Balancing equation Use visualizer is better

Chemical equation 2 No There are 3 H in the products Word equation: potassium + water potassium hydroxide solution + hydrogen Chemical equation: K (s) + H2O (l)  KOH (aq) + H2(g) reactants products 2 How many H in the reactants? Is it equal to the number of H in the products? No There are 3 H in the products

What can we do? Balance it! Chemical equation: K (s) + H2O (l)  KOH (aq) + H2(g) 2 H(Hydrogen) in reactants 3 H (Hydrogen) in the products We can’t change to H3O

What can we do? Balance it! 2 Chemical equation: K (s) + H2O (l)  KOH (aq) + H2(g) 2 2 H(Hydrogen) in reactants 3 H (Hydrogen) in the products We can’t change to KOH2, but we can multiple KOH by 2

What can we do? Balance it! 2 Chemical equation: K (s) + H2O (l)  KOH (aq) + H2(g) 2 2 H(Hydrogen) in reactants 4 H (Hydrogen) in the products

What can we do? Balance it! 2 2 Chemical equation: K (s) + H2O (l)  KOH (aq) + H2(g) 2 2 2 H(Hydrogen) in reactants 4 H (Hydrogen) in the products multiple by 2 in the beginning

What can we do? Balance it! 2 2 However…….. K …. Chemical equation: K (s) + H2O (l)  KOH (aq) + H2(g) 2 2 4 H(Hydrogen) in reactants 4 H (Hydrogen) in the products YEAH~~~Hydrogen is now balanced~~ Oxygen is now balanced~~~ However…….. K ….

What can we do? Balance it! 2 2 2 Chemical equation: K (s) + H2O (l)  KOH (aq) + H2(g) 2 2 2 Don’t worry~ Write 2 in front of K, it will be balanced~

What can we do? Balance it! Chemical equation: 2 K (s) + 2 H2O (l)  2 KOH (aq) + H2(g)

Challenge Exercise: Hydrogen + oxygen  water Write the chemical equation with the correct states of matter 2H2(g) + O2(g)  2H2O (l)

Common ions Cations Li+ Na+ K+ Group I Mg2+ Ca2+ Group II Al3+ Group III Common metals: Ag+ Cu+ Cu2+ Fe2+ Zn2+ Pb2+

Anions F- Cl- Br- I- Group VII O2- Group VI Polyatomic Ion: OH- (hydroxide) NO3- (nitrate) CO32- (carbonate) SO42- (sulphate)