CHEMISTRY

November 10, 2011

Brain Teaser

Identify the type of reaction: H2 + O2 H2O CaSO4 + KOH Ca(OH) 2 + K2SO4

KClO3 KCl + O2

AgNO3 + Cu Cu(NO3) 2 + Ag

Write the chemical equation: Magnesium reacts with chlorine gas in the

air to form magnesium chloride

Agenda

Brain Teaser Review Types of Reactions Notes: Balancing Equation Cool Chemical Reactions Mini-Lab Homework

Complete Reaction Types Worksheet 1 Balance Equations in Lab Packet

Review

4 Types of Chemical Reactions Synthesis: A + B AB (1 product) Decomposition: (1 reactant) AB A + B Single replacement: X + AB XB + A Double replacement: AB + XY AY + XB

Balancing Equation

Word Equations Describes a chemical reaction that occurs

using the names of the chemicals involved. Reactants versus Products An arrow is written between the reactants

and products to indicate that chemical change is occurring For example: 2H2 + O2 2H2O

Balancing Equation

Atoms involved in a chemical reaction must be balanced. Same number of atoms of each element on both

sides of a chemical equation. Unbalanced equation

Balance the equation by adding coefficients in front of the compounds Coefficients: number of molecules of a particular

compound Subscripts: number of atoms of each element in the

compound

Balancing Equation

A. Write the word equationB. Write the CORRECT formula for all reactants

and productsC. Balance the equation by using coefficients

1. NEVER change the subscripts in the formula to balance the equation

2. Elements need to be balanced from either side of the equation

3. Start with the first element and work right of the equation

4. Balance the number of oxygen and hydrogen atoms after all the other elements have been balanced.

5. Go back and double check that all elements are balanced

6. BOX your coefficients when finished7. USE PENCIL only!

Balancing Equation

Inspection Method Algebraic Method

Balancing Equation

Inspection Method Aluminum reacts with oxygen to produce

aluminum oxide

Chlorine reacts with lithium bromide to produce lithium chloride and bromine gas

Balancing Equation

Algebraic Method Aluminum oxide reacts with sodium phosphate

to produce aluminum phosphate and sodium oxide

Hydrogen gas and nitrogen monoxide react to form water and nitrogen gas

Practice Problems

___Ca(CN)2 + __AlF3 __CaF2 + ___Al(CN)3 Potassium phosphate + Calcium hydroxide Calcium phosphate + Potassium

hydroxide

Balancing Chemical Equations Refer to Practice Worksheet

Cool Chemical Reactions

Objectives: Write 4 chemical equations to explain the chemical

reactions Balance the equations Record qualitative observations

Procedures: Read each procedure carefully before beginning.

Goggles are required! Restore Station Before Switching DO NOT dump any chemicals down the sink

Waste Waste Container DO NOT cross contaminate chemicals Burning Split Test

Oxygen Gas Carbon Dioxide Gas Hydrogen Gas

Cool Chemical Reactions

Station 1: The Sparkler Hold Mg strip with tongs and ignite with Bunsen

burner Station 2: The Fire Extinguisher

Place 1 little scoop of sodium bicarbonate (2 cm deep) into a test tube

Add drops of HCl slowly into the test tube (fizz) Have a burning splint ready to test for the gas

produced Discard solution into the sink and was clean test

tube

Cool Chemical Reactions

Station 3: Spy Writing Dip one end of Q-tip in lead (II) nitrate Draw and Let it Dry Dip other end of Q-tip in potassium iodide Wipe over writing. Let it dry Dipose Q-tip in Waste Container. Wash your

hands! DO NOT TOUCH the chemicals on the paper!

Cool Chemical Reactions

Station 4: Hear it Pop Add a piece of Mg ribbon into a test tube Add 1 pipette full of 3M hydrochloric acid Immediately place a stopper on the test tube

to collect the gas produced Have a burning splint ready to test for the

gas produced. Remove the stopper and test for gas

DO NOT submerge splint into the liquid (DEMO)

Discard content into Waste Beaker

Cool Chemical Reactions

A. Procedure (NEED TO WEAR GOGGLES!)

B. Observations: Refer to Handout C. Write the chemical equation and

BALANCE! Don’t forget Cl2, I2, F2, Br2, O2, H2, N2

D. Refer to the handout

Cool Chemical Reactions Lab ReportRefer to Rubric