Quantitative Chemistry 😓

Question 1

Define an isotope

Answer 1

An atom with the same amount of protons and electrons, but a different amount of neutrons

Question 2

What is the symbol for relative atomic mass?

Answer 2

Ar

Question 3

What is relative atomic mass?

Answer 3

Average mass of an element relative to 1/12 mass of a ¹²C isotope

Question 4

Difference between mass number and RAM?

Answer 4

Mass number cannot have decimals, whereas RAM can as it is the average

Question 5

What is atom economy?

Answer 5

An indication of the amount of starting material that is converted into useful products

Question 6

Calculation for % atom economy?

Answer 6

Mass of desired product
————————————- ×100
Mass of total reactants

Question 7

What is a mole?

Answer 7

1 mole is the amount of atoms in the the Ar (in grams) of an element

Eg. 1 mole = 12g of C
But 1 mole = 40g of Ca

Question 8

How big is a mole?

Answer 8

6.02 x 10²³

Question 9

What is the mole number called?

Answer 9

Avagadro’s number

Question 10

Equations for how many moles in a certain mass of substance?

Answer 10

. Mass
No. Of moles = ——————–
. RAM or RFM

Question 11

What is empirical formulae?

Answer 11

The simplest ratio of atoms of each element in it.