(L1) Module 1 L1 - Stochiometry

Question 1

What is a limiting reagent?

Answer 1

Reactant that determines amount of product made, by limiting that amount that can be produced.

Question 2

What is a reactant?

Answer 2

Starting material that’s consumed in a chemical reaction to produce products.

Question 3

What is a reagent?

Answer 3

Participates in a chemical reaction, more generalised than reactant as could mean a mixture, element, molecule.

Question 4

What is a co-efficent in stochiometry?

Answer 4

The number before a atom/molecule representing how many are required in order for the equation to be balanced.

Question 5

What is the mole?

Answer 5

Amount of substance that contains the same amount of specified entities as there are atoms in extactly 12g of carbon-12 isotope.

6.022x10^23 particles in 1 mol.

T

Question 6

What is molar mass?

Answer 6

Mass of 1 mol of any entity.
Gathered by adding the molar mass of an individual atoms together from periodic table.

Question 7

What is the mols equation?

Answer 7

n = m/M

Question 8

How to use mass of substance A to find mass of substance B?

Answer 8

mass of A –> mols of A –> use mol ratio to find mols of B –>
mass of B

if 4 mols of Fe react to give 2 mols of Fe2O3 then that’s a
4:2 ratio. 4/2 –> mols of A / 2

Question 9

Calc’ing limiting reagent.

Answer 9

1. Find mols. So n=m/M of each reactant.
2. Compare ratio’s. 2 mols H2 give 2mols h20
   0.66 mols O2x2 is 1.32mols.. when 1.32 mols H2O made, all of the O2 would have been used up.

H2 is reagent in excess while O2 is limiting reagent.

Question 10

Calc’ing excess reagent mass.

Answer 10

1. Find how much reagent had been used in reaction using how much product was able to be made from limiting reagent. e.g 2.50mols -1.32 mols of H2 used =1.18mols
2. chuck into m=n*M… m= 1.18x2.00 = 2.4g

Question 11

Equation for concentration?

Answer 11

c=n/v