Chem Equations

Question 1

Number of moles

Answer 1

Mass in grams/ mr

Question 2

What is oxidation and reduction in terms of electrons?

Answer 2

Oxidation is loss and reduction is gain

Question 3

Oxidation and reduction in terms of oxygen

Answer 3

Oxidation is gain and reduction is loss

Question 4

How to calculate uncertainty

Answer 4

Range/2

Question 5

Concentration equation

Answer 5

Mass of solute/volume of solvent

Question 6

How many molecules atoms or ions are in one mole of a substance

Answer 6

6.02 x 10 to the power of 23

Question 7

Nanoparticle size

Answer 7

1-100 nm

Question 8

Describe how to carry out titration

Answer 8

Measure out known volume of acid and place in conical flask
Place conical flask on white tile under burette
Fill with alkali of known concentration
Add an indicator
Add alkali drop by drop swirling each time until reaction reaches its end point

Question 9

What does metal and acid form

Answer 9

Salt and hydrogen

Question 10

What does metal and water form

Answer 10

Metal hydroxide and hydrogen

Question 11

Concentration units

Answer 11

g/dm cubes or mol/dm cubed

Question 12

How does a fuel cell works

Answer 12

An external source of fuel ie oxygen or air or hydrogen

The fuel is oxidised electrochemically to produce a potential difference

Question 13

Fine particle size

Answer 13

100 to 2500nm

Question 14

How much volume does nitrogen occupy

Answer 14

24dm cubed

Question 15

How to calculate mass produced when something is thermally decomposed

Answer 15

1.) make sure equation is balanced
2.) calculate the mr of CaCO3 cubed and the mr of CO2
Mr of CaCO = 100 and Mr of CO2 = 44
3.)find out what 1g of substance is (100/100) Caco cubed and 44/100 CO2
1 gram of CaCo 3 would produce 0.44 grams of CO2
4.) multiply both sides by 50 to work out what 50g it CaCo cubed would make
50 grams of CaCO3 would make (0.44 x 50 grams) of CO2
50g of CaCO3 would make 22 grams of Co2

Question 16

Volume of gas

Answer 16

Mass of glass/ mr of gas x24

Question 17

% yield

Answer 17

Actual yield/theoretical yield x 100

Question 18

% atom economy

Answer 18

Mr of desired product/ sum Mr of all reactants x 100

Question 19

Forces between ions in an ionic bond

Answer 19

Electrostatic

Question 20

Radius of a nucleus

Answer 20

0.1 nm

Question 21

How many times smaller is nucleus then atom

Answer 21

Less then 1/10000 of the atom

Question 22

% mass

Answer 22

Ar X number of atoms in an element/ mr of compound x100

Question 23

Calculate relative atomic mass

Answer 23

(75% x 35) + (25% x 37)

Question 24

Order of reactivity least to most

Answer 24

Least: copper, iron, zinc, mag, calc, lith, sodium, potassium

Question 25

Calculate mass of magnesium needed to produce 4.6 tonnes of magnesium oxide

Answer 25

1. ) balance equation
2. ) Calculate mr (2Mg = 48, mr of 2MgO = 80)
3. ) 48 tonnes of mag produces 80 tonnes of mag oxide
4. ) find out amount of mag needed to produce one tonne of mag oxide (48/80) magnesium and (80/80) mag oxide. 0.6 tonnes of mag therefore produces 1 tonne of mag oxide
5. ) multiply both sides by 4.6 to work out how much magnesium is needed (0.6 X 4.6) = 2.76