Chap 2 - Inorganic Chemistry

The lowest recorded temperature in the continental United States was -69.7 ∘F in Rodgers Pass, Montana, January 20, 1954. Express your answer with the appropriate units.

-56.5 ∘C

Alexandra decides to climb Mt. Krumpett, which is 5000 m high. She determines that this will require a total of 1800kcal of energy for the trip. For her food supply, she decides to take nutrition bars. The label states that each bar contains 50 g of carbohydrates, 10 g of fat, and 40 g of protein. How many nutrition bars should Alexandra pack?

4 bars

If 125 cal of heat is applied to a 60.0-g piece of copper at 25.0∘C , what will the final temperature be? The specific heat of copper is 0.0920 cal/(g⋅∘C) .

47.6 ∘C

Calculate the heat in calories needed to freeze 65g of water at 0 ∘C. Express your answer to two significant figures and include the appropriate units.

5200 cal

The highest recorded temperature in the continental United States was 134 ∘F in Death Valley, California, on July 10, 1913. Express your answer with the appropriate units.

56.7 ∘C

Calculate the heat in calories needed to condense 11.0g of steam at 100∘C. Express your answer to three significant figures and include the appropriate units.

5940 cal

Hot compresses for a patient are prepared with water heated to 145 ∘F. What is the temperature of the hot water in degrees Celsius? Express your answer with the appropriate units.

62.8 ∘C

During extreme hypothermia, a boy's temperature dropped to 20.6 ∘C. What was his temperature on the Fahrenheit scale? Express your answer with the appropriate units.

69.1 ∘F

Calculate the heat in joules needed to freeze 235g of water at 0 ∘C. Express your answer to three significant figures and include the appropriate units.

7.85×10^4 J

Indicate whether heat was absorbed or released in situation above.

absorbed

In a warm room, a person's glasses fog up.

condensation

Heat is removed from 125 g of liquid water at 0∘C.

freezing

Snow on the ground turns to liquid water.

melting

If you pour equal amounts of scalding hot water into different metallic cups of equal temperature, which cup will heat up the most? Rank the cups from hottest to coldest.

Warmest 500-g Silver Cup 500-g Aluminum Cup 750-g Aluminum Cup Coolest

Dry ice in an ice-cream cart disappears.

sublimation

A person uses 820kcal on a long walk. Calculate the energy used for the walk in kilojoules. Express your answer to two significant figures and include the appropriate units.

3400 kJ

The number of hours of running needed to "burn off" the kilocalories in this meal.

1.5 hours

Calculate the heat in joules needed to condense 7.90g of steam at 100∘C. Express your answer to three significant figures and include the appropriate units.

1.79×10^4 J

Calculate the heat in kilojoules needed to melt 3.00kg of ice at 0 ∘C. Express your answer to three significant figures and include the appropriate units.

1000 kJ

How much heat energy is required to raise the temperature of 0.364kg of copper from 23.0 ∘C to 60.0 ∘C? The specific heat of copper is 0.0920 cal/(g⋅∘C) .

1240 cal

Calculate the heat in kilocalories needed to melt 180g of ice at 0 ∘C. Express your answer to two significant figures and include the appropriate units.

14 kcal

A 70.0-kg person has just eaten a quarter-pound cheeseburger (31 g of proteins, 29 g of fats, 34 g of carbohydrates), french fries (3 g of proteins, 11 g of fats, 26 g of carbohydrates), and a chocolate shake (11 g of proteins, 9 g of fats, 60 g of carbohydrates). For the person in the problem, use the table to determine each of the following: The number of hours of sleeping needed to "burn off" the kilocalories in this meal.

18 hours

Calculate the heat in kilojoules needed to vaporize 9.00kg of water at 100∘C. Express your answer to three significant figures and include the appropriate units.

2.03×10^4 kJ

Calculate the heat in kilocalories needed to vaporize 48g of water at 100∘C. Express your answer to two significant figures and include the appropriate units.

26 kcal

A person uses 820kcal on a long walk. Calculate the energy used for the walk in joules. Express your answer to two significant figures and include the appropriate units.

3.4×10^6 J

Which of the following is a physical change? digesting a hamburger burning gas in a car silver jewelry tarnishes melting snow

Melting Snow

Rank the following species according to the decreasing energy needed to raise the temperature of 10.0 g of the substance by 25.0 ∘C. Rank from most to least energy needed

More Energy Needed water aluminum cast iron Copper Silver

What type of change, physical or chemical, takes place in each of the following? Water vapor condenses to form rain. Cesium metal reacts explosively with water. Gold melts at 1064 degrees Celsius. A puzzle is cut into 1000 pieces. Sugar dissolves in water.

Physical Change A puzzle is cut into 1000 pieces. Water vapor condenses to form rain. Sugar dissolves in water. Gold melts at 1064 degrees Celsius Chemical Change Cesium metal reacts explosively with water.

Indicate whether each statement describes potential or kinetic energy.

Potential Energy the energy in your food a tightly wound spring Kinetic energy A car speeding down the freeway an earthquake

Classify each of the following as a pure substance or a mixture: a soft drink a cheese sandwich salt substitute (KCl) propane (C3H8) an iron (Fe) nail

Pure Substance An iron Nail propane salt substitute Mixture A soft Drink A cheese sandwich

Indicate whether heat was absorbed or released in situation above.

released