quantitative chemistry

Question 1

what is the law of conservation of mass?

Answer 1

the law of conservation of mass states that no atoms are lost or made in a chemical reaction- so the mass of products equals the mass of reactants

Question 2

what is relative atomic mass

Answer 2

RAM average mass of electrons in an element

Question 3

what is relative formula mass

Answer 3

sum of all atoms in a formula or compound

Question 4

what is Avogadro’s constant?

Answer 4

the number of atoms, molecules or ions in a mole of any give substance. the value of the constant is 6.02 x 10^23

Question 5

mass equals?

Answer 5

Mr x moles

Question 6

concentration (g/dm^3) equals

Answer 6

mass (g) / volume (dm^3)

Question 7

atom economy

Answer 7

(Relative formula mass of desired product ÷ Sum of relative formula masses of all reactants) x 100

Question 8

percentage yield

Answer 8

( Mass of actual yield ÷ Mass of theoretical yield ) x 100

Question 9

volume of gas

Answer 9

mol X 24

Question 10

Avogadro’s law

Answer 10

Equal amounts in moles of gases occupy the same volume under the same conditions of temperature and pressure

Question 11

concentration

Answer 11

The amount of substance (e.g. the mass) in a certain volume of a solution.

Question 12

Uncertainty

Answer 12

All measurements have a degree of uncertainty regardless of precision and accuracy. Uncertainty can be due to the limitations of the measuring equipment or due to the
skill of the experimenter carrying out the measurements