Chemistry intro

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Calcium Carbonate is found in chalk!

Slide 10

Oxidation/Reduction Reactions

A reaction in which electrons are transferred from one atom to another.

Oxidation: The loss of electrons by an atom

Reduction: The gain of electrons by an atom.

EXAMPLE:

Take a penny, file of the copper to expose the zinc in the inside.

Place it in HCl, and zinc is oxidized.

Zn(s) + HCl(aq) Zn2+(aq) + Cl - (aq) + H2(g)

Zinc gains a positive charge, and is oxidized.

Slide 11

Acid-Base Neutralization Reactions

When an acid reacts with a base to yield water and a salt.

Acid= compounds that produce H+ ions when dissolved in water

Base= compounds that produce OH- ions when dissolved in water.

Neutralization involves H+ and OH- ions and always yields water (H2O) and a salt.

Demo: a typical example:

HCl + NaOH H2O + NaCl

Slide 12

Chemical Reaction Inquiry Lab: “Chemical Baggie Science”

Students are given the following three chemicals:

1. Calcium chloride - CaCl2 2. Sodium Bicarbonate - NaHCO3 3. Bromothymol Blue

They are also given a 10 ml graduated cylinder and plastic baggies. They are told that they must try every combination possible from the three chemicals that they are given. The reactions can be conducted in sealed plastic baggies. After making some initial observations, students must conduct an experiment of their choice based on the scientific method.

Slide 13

Hot Pack/ Cold Pack Lab/Demo

Locate the chemicals that are in hot packs and cold packs.

Demonstrate how the packs work by performing two different kinds of reactions.

Endothermic and Exothermic

Elephant’s Toothpaste

Mix: Saturated Solution of Manganese Dioxide with 12% solution of Hydrogen Peroxide and detergent. You can add stripes of food coloring for dramatic effect.

Slide 14

The End