quantitive chem c3

Question 1

what is the law of the conservation of mass

Answer 1

no atoms are lost or made during a chemical reaction so mass of reactants equals the mass of products

Question 2

what is the relative atomic mass

Answer 2

average mass of all isotopes

Question 3

how to calculate the number of moles in an element

Answer 3

mass (g) / relative atomic mass

Question 4

how to calculate the number of moles in a compound

Answer 4

mass (g) / relative formula mass

Question 5

what is avogadros constant

Answer 5

1 mole which is 6.02 x10(-23)

Question 6

what does concentration tell us

Answer 6

a mass of a solute in a given volume of a solution

Question 7

what is a solute

Answer 7

a chemical which is dissolved in a solvent

Question 8

whats the equation for concentration

Answer 8

mass (g) / volume (dm3)

Question 9

why is it not always possible to achieve 100% yield

Answer 9

• some product may be lost
• not all reactant react in correct way
• reversible reactions may not go to completion

Question 10

what is the equation for percentage yield

Answer 10

mass of product actually made /
max theoretical product
x100

Question 11

what is atom economy

Answer 11

a measure of the amount of reactants which end up as useful products

Question 12

what is the equation for atom economy

Answer 12

mass of desired products /
mass of all products
x100