A recipe calls for 3.0 Tablespoons of salt to make a loaf of bread. You want to make 3 loaves of bread. If a Tablespoon is 3.3 cm 3, how many cm 3 of salt will you need? A. 9.9 cm 3 B. 9.0 cm 3 C. 30 cm 3 D cm 3 solution

3 loaves Tablespoons 1 loaf 3.3 cm 3 Tablespoon =29.7 cm 3 2 significant figures 30 cm 3

A trip from LAX to Hawaii is 2650 miles. How far is that in km? 1 mile = 1600 meters A km B km C X 10 6 km D. 4,000 km solution

2650 miles m 1 mile 1 km 1000 m =4,240 km

A cube is mm X mm X 410 mm. What is its volume in cm 3 ? A. 198 cm 3 B cm 3 C. 2.0 X 10 4 cm 3 D. 440 cm 3 solution

220 mm 1 1 m 1000 mm 100 cm 1 m =22 cm Similarly: 410 mm =41 cm Volume = length x width x height V = 22 cm(22 cm)(41 cm) = cm 3 2 significant figures = 2.0 X 10 4 cm 3

There are grams of hydrogen in one mole. One mole of a gas has a volume of 22.4 L. If you have 33 L of hydrogen, how many grams does it weigh? A. 1.5 grams B. 745 grams C grams D. 63 grams solution

33 Litres 1 1 mole 22.4 Litres grams 1 mole =1.485 grams 2 significant figures, 1.5 grams

You’ve probably all seen the demonstration where a card is put over the mouth of a glass of water and when the glass is flipped over and the card is released, the water doesn’t fall out. This is caused by the air pressure pushing up being stronger than the weight of the water pushing down. The cup that was used for this demo holds 110 mL of water. One mL of water weighs one gram. Air pressure is 13.5 pounds per square inch (lbs/sq. in.). How many square inches must the cup be for this trick to work? (1 pound = 453 grams) A. 18 in 2 B..20 in 2 C..018 in 2 D. 12 in 2 solution

110 ml 1 1 gram 1 mL 1 pound 453 grams 1 sq. inch 13.5 pounds = sq. in. 2 significant figures,.018 sq. in.