Chemistry equations

Question 1

what is the reactivity series?

Answer 1

potassium, sodium, lithium, calcium, magnesium, aluminium, carbon, zinc, iron, hydrogen, copper, silver, gold, platinum

Question 2

how do you find the percentage mass of an element in a compound?

Answer 2

percentage mass of an element in a compound =((Ar × no. atoms of that element) ÷ Mr of the compound) ×100

Question 3

how do you find the number of moles in an amount of substance?

Answer 3

no. of moles= mass in g ÷ Mr

Question 4

what is Avogadro’s number?

Answer 4

6.02 × (10 to the power of 23)

Question 5

how do you find the volume of gas?

Answer 5

volume of gas(dm cubed)= (mass of gas (g) ÷Mr) ×24

Question 6

how do you find the concentration of a solution in g/dm cubed?

Answer 6

concentration (g/dm cubed) = mass of solvent (g) ÷ volume of solvent (dm cubed)

Question 7

how do you find the concentration of a solution in mol/dm cubed

Answer 7

concentration(mol/dm cubed)= no. of moles of solute ÷ volume of solvent (dm cubed)

Question 8

how do you find atom economy?

Answer 8

atom economy= (rfm of desired products ÷ relative formula mass of all reactants) ×100

Question 9

how do you find percentage yield?

Answer 9

percentage yeild= (mass of product actually made ÷ maximum theoretical mass of product) ×100

Question 10

how do you find energy change?

Answer 10

energy change= energy taken in to break bonds - energy given out when making bonds

Question 11

what happens when an acid reacts with an alkali?

Answer 11

acid + alkali = salt + water

AAWS

Question 12

what happens when a base reacts with an acid?

Answer 12

base + acid = water + salt

BAWS

Question 13

what happens when a metal carbonate reacts with an acid?

Answer 13

metal carbonate + acid = water + carbon dioxide + salt

CAWCS

Question 14

what happens when a metal reacts with an acid?

Answer 14

metal + acid = salt + hydrogen