Chem 101 Chandra Homework Ch 3,

How many hours would Charles have to swim to lose 1.0 lb? Express the energy in kilocalories to two significant figures.

10 h The calculation of the time needed to lose a pound while swimming is as follows: 1.0 lb×3500 kcal1 lb×1 h340 kcal

Part C How many hours would Charles have to walk to lose 1.0 lb? Express the energy in kilocalories to two significant figures.

22 h This equates to walking for approximately 3 h every day for a week. Some of this time could be saved by incorporating a more rigorous activity during the week.

Problem 3.34 with feedback - Clinical Application For lunch, a patient consumed 3 oz of skinless chicken, 3 oz of broccoli, 1 medium apple, and 1 cup of carrots (see the table below). Food Carbohydrate (g) Fat (g) Protein (g) Energy (kcal) Energy (kJ) Apple, 1 medium 15 0 0 60 260 Banana, 1 medium 26 0 1 110 460 Beef, ground, 3 oz 0 14 22 220 900 Broccoli, 3 oz 4 0 3 30 120 Carrots, 1 cup 11 0 2 50 220 Chicken, no skin, 3 oz 0 3 20 110 450 Egg, 1 large 0 6 6 70 330 Milk, nonfat, 1 cup 12 0 9 90 350 Potato, baked 23 0 3 100 440 Salmon, 3 oz 0 5 16 110 460 Steak, 3 oz 0 27 19 320 1350 You may want to reference ( pages 76 - 79) Section 3.5 while completing this problem. Part A How many kilocalories did the patient obtain from the lunch? Express the energy as an integer and include the appropriate units.

250 kcal The total number of kilocalories is the sum of 110 kcal+30 kcal+60 kcal+50 kcal.

Problem 3.82 A large bottle containing 821 g of water at 3 ∘C is removed from the refrigerator. Part A How many kilojoules are absorbed to warm the water to room temperature of 22∘C? Express your answer to two significant figures and include the appropriate units.

65 kJ

Classify each of the following pure substances as an element or a compound.1.a silicon (Si) chip 2.oxygen (O2) 3.hydrogen peroxide (H2O2) 4.rust (Fe2O3) 5.methane (CH4) in natural gas Drag the appropriate items to their respective bins.

Element: A silicon chip, m oxygen Compound: Hydrogen peroxide, rust, methane in natural gas

Classify each type of matter as an element, a compound, a heterogeneous mixture, or a homogeneous mixture. Drag each item to the appropriate bin.

Element: aluminum, magnesium, platinum Compound: Carbon monoxide, toluene, sugar Heterogeneous mixture: apple juice with pulp, soil Homogeneous mixture: Hot coffee, salt water, air A mixture can contain substances in different states. For example, a glass of ice water contains solid ice and liquid water.

Classifying Matter Matter is anything that takes up space and has mass. Matter is classified in many different ways, including by its state (solid, liquid, or gas) and by its composition (pure substances or mixtures). The blue spheres below represent atoms. What state of matter is depicted by each graphic? Drag each item to the appropriate bin.

Graphic A( lots of packed molecule)s Solid Graphic B (6 molecules moving rapidly) gas Graphic C (about 10-15 molecules) liquid

Core Chemistry Skill: Identifying Physical and Chemical Changes Matter has both physical and chemical properties and can undergo physical or chemical changes. Physical properties are those that a substance displays without changing its composition, whereas chemical properties are evident only during a chemical change (also called a chemical reaction). In contrast, when a substance undergoes a physical change, it may change appearance, but not its composition. Part B Classify each of the properties as a physical property or a chemical property. Drag each item to the appropriate bin.

Physical Property: the color of copper wire, the smell of vinegar, the melting point of butter, the luster of silver jewelry Chemical Property: the explosiveness of fireworks, the flammability of ethanol, the reactivity of iron with oxygen

Core Chemistry Skill: Identifying Physical and Chemical Changes Matter has both physical and chemical properties and can undergo physical or chemical changes. Physical properties are those that a substance displays without changing its composition, whereas chemical properties are evident only during a chemical change (also called a chemical reaction). In contrast, when a substance undergoes a physical change, it may change appearance, but not its composition. Part A Classify each of the changes as a physical change or a chemical change. Drag each item to the appropriate bin.

Physical change: carving wood, tearing aluminum foil, freezing of water, slicing an apple Chemical change: bleaching skin, frying an egg, burning paper, silver tarnishing When tarnish forms on silver, the outer layer of silver atoms has reacted with sulfur to become a new substance, silver sulfide.

In a chemical reaction, a mixture of salicylic acid and methanol was heated at 76 ∘C for two hours. After completion of the reaction, the mixture is cooled to 30 ∘C. Part A What is this temperature in Fahrenheit degrees? Express your answer to three significant figures.

T = 169 ∘F

In a chemical reaction, a mixture of salicylic acid and methanol was heated at 76 ∘C for two hours. After completion of the reaction, the mixture is cooled to 30 ∘C. Part B What is this temperature in kelvins? Express your answer to three significant figures.

T = 349 K

You may want to reference ( pages 76 - 79) Section 3.5 while completing this problem. Part A During one week, Charles swam for a total of 3.0 h and walked for a total of 9.0 h . If Charles expends 340 kcal/h swimming and 160 kcal/h walking, how many total kilocalories did he expend for one week? Express the energy in kilocalories to two significant figures.

total for one week = 2500 kcal Charles expended 1000 kcal of energy swimming and 1400 kcal of energy walking.

Part B If the loss of 3500 kcal is equal to a loss of 1.0 lb, for the amount of exercise that Charles did for one week in Part A, how much weight, in pounds, did he lose? Express the energy in kilocalories to two significant figures.

weight loss in one week = 0.70 lb The equality given, 3500 kcal/lb, is used as a conversion factor to calculate the weight loss that corresponds to the energy expenditure in Part A. The value of 3500 kcal should be in the denominator to allow the units of energy to cancel.