Presentation is loading. Please wait.

Presentation is loading. Please wait.

CHEMISTRY CHAPTER 4 PROBLEM SOLVING IN CHEMISTRY.

Similar presentations


Presentation on theme: "CHEMISTRY CHAPTER 4 PROBLEM SOLVING IN CHEMISTRY."— Presentation transcript:

1 CHEMISTRY CHAPTER 4 PROBLEM SOLVING IN CHEMISTRY

2 Steps for solving word problems: 1. Find unknown 2. Find knowns 3. Plan solution 4. Calculate 5. Check

3 A conversion factor is a ratio with a value of one. Ex. 1 ft = 12 inches 1.00g water = 1 mL water 100 cm = 1m

4 Dimensional Analysis is also called the “factor label method” of problem solving.

5 Ex m = ____ mm 52.5 m x 1000 mm = 5.25 x 10 4 mm 1m or 52.5m 1000mm = 5.25 x 10 4 mm 1m

6 Ex km = ____ cm 73.2 km 1000m 1 km 73.2 km 1000m 100 cm 1 km 1m = 7.32 x 10 6 cm

7 How many seconds are there in 2.5 years? 2.5 years 365 days 1 year 2.5 years 365 days 24 hours 1 year 1 day 2.5 years 365 days 24 hours 60 min 1 year 1 day 1 hour 2.5 years 365 days 24 hours 60 min 60 s 1 year 1 day 1 hour 1 min = 7.9 x 10 7 s

8 A clock gains 0.25 seconds per minute. How many seconds will it gain in exactly 180 days? 180 days 24 hr 1 day 180 days 24 hr 60 min 1 day 1 hr 180 days 24 hr 60 min 0.25s gained 1 day 1 hr 1 min =6.48 x 10 4 s gained = 6.5 x 10 4 s gained

9 A fictitious unit of length called the “zither” is defined by the relationship 7.50 cm = 1.00 zither. How many zithers are in a meter distance? 100.0m 100cm 1 m 100.0m 100cm 1.00 zither 1 m 7.50 cm = 1333 zithers = 1330 zithers

10 What is the mass of a 35.0 mL sample of concentrated sulfuric acid (density 1.84g/mL)? 35.0 mL 1.84g 1 mL = 64.4 g

11 Nolan Ryan threw a fastball mi/h. Calculate this velocity in m/s. 1 mi = km mi 1 h mi km 1 h 1 mi mi km 1000 m 1 h 1 mi. 1 km mi km 1000 m 1hr 1 h 1 mi. 1 km 60 min mi km 1000 m 1hr 1 min 1 h 1 mi. 1 km 60 min 60 s m/s

12 The density of copper is 8.96g/cm 3 at 25 o C. Determine its density in kg/m g 1 cm g 1kg 1 cm g 8.96g 1kg (100) 3 cm 3 1 cm g 1m 3 =8960 kg/m 3 or 8.96 x 10 3 kg/m 3

13 Copper makes up 1.1 x percent by mass of a normal healthy human. How many grams of copper would be found in the body of a person weighing 150 lb? (1.0 kg = 2.2 lb) 150 lb man 1.0kg man 2.2 lb man 150 lb man 1.0kg man 1000g man 2.2 lb man 1 kg man 150 lb man 1.0kg man 1000g man 1.1 x g Cu 2.2 lb man 1 kg man 100g man = 7.5 x g Cu or 0.075g Cu


Download ppt "CHEMISTRY CHAPTER 4 PROBLEM SOLVING IN CHEMISTRY."

Similar presentations


Ads by Google