10

Percentage yield = mass of product actually made / theoretical mass of products X 100

Question 11

What’s atom economy and what is it used for

Answer 11

It’s used to know the efficiency of a products sale.

Atom economy= total molecular mass of desired product / sum of molecular mass of all products X 100

Question 12

What is used in titration

Answer 12

Acid is added to a burette to a fixed volume of alklali in a conical flask and the pipette measures out an accurate amount of alkali so that the indicator reaction is followed. Once the indicator changes colour is when a neutral solution has formed

Question 13

How do I calculate Mr + RMM (Relative formula mass + Relative molecular mass)

Answer 13

1.M r of CO 2 = 12 + 16 + 16 = 44.

2.M r of CO 2 = (1 × 12) + (2 × 16) = 12 + 32 = 44

Question 14

What’s empirical formula?

Answer 14

It tells you the simple ratio of a compound of elements