SCH4U - Chemistry 12 (2024-25) - A

Using the Grass Method to Solve Problems

In this activity you will review how to use the GRASS method when solving problems in physics.  Use this as a reference when solving practice problems and answering questions in assignments.

What is the GRASS method? 

The GRASS method is an organizational tool that allows students to solve problems in an organized and logical way.

Why Use the GRASS Method? 

The GRASS method is useful for both students and teachers. 

For students, using the GRASS method gives students a set of guidelines that helps: 

• organize their solutions 
• uncover the relevant information in a problem 
• find the ultimate goal of the problem
• guide students to the proper tools (equations) to use in solving the problem 

The GRASS method also allows students to clearly demonstrate their understanding of the concepts being assessed.

For teachers, the GRASS method has several benefits: 

• makes sure that all students are presenting their solutions in a uniform format. 
• allows teachers to see the thought process that students are using to solve problems.
• allows teachers to identify areas where students may be struggling or may need additional support.

Using the GRASS Method 

Given - identify the information GIVEN in the problem. 

Required – identify the information REQUIRED (what are you trying to determine).

Analyze – ANALYZE (figure out) which equation, rule or principle applies to this type of problem. 

Solve – if using an equation, substitute the values given in the problem and SOLVE the equation. 

Statement – rewrite your answer as a STATEMENT using a brief sentence that clearly answers the problem.

How to Use the GRASS Method 

When iron is exposed to air, it corrodes to form red-brown rust. Rust is iron (III) oxide (Fe₂O₃). How many moles of iron (III) oxide are contained in 92.2g of pure Fe₂O₃? Round your final answer to three significant digits.