« Return to AACT homepage

# AACT Member-Only Content

You have to be an AACT member to access this content, but good news: anyone can join!

# Dimensional Analysis and Unit Conversion (15 Favorites)

LESSON PLAN in Quantitative Chemistry, Dimensional Analysis, SI Units. Last updated May 30, 2017.

### Summary

In this lesson, students will learn how to use dimensional analysis for unit conversion problems.They will then practice the skill on several chemistry-based conversion problems.

### Grade Level

High School

### Objectives

By the end of this lesson, students should be able to

- use dimensional analysis for mass, length, volume, temperature, and density unit conversion problems

### Chemistry Topics

This lesson supports students’ understanding of

- unit conversion
- dimensional analysis

### Time

**Teacher Preparation**: 5 minutes

**Lesson**: 45 – 60 minutes

### Materials

- Dimensional Analysis PowerPoint presentation
- Student Handout

** **

### Safety

- No specific safety precautions need to be noted.

### Teacher Notes

- Show your students The Temperature Guys video from the Founders of Chemistry video series on the AACT website, before starting the unit conversion lesson. This will help to begin a discussion about why units are important.
- Use the supplied PowerPoint presentation to guide your student through a few examples of unit conversion problems using dimensional analysis.
- The lesson opener asks, “When does 0.5 – 60 = 11?”The answer – it all depends on units.A half (0.5) day is 12 hours. Subtract one hour (60 minutes) and you get 11 hours.
- Have 100 pennies, 10 dimes, 4 quarters, and 1 dollar bill ready for the second slide.Ask students what the four have in common (same amount of money) and how they differ (each has a different monetary value and you need different amounts of each to have a dollar)
- Have a meter stick that also has inch markings.Talk about the metric markings and how they are related.Then compare the inch markings to the centimeters markings.
- You may want to follow this lesson with the Unit Conversion Online Tutorial activity.

### For the Student

### Lesson

**Dimensional Analysis Practice Problems**

** **

- Convert 3.55 liters into milliliters.
- Convert 1.64 pounds to grams and milligrams.
- Convert 7.2 meters to centimeters and inches.
- Convert 16,450 milligrams to grams and pounds.
- Convert 12.0 feet into centimeters and meters.
- Convert 1.500 days into minutes and seconds.
- The highest temperature recorded in Washington D.C. was 106°F on July 20, 1930.Convert the temperature to °C and K.
- On the 4
^{th}of July, a sparkler burns at a temperature of 1644K.Convert the temperature to both °C and °F. - I like my steak cooked medium rare – which means it will have an internal temperature of 135°F.Convert this temperature to °C and K.
- A student finds a rock on the way to school. In the laboratory he determines that the volume of the rock is 22.7 cm
^{3}, and the mass in 39.943 g. What is the density of the rock? - Calculate the density of a material that has a mass of 52.457 g and a volume of 13.5 cm
^{3}. - The density of zinc is approximately 7.13 g/mL.
- What is the volume, in cm
^{3}, of a 5.00 g piece of zinc? - What is the mass of a 45.6 L block of zinc?

- What is the volume, in cm
- A sample of iron has a volume of 25.0 cm
^{3}has a mass of 174 grams.Calculate the density of iron.- What would be the mass of 15.0 of cm
^{3}iron? - What would be the volume of 1000. grams of iron?

- What would be the mass of 15.0 of cm