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Unit Conversions

Chapter 2 MEASUREMENT

West Valley High SchoolGeneral Chemistry

Mr. Mata

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cmgcm

Dimensional Analysis The “Factor-Label” Method

Units, or “labels” are canceled, or “factored” out.

g

Dimensional Analysis Steps:

1. Identify starting & ending units.

2. Line up conversion factors so units cancel.

3. Multiply all top numbers & divide by product of bottom numbers.

4. Check units & final answer.

Dimensional Analysis Lining up conversion factors:

1 in = 2.54 cm2.54 cm 2.54 cm

1 in = 2.54 cm 1 in 1 in

= 1

1 =

Dimensional Analysis Your European hairdresser wants to cut your hair

8 cm shorter. How many inches will he be cutting off?

8 cm 1 in2.54 cm

= 3.1 in

cm in

Dimensional Analysis How many mL are in 1 quart of milk?

1 qt 1 L1.057 qt

= 946 mL

qt mL

1000 mL1 L

Dimensional Analysis How many liters of water would fill a

container that measures 75 in3?

75 in3 2.54 cm3

1 in3= 0.19 L

in3 L

1 L1000 cm3

Dimensional Analysis

A piece of wire is 1.3 m long. How many 1.5-cm pieces can be cut from this wire?

1.3 m 100 cm1 m

= 87 pieces

m pieces

1 piece1.5 cm

Dimensional Analysis You have 1.5 pounds of gold. Find its volume

in cm3 if the density of gold is 19.3 g/cm3.

lb cm3

1.5 lb 1 kg2.2 lb

= 35 cm31000 g

1 kg1 cm3

19.3 g

Dimensional Analysis

West Valley football needs 550 cm for a 1st down. How many yards is this?

550 cm 1 in2.54 cm

= 6.0 yd

cm yd

1 ft12 in

1 yd3 ft

Chapter 2 SUTW Prompt Describe how the measurements of SI

units, conversion factors, & dimensional analysis are used in chemistry.

Complete a 8-10 sentence paragraph using the SUTW paragraph format. Hilite using green, yellow, and pink.

Due Date: Tomorrow (start of class).