chemistry unit

Neutralization Reaction

• A double displacement reaction

• occurs when acids and bases are mixed

• neutralizes both substances

• Forms water and a salt

The hydroxide ion (OH-) and hydrogen (H+) ions

react to form

Water

The metal cation and non-metal anion combine to form a

Salt

The goal of neutralization reaction

to from products with a pH closer to 7 (neutral)

Predicting the Products of Neutralization Reactions

If we know the reactants of a neutralization

reaction, we can predict the products by using the

double displacement model.

Chemical Spills and Neutralization Reactions

• Sulfuric acid (H2SO4) and sodium hydroxide

(NaOH)

• calcium oxide/ lime Ca0(s) was added

1.CaO(s) + H2O(l) → Ca(OH)2 (aq)

2. Ca(OH)2 (aq) + H2SO4 (aq) → 2H 2O(l) + CaSO4 (aq)

Antacids

• Acidic stomach acid can irritate the stomach lining

• Antacids contain hydroxide and carbonate neutralize stomach acid

• Milk of magnesia Mg(OH)2 is not very soluble in water so it produces a low concentration of hydroxide atoms, so it doesn’t cause chemical burns but provides relief

What’s the PH of stomach

1.5

Neutral pH

A pH level of 7, indicating a neutral solution.

Double Displacement Model

A method used to predict the products of reactions between two ionic compounds.

Calcium Oxide (CaO)

A chemical compound used in the neutralization of sulfuric acid during chemical spills.

Milk of Magnesia

A common antacid that contains magnesium hydroxide (Mg(OH)2) and is used to neutralize stomach acid.

Products of Neutralization

Water and salt formed as a result of an acid-base neutralization reaction.

Element groups

Alkali metals

Highly reactive

Alkaline earth metals

Reactive

Halogens

Highly reactive

Noble gases

Not reactive/stable

What are the five main types of chemical reactions?

Synthesis, Decomposition, Single Displacement, Double Displacement, Combustion

What occurs in a synthesis reaction?

Two or more reactants combine to form a new larger product.

What is the general pattern for a synthesis reaction?

A + B → AB

What occurs in a decomposition reaction?

One compound breaks down into two or more smaller compounds or elements.

What is the general pattern for a decomposition reaction?

AB → A + B

What happens in a single displacement reaction?

One element takes the place of another element in a compound.

What is the general pattern for a single displacement reaction?

AB + C → AC + B

Provide an example of a single displacement reaction involving metals.

2HCl + Mg → MgCl2 + H2

What occurs in a double displacement reaction?

The metal ions of two different compounds exchange places.

What is the general pattern for a double displacement reaction?

AB + CD → AD + CB

What is a complete combustion reaction?

Reactions involving the burning of hydrocarbons with oxygen, producing carbon dioxide and water.

Blue, hottest flames, most efficient way to burn energy

What is the general pattern for a complete combustion reaction?

CxHy + O2 → CO2 + H2O

What is an incomplete combustion reaction?

Reactions involving the burning of hydrocarbons with limited oxygen, producing carbon, carbon monoxide, carbon dioxide, and water.

Produces yellow, sooty and cooler flames

What is the general pattern for an incomplete combustion reaction?

CxHy + O2 → C(s) + CO + CO2 + H2O

What is corrosion?

The breakdown of metal as a result of chemical reactions with its environment.

What is the Maillard reaction?

A series of chemical reactions between amino acids and sugars in food, leading to browning and flavor development.

What did Svante Arrhenius discover?

ions were present in aqueous solutions like acids and bases

What ions do acids produce when dissolved in water?

H+ (hydrogen ions)

What ions do bases produce when dissolved in water?

OH- (hydroxide ions)

What is the pH range for acids?

pH < 7

What is the pH range for bases?

pH > 7

What taste is characteristic of acids?

Sour taste

What taste is characteristic of bases?

Bitter taste

Feel of acids

Not slippery

Feel of bases

slippery

Acid reactivity

Reacts with most metals (usually to produce H+ gas)

Base reactivity

No reaction with metals

Acids and bases are

• Soluble in water

• Can be corrosive

• Electrolytes present (forms charged ions in water = conductor of electricity)

What is a common use of hydrochloric acid?

Stomach acid and adjusting swimming pool acidity

What is the formula for hydrochloric acid?

HCl(aq)

What is a common use of sulfuric acid?

Car batteries, making detergents, and cleaning steel

What is the formula for sulfuric acid?

H2SO4(aq)

What is a common use of phosphoric acid?

Tart taste in soft drinks

What is the formula for phosphoric acid?

H₃PO₄(aq)

What is a common use of Ascetic acid?

vinegar

What is the formula for acetic acid?

HC2H3O2(aq)

What is a common use of sodium hydroxide?

• making soap

• removing grease

What is the formula for sodium hydroxide?

NaOH(aq)

What is a common use of magnesium hydroxide?

Antacid medicine

What is the formula for magnesium hydroxide?

Mg(OH)2(aq)

What is a common use of magnesium hydroxide?

Controlling the acidity of soil and pool water

What is the formula for calcium hydroxide?

Ca(OH)2(aq)

Acids usually

have hydrogen as the cation and some other anion

Binary acids

contain 2 elements

binary acid naming

• Hydrogen becomes “hydro”

• Non-metal’s name changes from “-ide” to “-ic”add “acid” at the end

oxyacids

• acids with oxygen in the formula

• associated with polyatomic ions

oxyacid naming

• Drop the hydrogen

• “-ate” ending on the polyatomic ion becomes “-ic”

• add “acid” at the end

Bases always

Have hydroxide ions as the anion with some other metal as the cation

Base naming

• Bases are named as any other ionic compound with an hydroxide ion

• Other bases are unique → Ex. ammonia - NH₃

What happens to the '-ate' ending of a polyatomic ion in oxyacids?

It becomes '-ic' when naming the acid.

Chemical Formulas of Acids and Bases

Chemical formulas are the same as its ionic compound counterpart, but the symbol (aq) is added to show that it has been dissolved in water.

What is an indicator?

• A chemical that changes color in the presence of an acid or a base.

• Each has a different range in which it changes colour

Natural Indicators

Tea, Litmus, Cabbage juice

Synthetic Indicators

Phenolphthalein, Bromothymol Blue, Methyl Orange

What does the pH scale measure?

• The strength of acids and bases

• 0-14 indicates the level of acidity or alkalinity (basicity) of a solution

What determines a solutions pH value

The concentration of hydrogen ions relative to hydroxide ions disssolved in a solution

Lower pH

More acidic

Higher pH

More basic/alkaline

pH scale

pH stands for

Power of hydrogen

Strength of acids and bases

Depends on how well it can form ions when it dissolves in solution

A strong acid/base

Completely separates into its constituent ions

A weak acid/base

Partially separates into its constituent ions

What does a lower pH indicate?

A more acidic solution.

What does a higher pH indicate?

A more basic (alkaline) solution.

What color does bromothymol blue turn in an acid?

Yellow

What color does bromothymol blue turn in an base?

Blue

What color does phenolphthalein turn in a base?

Pink

pH is a logarithmic scale

A change in 1 pH unit represents a 10-fold increase or decrease in H+ ion concentration

What is the formula for nitric acid?

HNO3(aq)

What is the formula for potassium hydroxide?

KOH(aq)

What color does phenolphthalein turn in an acid?

Colorless

What color does phenolphthalein turn in a base?

Pink

What color does litmus paper turn in an acid?

Red

What color does litmus paper turn in a base?

Blue

Placement of things on the ph scale

types of chemical reactions

1. Synthesis

2. Decomposition

3. Single Displacement

4. Double Displacement

5. Combustion

What occurs in a synthesis reaction?

Two or more reactants combine to form a new larger product.

general pattern for a synthesis reaction

A + B → AB

What occurs in a decomposition reaction?

One compound breaks down into two or more smaller compounds or elements.

General pattern for a decomposition reaction

AB → A + B

What happens in a single displacement reaction?

One element takes the place of (displaces) another element in a compound.