Catalyst – October 5 2, 2010 Monday Mystery Element! 1. Like most rare earth metals, used to make phosphors in TVs 2. Ferromagnetic (attracted to magnets) 3. Tarnishes slowly, oxide flakes off

Catalyst – October 5 2, 2010 Monday Mystery Element! 1. Like most rare earth metals, used to make phosphors in TVs 2. Ferromagnetic (attracted to magnets) 3. Tarnishes slowly, oxide flakes off GADOLINIUM (#64)

Today’s Agenda  Catalyst  New Groups  Diving into Balancing Equations  Practice  Exit Question TONIGHT’S HW: BALANCING WORKSHEET

Today’s Objectives  SWBAT apply law of conservation of mass to chemical reactions by balancing chemical equations.

White Board Door into class LR 3 rd Period Group 4 Kendell, Tracy, Shawn, Sara Group 3 Allesandro, Melvin, Paula, Tashelle Group 1 Ariel, Kiedra, Bao, Amber Group 2 Chicobi, Corey, Marissa, Jamie Group 5 Warren, Tigler, Quanetta, Jasmine, Waynell Group 6 Ebony, Brandon, Kara, Melvin Group 8Group 7Group 9

White Board Door into class LR 4 th Period Group 4 Stephanie, Kim, Lizzeh, Eddie Group 3 Jeremy, Roniece, Lyndon, Kourtney Group 1 Kentrell, Khallid, Rachel, Kim Group 2 Caleb, Infinity, Dwanyetta, Troy Group 5 Jytte’, Jaron, Artrel, Nia Group 6 Josh’shawn, Aaron, Jon, Chelsie Group 8 Rodrea, Lester, Chelsie Group 7 Chelsie, Shannon, Sam, Darreal Group 9

REVIEW: Balancing equations RULES!  Key Point #1: When balancing equations, never, Never, NEVER change subscripts, only coefficients!

Coefficient  A coefficient is a whole number that comes in front of the compound formula, never in the middle!  You multiply the coefficient to all the numbers in the compound 2 AlCl 3

REVIEW: L-C-M!!!  Key Point #2: Chemical reactions MUST follow the Law of Conservation of Matter. What is the LCM?  Matter cannot be created or destroyed.  If 3 carbons are in the reactants of a reaction, then there darn well better be 3 carbons in the products of a reaction.

Independent Practice Worksheet!

Balancing with diatomics…  Key Point #1: Sometimes with diatomics, you must be a little tricky.  C 4 H 10 + O 2  CO 2 + H 2 O

Diatomics  If you reach the point in a balance problem where everything is balanced except the diatomic atom...  You can only get even numbers with diatomics…  2 O 2 = 4 O atoms  3 O 2 = 6 O atoms  And sometimes the other side is odd  Use a fraction, then multiply by 2

Example: Work it out… C 4 H 10 + O 2  CO 2 + H 2 O

Your Turn… 1. C 6 H 6 + O 2  CO 2 + H 2 O 2. C 10 H 22 + O 2  CO 2 + H 2 O

Balancing with some hot sauce…  What if you have some polyatomic ions?  WHAAAAAAAAT will you do??  Key Point #2: When balancing equations that involve polyatomic ions, keep them together!

Work it out…  ___ H 3 PO 4 + ___ KOH  ___ K 3 PO 4 + ___ H 2 O  Which polyatomics are we using?  PO 4 – phosphate  OH – hydroxide  Where is the OH on the other side?  It’s OK – rewrite H 2 O as HOH – Trust me!

Work it out…  __ H 3 (PO 4 ) + __ K(OH)  __ K 3 (PO 4 ) + __ H(OH)  Which polyatomics are we using?  PO 4 2- – phosphate  OH 1- – hydroxide

Your Turn! Write a blank before each formula… 1. HCl + NaOH  NaCl + H 2 O 2. NaOH + H 2 CO 3  Na 2 CO 3 + H 2 O 3. Al(OH) 3 + H 2 CO 3  Al 2 (CO 3 ) 3 + H 2 O

Class/Homework Time! WORKSHEET! You must complete 24 problems for HW…extra points for extra problems!

Exit Question  Balance one of the following equations: 1. __KClO 3 ---> __KCl + __O 2 2. __S 8 + __O 2 ---> __SO 3 HOMEWORK: BALANCING WKSHT (24 Problems)