Solved: Calculate the amount of heat required to raise the temperature of a 65-g sample

Perform each conversion. (a) 45.6 J to calories (b) 355 cal to joules (c) 43.8 kJ to calories (d) 215 cal to kilojoules

An energy bill indicates that a customer used 1027 kWh in July. How many joules did the customer use?

Perform each conversion. (a) 345 Cal to kilowatt-hours (b) 23 J to calories (c) \(5.7 \times 10^{3}\) J to kilojoules (d) 326 kJ to joules Equation Transcription: Text Transcription: 5.7 x 10^3

Perform each conversion. (a) 25 kWh to joules (b) 249 cal to Calories (c) 113 cal to kilowatt-hours (d) 44 kJ to calories

Problem 55P Complete the table: J cal Cal kWh 225 J ___ 5.38 X 10-2 Cal ___ ___ 8,21 x 105 ___ ___ ___ ___ ___ 295 kWh ___ ___ 155 Cal ___

Problem 56P Complete the table: J cal Cal kWh 7.88 x 106 J 1.88 x 106 cal ___ ___ ___ ___ 1154 Cal ___ ___ 88.4 cal ___ ___ ___ ___ ___ 125 kWh

An adult eats food whose nutritional energy totals approximately \(2.2\times10^3\mathrm{\ Cal}\) per day. The adult burns \(2.0\times10^3\mathrm{\ Cal}\) per day. How much excess nutritional energy, in kilojoules, does the adult consume per day? If 1 lb of fat is stored by the body for each \(14.6\times10^3\mathrm{\ kJ}\) of excess nutritional energy consumed, how long will it take this person to gain 1 lb? Equation Transcription: Text Transcription: 2.0 x 10^3 Cal 2.2 x 10^3 Cal 14.6 x 10^3 kJ

A television uses 32 kWh of energy per year. How many joules does it use?

How many joules of nutritional energy are in a bag of chips with a label that lists 245 Cal? If 1 lb of fat is stored by the body for each \(14.6\times10^3\mathrm{\ kJ}\) of excess nutritional energy consumed, how many bags of chips contain enough nutritional energy to result in 1 lb of body fat? Equation Transcription: Text Transcription: 14.6 x 10^3 kJ

A common type of handwarmer contains iron powder that reacts with oxygen to form an oxide of iron. As soon as the handwarmer is exposed to air, the reaction begins and heat is emitted. Is the reaction between the iron and oxygen exothermic or endothermic? Draw an energy diagram showing the relative energies of the reactants and products in the reaction.

Classify each process as exothermic or endothermic. (a) gasoline burning in a car (b) isopropyl alcohol evaporating from skin (c) water condensing as dew during the night

In a chemical cold pack, two substances are kept separate by a divider. When the divider is broken, the substances mix and absorb heat from the surroundings. The chemical cold pack feels cold. Is the reaction exothermic or endothermic? Draw an energy diagram showing the relative energies of the reactants and products in the reaction.

Classify each process as exothermic or endothermic. (a) dry ice subliming (changing from a solid directly to a gas) (b) the wax in a candle burning (c) a match burning

Perform each temperature conversion. (a) \(212\ ^{\circ}\mathrm{F}\) to Celsius (temperature of boiling water) (b) 77 K to Fahrenheit (temperature of liquid nitrogen) (c) \(25\ ^{\circ}\mathrm{C}\) to kelvins (room temperature) (d) \(98.6\ ^{\circ}\mathrm{F}\) to kelvins (body temperature) Equation Transcription: Text Transcription: 212 deg F 25 deg C 98.6 deg F

Perform each temperature conversion. (a) \(102\ ^{\circ}\mathrm{F}\) to Celsius (b) 0 K to Fahrenheit (c) \(-48\ ^{\circ}\mathrm{C}\) to Fahrenheit (d) 273 K to Celsius Equation Transcription: Text Transcription: 102 deg F -48 deg C

The warmest temperature ever measured in the United States was \(134\ ^{\circ}\mathrm{F}\) on July 10, 1913, in Death Valley, California. Convert that temperature to degrees Celsius and Kelvin. Equation Transcription: Text Transcription: 134 deg F

The coldest temperature ever measured in the United States was \(-80\ ^{\circ}\mathrm{F}\) on January 23, 1971, in Prospect Creek, Alaska. Convert that temperature to degrees Celsius and Kelvin. (Assume that \(-80\ ^{\circ}\mathrm{F}\) is accurate to two significant figures.) Equation Transcription: Text Transcription: -80 deg F

Vodka does not freeze in the freezer because it contains a high percentage of ethanol. The freezing point of pure ethanol is \(-114\ ^{\circ}\mathrm{C}\). Convert that temperature to degrees Fahrenheit and Kelvin. Equation Transcription: Text Transcription: -144 deg C

Liquid helium boils at 4.2 K. Convert this temperature to degrees Fahrenheit and Celsius.

The temperature in the South Pole during the Antarctic winter is so cold that planes cannot land or take off, effectively leaving the inhabitants of the South Pole isolated for the winter. The average daily temperature at the South Pole in July is \(-59.7\ ^{\circ}\mathrm{C}\). Convert this temperature to degrees Fahrenheit. Equation Transcription: Text Transcription: -59.7 deg C

The coldest temperature ever recorded in Iowa was \(-47\ ^{\circ}\mathrm{F}\) on February 3, 1998. Convert this temperature to Kelvins and degrees Celsius. Equation Transcription: Text Transcription: -47 deg F

Complete the table.

Complete the table.

Calculate the amount of heat required to raise the temperature of a 65-g sample of water from \(32\ ^{\circ}\mathrm{C}\) to \(65\ ^{\circ}\mathrm{C}\). Equation Transcription: Text Transcription: 32 deg C 65 deg C

Calculate the amount of heat required to raise the temperature of a 22-g sample of water from \(7\ ^{\circ}\mathrm{C}\) to \(18\ ^{\circ}\mathrm{C}\). Equation Transcription: Text Transcription: 7 deg C 18 deg C

Calculate the amount of heat required to heat a 45-kg sample of ethanol from \(11\ ^{\circ}\mathrm{C}\) to \(19\ ^{\circ}\mathrm{C}\). Equation Transcription: Text Transcription: 11 deg C 19 deg C

Calculate the amount of heat required to heat a 3.5-kg gold bar from \(21\ ^{\circ}\mathrm{C}\) to \(67\ ^{\circ}\mathrm{C}\). Equation Transcription: Text Transcription: 21 deg C 67 deg C

If 89 J of heat are added to a pure gold coin with a mass of 12 g, what is its temperature change?

If 57 J of heat are added to an aluminum can with a mass of 17.1 g, what is its temperature change?

An iron nail with a mass of 12 g absorbs 15 J of heat. If the nail was initially at \(28\ ^{\circ}\mathrm{C}\), what is its final temperature? Equation Transcription: Text Transcription: 28 deg C

A 45-kg sample of water absorbs 345 kJ of heat. If the water was initially at \(22.1\ ^{\circ}\mathrm{C}\), what is its final temperature? Equation Transcription: Text Transcription: 22.1 deg C

Calculate the temperature change that occurs when 248 cal of heat are added to 24 g of water.

A lead fishing weight with a mass of 57 g absorbs 146 cal of heat. If its initial temperature is \(47\ ^{\circ}\mathrm{C}\), what is its final temperature? Equation Transcription: Text Transcription: 47 deg C

An unknown metal with a mass of 28 g absorbs 58 J of heat. Its temperature rises from \(31.1\ ^{\circ}\mathrm{C}\) to \(39.9\ ^{\circ}\mathrm{C}\). Calculate the heat capacity of the metal and identify it referring to Table 3.4. Equation Transcription: Text Transcription: 31.1 deg C 39.9 deg C

When 2.8 J of heat are added to 5.6 g of an unknown metal, its temperature rises by \(3.9\ ^{\circ}\mathrm{C}\). Are these data consistent with the metal being gold? Equation Transcription: Text Transcription: 3.9 deg C

When 56 J of heat are added to 11 g of a liquid, its temperature rises from \(10.4\ ^{\circ}\mathrm{C}\) to \(12.7\ ^{\circ}\mathrm{C}\). What is the heat capacity of the liquid? Equation Transcription: Text Transcription: 10.4 deg C 12.7 deg C

When 47.5 J of heat are added to 13.2 g of a liquid, its temperature rises by \(1.72\ ^{\circ}\mathrm{C}\). What is the heat capacity of the liquid? Equation Transcription: Text Transcription: 1.72 deg C

Two identical coolers are packed for a picnic. Each cooler is packed with eighteen 12-oz soft drinks and 3 lb of ice. However, the drinks that went into cooler \(A\) were refrigerated for several hours before they were packed in the cooler, while the drinks that went into cooler \(B\) were at room temperature. When the two coolers are opened three hours later, most of the ice in cooler \(A\) is still ice, while nearly all of the ice in cooler \(B\) has melted. Explain. Equation Transcription: Text Transcription: A B

A 100-g block of iron metal and 100 g of water are each warmed to \(75\ ^{\circ}\mathrm{C}\) and placed into two identical insulated containers. Two hours later, the two containers are opened and the temperature of each substance is measured. The iron metal has cooled to \(38\ ^{\circ}\mathrm{C}\) while the water has cooled only to \(69\ ^{\circ}\mathrm{C}\). Explain. Equation Transcription: Text Transcription: 75 deg C 38 deg C 69 deg C

Calculate the final temperature of 245 mL of water initially at \(32\ ^{\circ}\mathrm{C}\) upon absorption of 17 kJ of heat. Equation Transcription: Text Transcription: 32 deg C

Calculate the final temperature of 32 mL of ethanol initially at \(11\ ^{\circ}\mathrm{C}\) upon absorption of 562 J of heat. (density of ethanol = 0.789 g/mL) Equation Transcription: Text Transcription: 11 deg C

A pure gold ring with a volume of \(1.57\mathrm{\ cm}^3\) is initially at \(11.4\ ^{\circ}\mathrm{C}\). When it is put on, it warms to \(29.5\ ^{\circ}\mathrm{C}\). How much heat does the ring absorb? (density of gold = \(19.3\mathrm{\ g}/\mathrm{cm}^3\)). Equation Transcription: Text Transcription: 1.57 cm^3 11.4 deg C 29.5 deg C 19.3 g/cm^3

A block of aluminum with a volume of \(98.5\mathrm{\ cm}^3\) absorbs 67.4 J of heat. If its initial temperature is \(32.5\ ^{\circ}\mathrm{C}\), what is its final temperature? (density of aluminum = \(2.70\mathrm{\ g}/\mathrm{cm}^3\)) Equation Transcription: Text Transcription: 98.5 cm^3 32.5 deg C 2.70 g/cm^3

How much heat in kilojoules is required to heat 56 L of water from \(85\ ^{\circ}\mathrm{F}\) to \(212\ ^{\circ}\mathrm{F}\)? Equation Transcription: Text Transcription: 85 deg F 212 deg F

How much heat in joules is required to heat a 43-g sample of aluminum from \(72{ }^{\circ} \mathrm{F}\) to \(145^{\circ} \mathrm{F}\)?

What is the temperature change in Celsius when 29.5 L of water absorbs 2.3 kWh of heat?

If 1.45 L of water is initially at \(25.0\ ^{\circ}\mathrm{C}\), what is its temperature after absorption of \(9.4\times10^{-2}\ kWh\) of heat? Equation Transcription: Text Transcription: 25.0 deg C 9.4 x 10^-2 kWh

A water heater contains 55 gal of water. How many kilowatt-hours of energy are necessary to heat the water in the water heater by \(25\ ^{\circ}\mathrm{C}\)? Equation Transcription: Text Transcription: 25 deg C

A room contains 48 kg of air. How many kilowatt-hours of energy are necessary to heat the air in the house from \(7^\circ \mathrm C\) to \(28^\circ \mathrm C\)? The heat capacity of air is \(1.03 ~\mathrm{J/g}~^\circ \mathrm C\).

A backpacker wants to carry enough fuel to heat 2.5 kg of water from \(25\ ^{\circ}\mathrm{C}\) to \(100.0\ ^{\circ}\mathrm{C}\). If the fuel she carries produces 36 kJ of heat per gram when it burns, how much fuel should she carry? (For the sake of simplicity, assume that the transfer of heat is 100% efficient.) Equation Transcription: Text Transcription: 25 deg C 100.0 deg C

A cook wants to heat 1.35 kg of water from \(32\ ^{\circ}\mathrm{C}\) to \(100.0\ ^{\circ}\mathrm{C}\). If he uses the combustion of natural gas (which is exothermic) to heat the water, how much natural gas will he need to burn? Natural gas produces 49.3 kJ of heat per gram. (For the sake of simplicity, assume that the transfer of heat is 100% efficient.) Equation Transcription: Text Transcription: 32 deg C 100.0 deg C

Evaporating sweat cools the body because evaporation is endothermic and absorbs 2.44 kJ per gram of water evaporated. Estimate the mass of water that must evaporate from the skin to cool a body by \(0.50\ ^{\circ}\mathrm{C}\), if the mass of the body is 95 kg and its heat capacity is \(4.0\mathrm{\ J}/\mathrm{g}^{\circ}\mathrm{C}\). (Assume that the heat transfer is 100% efficient.) Equation Transcription: Text Transcription: 0.50 deg C 4.0 J/g deg C

When ice melts, it absorbs 0.33 kJ per gram. How much ice is required to cool a 12.0-oz drink from \(75\ ^{\circ}\mathrm{F}\) to \(35\ ^{\circ}\mathrm{F}\), if the heat capacity of the drink is \(4.18\mathrm{\ J}/\mathrm{g}^{\circ}\mathrm{C}\)? (Assume that the heat transfer is 100% efficient.) Equation Transcription: Text Transcription: 75 deg F 35 deg F 4.18 J/g deg C

A 15.7-g aluminum block is warmed to \(53.2\ ^{\circ}\mathrm{C}\) and plunged into an insulated beaker containing 32.5 g of water initially at \(24.5\ ^{\circ}\mathrm{C}\). The aluminum and the water are allowed to come to thermal equilibrium. Assuming that no heat is lost, what is the final temperature of the water and aluminum? Equation Transcription: Text Transcription: 53.2 deg C 24.5 deg C

A 25.0-mL sample of ethanol (density = 0.789 g/mL) initially at \(7\ ^{\circ}\mathrm{C}\) is mixed with 35.0 mL of water (density = 1.0 g/mL) initially at \(25.3\ ^{\circ}\mathrm{C}\) in an insulated beaker. Assuming that no heat is lost, what is the final temperature of the mixture? Equation Transcription: Text Transcription: 7 deg C 25.3 deg C

The wattage of an appliance indicates its average power consumption in watts (W), where 1 W = 1 J/s. What is the difference in the number of kJ of energy consumed per month between a refrigeration unit that consumes 625 W and one that consumes 855 W? If electricity costs $0.15 per kWh, what is the monthly cost difference to operate the two refrigerators? (Assume 30.0 days in one month and 24.0 hours per day.)

A portable electric water heater transfers 255 watts (W) of power to 5.5 L of water, where 1 W = 1 J/s. How much time (in minutes) does it take for the water heater to heat the 5.5 L of water from \(25\ ^{\circ}\mathrm{C}\) to \(42\ ^{\circ}\mathrm{C}\)? (Assume that the water has a density of 1.0 g/mL.)

What temperature is the same whether it is expressed in the Celsius or Fahrenheit scale?

What temperature on the Celsius scale is equal to twice its value when expressed on the Fahrenheit scale?

Classify each as a pure substance or a mixture.

Classify each as a pure substance or a mixture. If it is a pure substance, classify it as an element or a compound. If it is a mixture, classify it as homogeneous or heterogeneous.

This molecular drawing shows images of acetone molecules before and after a change. Was the change chemical or physical?

This molecular drawing shows images of methane molecules and oxygen molecules before and after a change. Was the change chemical or physical?

Global warming refers to the rise in average global temperature due to the increased concentration of certain gases, called greenhouse gases, in our atmosphere. Earth’s oceans, because of their high heat capacity, absorb heat and therefore act to slow down global warming. How much heat would be required to warm Earth’s oceans by \(1.0\ ^{\circ}\mathrm{C}\)? Assume that the volume of water in Earth’s oceans is \(137\times10^7\mathrm{\ km}^3\) and that the density of seawater is \(1.03\mathrm{\ g}/\mathrm{cm}^3\). Also assume that the heat capacity of seawater is the same as that of water. Earth’s oceans moderate temperatures by absorbing heat during warm periods. Equation Transcription: Text Transcription: 1.0 deg C 137 x 10^7 km^3 1.03 g/cm^3

Examine the data for the maximum and minimum average temperatures of San Francisco and Sacramento in the summer and in the winter. (a) Notice the difference between the August high in San Francisco and Sacramento. Why is it much hotter in the summer in Sacramento? (b) Notice the difference between the January low in San Francisco and Sacramento. How might the heat capacity of the ocean contribute to this difference?

Define matter and list some examples.

What is matter composed of?

What are the three states of matter?

What are the properties of a solid?

What is the difference between a crystalline solid and an amorphous solid?

What are the properties of a liquid?

What are the properties of a gas?

Why are gases compressible?

What is a mixture?

What is the difference between a homogeneous mixture and a heterogeneous mixture?

What is a pure substance?

What is an element? A compound?

What is the difference between a mixture and a compound?

What is the definition of a physical property? What is the definition of a chemical property?

What is the difference between a physical change and a chemical change?

What is the law of conservation of mass?

What is the definition of energy?

What is the law of conservation of energy?

Explain the difference between kinetic energy and potential energy.

What is chemical energy? List some examples of common substances that contain chemical energy.

List three common units for energy.

What is an exothermic reaction? Which has greater energy in an exothermic reaction, the reactants or the products?

What is an endothermic reaction? Which has greater energy in an endothermic reaction, the reactants or the products?

List three common units for measuring temperature.

Explain the difference between heat and temperature.

How do the three temperature scales differ?

What is heat capacity?

The following equation can be used to convert Fahrenheit temperature to Celsius temperature. \({ }^{\circ} \mathrm{C}=\frac{\left({ }^{\circ} \mathrm{F}-32\right)}{1.8}\) Use algebra to change the equation to convert Celsius temperature to Fahrenheit temperature. Equation Transcription: Text Transcription: Degree C=(Degree F-32/1.8)

Why are coastal geographic regions normally cooler in the summer than inland geographic regions?

The following equation can be used to convert Celsius temperature to Kelvin temperature. \(\mathrm{K}={ }^{\circ} \mathrm{C}+273.15\) Use algebra to change the equation to convert Kelvin temperature to Celsius temperature. Equation Transcription: Text Transcription: K = degree C + 273.15

Problem 31P Classify each pure substance as an element or a compound. (a)? aluminum (b)? sulfur (c)? methane (d)? acetone

Classify each mixture as homogeneous or heterogeneous. (a) baby oil (b) chocolate chip cookie (c) water and gasoline (d) wine

Classify each mixture as homogeneous or heterogeneous. (a) coffee (b) chocolate sundae (c) apple juice (d) gasoline

Classify each pure substance as an element or a compound. (a) carbon (b) baking soda (sodium bicarbonate) (c) nickel (d) gold

Classify each substance as a pure substance or a mixture. If it is a pure substance, classify it as an element or a compound. If it is a mixture, classify it as homogeneous or heterogeneous. (a) urine (b) pure water (c) SnickersTM bar (d) soil

Classify each substance as a pure substance or a mixture. If it is a pure substance, classify it as an element or a compound. If it is a mixture, classify it as homogeneous or heterogeneous. (a) helium gas (b) clean air (c) rocky road ice cream (d) concrete

Classify each property as physical or chemical. (a) the tendency of silver to tarnish (b) the shine of chrome (c) the color of gold (d) the flammability of propane gas

Classify each property as physical or chemical. (a) the boiling point of ethyl alcohol (b) the temperature at which dry ice sublimes (turns from a solid into a gas). (c) the flammability of ethyl alcohol (d) the smell of perfume

Which of the following properties of ethylene (a ripening agent for bananas) are physical properties, and which are chemical? • colorless • odorless • flammable • gas at room temperature • 1 L has a mass of 1.260 g under standard conditions • mixes with acetone • polymerizes to form polyethylene

Which of the following properties of ozone (a pollutant in the lower atmosphere but part of a protective shield against UV light in the upper atmosphere) are physical, and which are chemical? • bluish color • pungent odor • very reactive • decomposes on exposure to ultraviolet light • gas at room temperature

Classify each change as physical or chemical. (a) A balloon filled with hydrogen gas explodes upon contact with a spark. (b) The liquid propane in a barbecue evaporates away because someone left the valve open. (c) The liquid propane in a barbecue ignites upon contact with a spark. (d) Copper metal turns green on exposure to air and water.

Classify each change as physical or chemical. (a) Sugar dissolves in hot water. (b) Sugar burns in a pot. (c) A metal surface becomes dull because of continued abrasion. (d) A metal surface becomes dull on exposure to air.

A block of aluminum is (a) ground into aluminum powder and then (b) ignited. It then emits flames and smoke. Classify (a) and (b) as chemical or physical changes.

Several pieces of graphite from a mechanical pencil are (a) broken into tiny pieces. Then the pile of graphite is (b) ignited with a hot flame. Classify (a) and (b) as chemical or physical changes.

An automobile gasoline tank holds 42 kg of gasoline. When the gasoline burns, 168 kg of oxygen are consumed and carbon dioxide and water are produced. What total combined mass of carbon dioxide and water is produced?

In the explosion of a hydrogen-filled balloon, 0.50 g of hydrogen reacts with 4.0 g of oxygen. How many grams of water vapor are formed? (Water vapor is the only product.)

Are these data sets on chemical changes consistent with the law of conservation of mass? (a) A 12.8-g sample of sodium completely reacts with 19.6 g of chlorine to form 32.4 g of sodium chloride. (b) An 8-g sample of natural gas completely reacts with 32 g of oxygen gas to form 17 g of carbon dioxide and 16 g of water.

Are these data sets on chemical changes consistent with the law of conservation of mass? (a) A 7.5-g sample of hydrogen gas completely reacts with 60.0 g of oxygen gas to form 67.5 g of water. (b) A 60.5-g sample of gasoline completely reacts with 243 g of oxygen to form 206 g of carbon dioxide and 88 g of water.

In a butane lighter, 9.7 g of butane combine with 34.7 g of oxygen to form 29.3 g carbon dioxide and how many grams of water?

A 56-g sample of iron reacts with 24 g of oxygen to form how many grams of iron oxide?

Perform each conversion. (a) 588 cal to joules (b) 17.4 J to Calories (c) 134 kJ to Calories (d) 56.2 Cal to joules

Problem 31P Classify each pure substance as an element or a compound. (a) aluminum (b) sulfur (c) methane (d) acetone