Quiz #4

A solution of lead (II) nitrate is added to aqueous potassium iodide and a precipitate of lead (II) iodide and aqueous potassium nitrate is formed.

a) Write a word equation for the reactionb) Write a skeleton equatonc) Write a balanced chemical equationd) What type of chemical reaction is this?

What is an Acid?

• A substance that produces H+ ions in solution• **an acid is only an ‘acid’ when dissolved in

solution (water) – must be aqueous.

What is a Base?

Most bases are substances that produce hydroxide ions (OH-) when dissolved in water.

What is an Indicator?

• Are chemicals that change colour in the presence of acids or bases.

• Many indicators will change one colour in an acid and another colour in a base.

• We can use the characteristic colour change of an indicator to identify a substance as being an acid or base.

The pH scale

• pH = power of hydrogen• A scale that measures the concentration of

hydrogen ions in solution.

• 0 ---acidic--- 7 (neutral)--basic– 14 -the lower the pH, -the higher the pH,

the more H+ is the less H+ is present present (lower concentration)(higher concentration)

Quiz #5

Hydrogen gas and oxygen gas are put under electrolysis to produce water.

1. Write the word equation2. Write the skeleton equation3. Write a balanced chemical equation4. What type of reaction is this?

Fluorine gas reacts with hydrochloric acid to produce hydrofluoric acid and chlorine gas.

1. Word2. Skeleton3. Balanced4. Type of reaction