Question 1

Which of the following is an example of a homogeneous mixture used in a real-world application?

Accepted Answer

Brass used in musical instruments

Question 2

A patient is given an intravenous (IV) solution containing sodium chloride dissolved in water. How would you classify this solution?

Accepted Answer

A homogeneous mixture

Question 3

Which of the following best describes the physical state and particle arrangement of a gas?

Accepted Answer

Indefinite shape and volume; particles are far apart and move rapidly

Question 4

Which of the following is a chemical change?

Accepted Answer

Iron rusting in an old car

Question 5

A sample of metal with a mass of 24.8 g absorbs 275 J of energy, causing its temperature to rise from $$21.0\ ^\circ\mathrm{C} to$$ $$39.0\ ^\circ\mathrm{C}. $$What is the specific heat of the metal? Use the formula $$q = m 	imes c 	imes \Delta T.$$

Accepted Answer

$$0.62\ \mathrm{J}/\mathrm{g}\ ^\circ\mathrm{C}$$

Question 6

A cup of whole milk contains 13 g of carbohydrate, 9.0 g of fat, and 9.0 g of protein. Using the energy values $$4\ \mathrm{kcal/g}$$ for carbohydrate, $$9\ \mathrm{kcal/g}$$ for fat, and $$4\ \mathrm{kcal/g}$$ for protein, how many kilocalories does the milk contain (rounded to the tens place)?

Accepted Answer

170 kcal

Question 7

Which of the following statements about the Kelvin temperature scale is correct?

Accepted Answer

It has no negative temperatures and 0 K represents absolute zero.

Question 8

A person with hypothermia has a body temperature of $$34.0\ ^\circ\mathrm{C}. $$What is this temperature in degrees Fahrenheit? Use the formula $$F = 1.8 	imes C + 32.$$

Accepted Answer

$$93.2\ ^\circ\mathrm{F}$$

Question 9

How many calories are obtained from a pat of butter if it provides 150 J of energy when metabolized? (Use $$1\ \mathrm{cal} = 4.184\ \mathrm{J})$$

Accepted Answer

36 cal

Question 10

Which of the following best describes the energy transformation when water at the top of a dam is released and flows downward?

Accepted Answer

Potential energy is converted to kinetic energy.

Question 11

How many joules are needed to melt 32.0 g of ice at $$0\ ^\circ\mathrm{C}$$? (The heat of fusion for water is $$334\ \mathrm{J/g}.)$$

Accepted Answer

$$10,700\ \mathrm{J}$$

Question 12

A volcano releases 175 g of steam at $$100\ ^\circ\mathrm{C}$$, which then condenses and freezes at $$0\ ^\circ\mathrm{C}. If $$the heat of vaporization is $$2260\ \mathrm{J/g}$$ and the heat of fusion is $$334\ \mathrm{J/g}$$, how many kilojoules are lost in total?

Accepted Answer

528 kJ

Question 13

Which of the following best explains why sand in the desert is hot during the day and cool at night?

Accepted Answer

Sand has a low specific heat, so it heats and cools quickly.

Question 14

Which process is used to prepare freeze-dried foods for long-term storage, and what change of state does it involve?

Accepted Answer

Sublimation; solid to gas

Question 15

A plateau (horizontal line) on a heating curve represents which of the following?

Accepted Answer

A constant temperature and a change of state

Question 16

Which of the following is a physical property of copper?

Accepted Answer

It is an excellent conductor of heat and electricity.

Question 17

Which of the following statements about mixtures is correct?

Accepted Answer

Mixtures can be separated by physical methods.

Question 18

A patient’s normal body temperature is $$37.0\ ^\circ\mathrm{C}. $$What is this temperature in kelvins? (Use $$K = ^\circ\mathrm{C} + 273.)$$

Accepted Answer

310 K

Question 19

Which of the following is an example of a physical change?

Accepted Answer

Ice cream melting

Question 20

Which of the following best describes the energy transfer when ocean water cools?

Accepted Answer

The surrounding air warms as the ocean water cools.

Matter and Energy: Classification, Properties, and Changes

Guida di studio - Domande di pratica

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