Amount Of Substance

Question 1

What is relative atomic mass (Ar)? (1)

Answer 1

Ar = average mass of an atom / 1/12th mass of 1 atom of 12C

Question 2

What is relative molecular mass (Mr)? (1)

Answer 2

Mr = average mass of an molecule / 1/12th mass of 1 atom of 12C

Question 3

What is relative formula mass (Mr)? (1)

Answer 3

Mr = average mass of entity / 1/12th mass of 1 atom of 12C

Question 4

What is Avogadro constant? (1)

Answer 4

The total number of particles in a mole of substance.

Question 5

What is Avogadro’s number? (1)

Answer 5

6.022 x 10(23)

Question 6

What is concentration measured in? (1)

Answer 6

Mol dm(-3)

Question 7

How to calculate concentration? (1)

Answer 7

Concentration mol dm(-3) = moles (n) / volume V dm(3)

Question 8

How to calculate moles? (1)

Answer 8

Mass (g) / Mr

Question 9

What is a mole? (1)

Answer 9

The amount of substance that contains 6.022 x 10(23) particles.

Question 10

How many moles are in the Ar of at element? (1)

Answer 10

The relative atomic mass of any element in grams contains one mole of atoms.

Question 11

How many moles are in the relative molecular mass of a substance? (1)

Answer 11

The relative molecular mass (or relative formula mass) of a substance in grams, contains one mole of entities.

Question 12

What if the equation to work out the number of moles, in terms of mass of a substance? (1)

Answer 12

Number of moles = mass (g) / mass of 1 mole (g)

Question 13

How o calculate the number off moles in a given volume of solution? (1)

Answer 13

Number of moles in solution = concentration mol dm(-3) x volume cm(3) / 1000.

Question 14

What is Boyle’s law, in terms of the ideal gas equation? (1)

Answer 14

The product of pressure and volume is constant as long as the temperature remains constant. Thus pressure x volume = constant.

Question 15

What is Charles law, in terms of the ideal gas equation? (1)

Answer 15

The volume is proportional to the temperature as long as the pressure remains constant. Thus, volume = temperature and volume / temperature= a constant.

Question 16

What is Gay-Lussac’s law or the constant volume law, in terms of the ideal gas equation? (1)

Answer 16

The pressure is proportional to the temperature as long as the volume remains constant. Thus, pressure =temperature and pressure / temperature = constant.

Question 17

What s the ideal gas equation? (1)

Answer 17

Pressure x volume = moles x gas constant x temperature

Question 18

What is temperature measured in,in terms of the deal gas equation? (1)

Answer 18

K, to get this add 273 to the degree.

Question 19

What is gas constant measured in? (1)

Answer 19

J K(-1) mol(-1)

Question 20

What is volume measured in?(1)

Answer 20

M(3), to get this for dm(3) divide by 1000, for cm(3) divide by 1,000,000.

Question 21

What is pressure measured in, in terms of the ideal gas equation? (1)

Answer 21

Pa, to get this, if kPa multiple by 1000, for MPa multiple by 1,000,000.

Question 22

What is the empirical formula? (1)

Answer 22

The formula that represents the simplest whole number ratio of atoms of ah element present in a compound.

Question 23

What is the molecular formula? (1)

Answer 23

Gives the actual number of atoms of each element in one molecule of the compound.