moles

Question 1

Mole is the unit for..

Answer 1

The amount of substance

Question 2

Empirical formula

Answer 2

Shows the simplest whole number ratio of atoms present in a compound

Question 3

Molecular formula

Answer 3

Shows the actual number of atoms of each element of a compound

Question 4

proton relative mass

Answer 4

1

Question 5

proton relative charge

Answer 5

+1

Question 6

neutron relative mass

Answer 6

1

Question 7

neutron relative charge

Answer 7

0

Question 8

electron relative charge

Answer 8

-1

Question 9

electron relative mass

Answer 9

1/1836

Question 10

isotope

Answer 10

different forms of the same element, which have the same number of protons but different number of neutrons

Question 11

atomic number

Answer 11

number of protons

Question 12

relative atomic mass

Answer 12

average mass of the isotopes of the element

Question 13

mass number

Answer 13

number of protons and neutrons

Question 14

empirical formula

Answer 14

the simplest whole number ratio of atoms present in a compound

Question 15

molecular formula

Answer 15

the actual number of atoms of each element present in a molecule

Question 16

vol in dm3

Answer 16

X 24

Question 17

vol in cm3

Answer 17

X 24 000

Question 18

Sources of error in metal oxide combustion prac

Answer 18

• some MgO powder might escape when the lid is lifted
• not all Mg has reacted
• Mg could react with Nitrogen in air

Question 19

Combustion of metal oxide prac

Answer 19

• burn Mg in oxygen and see mass change
• MgO is produced

Question 20

Reduction of metal oxide prac

Answer 20

• tube filled with methane (to remove O2 to prevent an explosion) passes over copper oxide
• ignite excess methane, until black metal is seen
• methane combine with O from CuO to form H2O
• copper has been reduced
• continue passing methane over hot copper to prevent it reacting with methane in the air