HOW DO YOU BALANCE A CHEMICAL EQUATION?

CHEMICAL EQUATIONS NEED TO BE BALANCE SO THAT YOUR EQUATION REFLECTS THE LAW OF CONSERVATION OF MASS. THE TOTAL MASS OF THE REACTANTS MUST EQUAL THE TOTAL MASS OF THE PRODUCTS. THIS MEANS THAT THE NUMBER OF ATOMS OF EACH ELEMENT IN THE REACTANTS MUST BE EXACTLY EQUAL TO THE NUMBER OF ATOMS OF EACH ELEMENT IN THE PRODUCTS.

TO BALANCE A CHEMICAL EQUATION YOU PLACE NUMBERS IN FRONT OF THE FORMULAS OF THE SUBSTANCE AS NEEDED. IF YOU DON'T WRITE A NUMBER IN FRONT OF THE FORMULA OF A SUBSTANCE THEN IT IS UNDERSTOOD THAT YOU USE ONE (1) OF THAT FORMULA. THESE "NUMBERS IN FRONT" ARE KNOWN AS COEFFICIENT.

WHEN BALANCING CHEMICAL EQUATIONS, YOU NEED TO REMEMBER TO NEVER CHANGE ANY SUBSCRIPTS IN ANY FORMULA. THE SUBSCRIPTS DEFINE THE SUBSTANCE AS THAT SUBSTANCE. WHEN YOU CHANGE A SUBSCRIPT YOU WOULD BE CHANGING THE COMPOSITION OF THE SUBSTANCE AND NO LONGER WOULD HAVE THE SAME SUBSTANCE.

TO LEARN HOW TO BALANCE CHEMICAL EQUATIONS YOU WILL HAVE TO READ A VARIETY OF SOURCES. ALSO, MAKING MODELS OF THE SUBSTANCES INVOLVED IN THE EQUATIONS MAY HELP. YOU CAN USE JU JUBES, MARSHMALLOWS OR BEADS TO REPRESENT ATOMS. TOOTHPICKS OR PIPE CLEANERS CAN BE USED TO ATTACH ATOMS TOGETHER TO MAKE MOLECULES.

TEXTBOOKS YOU CAN READ:

• CHEMICALS IN ACTION - PAGES 180 TO 182
• SCIENCE 10 - PAGES 226 TO 229
• JUST ABOUT ANY CHEMISTRY TEXTBOOK

INTERNET SITES

• SITE A
• SITE B
• SITE C
• SITE D
• SITE E
• SITE F

AFTER YOU THINK YOU UNDERSTAND THE BASIC PROCESS OF BALANCING A CHEMICAL EQUATION, PROCEED WITH THE ACTIVITY AND ASSIGNMENT.

ACTIVITY

GO TO THIS SITE TO PRACTICE BALANCING EQUATIONS ON LINE. REMEMBER TO READ THE INSTRUCTIONS ON HOW TO USE THE SITE. KEY INSTRUCTION: IF YOU USE ONLY 1 MOLECULE OF SOMETHING IN THE BALANCING PROCESS, YOU MUST TYPE THE 1.

GO HAVE FUN!

ASSIGNMENT

YOU WILL BALANCE THE CHEMICAL EQUATIONS IN THE ATTACHED ASSIGNMENT SHEET. YOU WILL LIKELY WANT TO PRINT A COPY OF THE ASSIGNMENT, DO THE ASSIGNMENT ON PAPER AND THEN FAX YOUR TEACHER A COPY OF YOUR WORK. CHOOSE YOUR ASSIGNMENT FORMAT:

• WORD FORMAT
• RICH TEXT FORMAT
• PDF DOCUMENT

WHEN YOU HAVE FINISHED BALANCING THE EQUATIONS, COMPARE YOUR WORK WITH THE WORK DONE BY ANOTHER CLASSMATE. DISCUSS ANY DIFFERENCES YOU FIND. MAKE ANY CHANGES TO YOUR OWN ASSIGNMENT THAT YOU DEEM NECESSARY.

CHECK YOUR ASSIGNMENT ANSWERS BY OBTAINING THE ANSWER KEY FROM YOUR TEACHER. SEND YOUR ANSWER TO YOUR TEACHER. YOUR TEACHER WILL THEN SEND YOU A COPY OF THE CORRECT ANSWERS OR MAKE AN ANSWER KEY AVAILABLE ON THE WEB FOR YOU.

ASSESSMENT

YOU WILL BE EVALUATED ON YOUR SKILL IN BALANCING CHEMICAL EQUATIONS WHEN YOU WRITE YOUR UNIT TEST.