C6 Chemical calculations with mass

Question 1

What is conservation of mass?

Answer 1

atoms are not created or destroyed; just rearranged

Question 2

When a metal forms a metal oxide, why does the mass increase?

Answer 2

atoms from gaseous oxygen have been added

Question 3

When an acid reacts with a metal, why does the mass decrease?

Answer 3

a gas is produced and escapes

Question 4

What is relative formula mass?

Answer 4

sum of the relative atomic masses of each atom in a substance

Question 5

What is a mole?

Answer 5

mass of a substance that contains 6.02 x 10^23 particles

Question 6

Avogadro’s constant

Answer 6

6.02 x 10^23

Question 7

What formula is used to calculate the number of moles?

(mass, MR, moles)

Answer 7

moles= mass/mr

Question 8

What is a limiting reactant?

Answer 8

the reactant that is completely used up in a chemical reaction

Question 9

What is the unit for concentration?

Answer 9

g/dm^3 or mol/dm^3

Question 10

What formula is used to calculate concentration?

(mass, volume, concentration)

Answer 10

conc = mass/ volume

Question 11

How can you convert a volume reading from cm^3 to dm^3?

Answer 11

divide by 1000

Question 12

If the amount of solute in a solution increases, what happens to concentration?

Answer 12

increases