Catalyst – November 44-32, Write the SKELETON EQUATION for: Liquid carbon disulfide reacts with oxygen gas, producing carbon dioxide gas and sulfur dioxide gas. 2. BALANCE the following equation: Al + FeO  Al 2 O 3 + Fe Reflect on Weekly Goal!

Today’s Agenda  Catalyst  Group of the Week  HW Questions?  Evidence of Chemical Reactions – Notes and LAB!  Work Time  Exit Question

Today’s Objectives  SWBAT record observations of chemical reactions.  SWBAT describe how we know that chemical reactions occur (evidence!).

Don’t forget! A chemical change is a process involving one or more substances changing into NEW SUBSTANCES!! This is also called a CHEMICAL REACTION!!

Today’s Class  Today, you will be learning about different ways we can tell if a reaction takes place  You will be observing chemical reactions and taking notes at the same time, so stay focused!

Rules for today 1. Stay focused and on task. 2. When Mr. Jhaveri says “GO,” read the directions and perform reaction. 3. After the reaction, observe the products and record. 4. When Mr. Jhaveri says “NOTES,” look up at board and copy notes as Mr. Jhaveri discusses the reaction. Ask questions if you have them!

Reaction #1 Vinegar + Baking Soda HC 2 H 3 O 2 (aq)+ NaHCO 3 (s)  NaC 2 H 3 O 2 (aq) + H 2 O (l) + CO 2 (g)

Reaction #1 FORMATION OF A GAS INDICATES A CHEMICAL REACTION. When a gas forms in a liquid, we see BUBBLES!

Reaction #2 Sodium Hydroxide + Copper(II) Chloride NaOH (aq) + CuCl 2 (aq)  NaCl (aq)+ Cu(OH) 2 (s)

Reaction #2 FORMATION OF A PRECIPITATE INDICATES A CHEMICAL REACTION.  A precipitate is a solid produced during a chemical reaction; a precipitate is not soluble in the reaction solution (does not dissolve)

Reaction #3 Citric Acid + Baking Soda H 3 C 6 H 5 O 7 (aq) + NaHCO 3 (aq)  NaC 6 H 5 O 7 (aq)+ H 2 O (l) + CO 2 (g)

Reaction #3 TEMPERATURE CHANGE INDICATES A CHEMICAL REACTION. When temperature goes up or down…

Reaction #4 Mr. Jhaveri will turn water into wine!

Reaction #4 COLOR CHANGE INDICATES A CHEMICAL REACTION.

Guided Practice Question  SCENARIO: Tyreion wanted to see what happened when she mixed a couple chemicals. She mixed baking soda and vinegar together. After mixing the two chemicals, she observed bubbles forming in the beaker.  QUESTION: Did a chemical reaction occur? Support your answer using COMPLETE SENTENCES.

Guided Practice Question  SCENARIO: Blake wanted to see what would happen if he mixed water and salt together. After adding the salt and stirring, he observed that the salt seemed to disappear.  QUESTION: Did a chemical reaction occur? Support your answer using COMPLETE SENTENCES.

Independent Practice Question  SCENARIO: Alexis is interested in learning about two compounds, silver (I) nitrate and sodium chloride. She decides to dissolve each compound in water and mix them. When she does this, she sees a white solid form.  QUESTION: Did a chemical reaction occur? Support your answer using COMPLETE SENTENCES.

Independent Practice Question  SCENARIO: Johnny puts 2 grams of salt into a beaker filled with a clear unknown liquid. The salt appears to disappear into the liquid  QUESTION: Did a chemical reaction occur? Support your answer using COMPLETE SENTENCES.

Independent Practice Question  SCENARIO: Oscar was curious about what would happen if he mixed zinc and hydrochloric acid. After doing so, the mixture bubbles and fizzes.  QUESTION: Did a chemical reaction occur? Support your answer using COMPLETE SENTENCES.

Practice Questions  ps/chm/100/dgodambe/thedisk/chemrxn/signs.ht m

Sum It Up! Think about all four chemical reactions you performed or saw today. What are some characteristics of chemical reactions? How do you know they happen? Write your answer in at least three complete sentences!

Exit Question 1. What is a chemical reaction? 2. What are some examples of evidence of a chemical reaction?