The mole concept

Question 1

what is the law of the conservation of mass?

Answer 1

mass cannot be created nor destroyed, only shifted from one form to another

Question 2

in a balanced reaction
mass of ___= mass of ____

Answer 2

reactants and products

Question 3

what does the concept of stoichiometry describe?

Answer 3

describes the relationships between the relative quantities of substances taking part in a reaction or forming a compound

Question 4

stoichiometry is reflected in the ___ of balanced chemical equations

Answer 4

ratios

Question 5

what is a mole?

Answer 5

useful unit of conversion between number of particles and the mass and volume of substances

Question 6

how many particles in one mole of anything? what is this also known as?

Answer 6

6.022 x10^23

Avogadro’s number (NA)

Question 7

how can the number of moles for a given number of particles be determined?

Answer 7

number of moles= number of particles/ avogadro’s number

n=p/NA

Question 8

what is a molar mass?

Answer 8

relative atomic mass indicate the mass of one mole of atoms of that element– this is referred to as molar mass

Question 9

what is the mass of one mole of carbon (use periodic table)

Answer 9

12.01g

Question 10

what is the mass of one mole of sodium (use periodic table)

Answer 10

22.99 g

Question 11

how can the number of moles in a sample of given mass be determined?

Answer 11

number of moles= given mass/ molar mass

n= m/MM