calculations

Question 1

What is atomic number?

Answer 1

The number of protons in the nucleus of an atom.

Question 2

What is an electron?

Answer 2

A negatively charged particle that orbits the nucleus at fixed energy levels.

Question 3

What is the relative mass of an electron?

Answer 3

1/1836.

Question 4

What is relative atomic mass?

Answer 4

The weighted mean mass of an atom compared with 1/12th mass of a carbon atom.

Question 5

What is relative isotopic mass?

Answer 5

The mass of an atom of an isotope compared with 1/12 mass of an atom of carbon-12.

Question 6

What is relative formula mass?

Answer 6

weighted mean mass of a formula unit compared to 1/12 the mass of a carbon -12 atom

Question 7

What is relative molecular mass?

Answer 7

the weighted mean mass of a molecule compared to 1/12 mass of a carbon -12 atom

Question 8

What is the charge of carbonate?

Answer 8

CO3. 2-

Question 9

What is the charge of hydroxide?

Answer 9

OH. 1-

Question 10

What is the charge of nitrate?

Answer 10

NO3. 1-

Question 11

What is the charge of sulfate?

Answer 11

SO4. 2-

Question 12

What is the charge of zinc ion?

Answer 12

Zn. 2+

Question 13

What is the amount of substances?

Answer 13

The quantity that has moles in its units, used as a way of counting atoms.

Question 14

How can the amount of substances be calculated?

Answer 14

Using mass (n=m/M) or volume concentration (n=CV).

Question 15

What does anhydrous mean?

Answer 15

A crystalline compound containing no water.

Question 16

What is atom economy?

Answer 16

A measure of the amount of starting materials that ends up as useful products.

Question 17

Why is a high atom economy good?

Answer 17

It means that a process is sustainable and less waste is produced.

Question 18

What is the formula for % atom economy?

Answer 18

% atom E = (mass of desired/ sum of all reactants masses) x100.

Question 19

What is an empirical formula?

Answer 19

The simplest whole number ratio of atoms of each element present in a compound.

Question 20

What does hydrated mean?

Answer 20

A crystalline compound that contains water.

Question 21

What is an ideal gas?

Answer 21

A gas which has molecules that occupy negligible space with no interactions between them.

Question 22

What is the ideal gas equation?

Answer 22

pV = nRT.

Question 23

What is a mole?

Answer 23

The amount of any substance containing as many particles as there are carbon atoms in exactly 12g of carbon-12 isotope.

Question 24

What is percentage yield?

Answer 24

The percentage ratio of the actual yield of products from a reaction compared with the theoretical yield.

Question 25

What does Avogadro’s constant represent?

Answer 25

The number of atoms per mole of the carbon-12 atom.

Question 26

What is the mass formula?

Answer 26

mass = n x Mr.

Question 27

What is Avogadro’s law?

Answer 27

Under the same temperature and pressure, one mole of any gas would occupy the same volume.

Question 28

What is the ideal gas equation in terms of pressure and volume?

Answer 28

Pressure (Pa) x volume (m3) = moles (n) x gas constant (8.314 J mol-1) x temp (K).

Question 29

What is the concentration equation?

Answer 29

n = cV.

Question 30

What is molar mass?

Answer 30

Mass of 1 mole of substance.

Question 31

What is the symbol for molar mass?

Answer 31

M.

Question 32

What is the unit for molar mass?

Answer 32

g/mol.

Question 33

What does atom economy indicate?

Answer 33

How much of the mass of the reactants is converted into useful products.

Question 34

What is the % atom economy formula?

Answer 34

Not provided.

Question 35

What is meant by the term standard solution?

Answer 35

A solution of known concentration.

Question 36

work out the empirical formula of sodium oxide given that 0.69g of sodium combines with 0.24g oxygen

Answer 36

Na2O