Q: A pool is a cylinder with a diameter of $$10.3\ \mathrm{m}$$ and a depth of $$2.00\ \mathrm{m}. $$What is its volume in $$\mathrm{cm}^3$$? (Use $$V = h \times 3.14 \times r^2$, 1$$\ \mathrm{m} = 100\ \mathrm{cm}$$)

$$1.67 \times 10^8$\ \mathrm{cm}^3$$

Q: Which of the following is the correct calculation for the average atomic mass of silicon given the following isotopic abundances: $$92.23\% Si-28$$ ($$27.977\ \mathrm{amu}$$), $$4.67\% Si-29$$ ($$28.977\ \mathrm{amu}$$), $$3.10\% Si-30$$ ($$29.974\ \mathrm{amu}$$)?

$$(0.9223 \times 27.977) + (0.0467 \times 28.977) + (0.0310 \times 29.974) = 28.09\ \mathrm{amu}$$

Question 1

Which of the following best describes why the mass of ashes after burning wood is less than the original mass of the wood?

Accepted Answer

The missing mass was converted into gaseous compounds and released into the air.

Question 2

A student measures the temperature outside as $$-12\ ^\circ\mathrm{F}. $$What is this temperature in Kelvin? Use the equations: $$^\circ\mathrm{F} = 1.8 	imes ^\circ\mathrm{C} + 32$$ and $$K = ^\circ\mathrm{C} + 273.$$

Accepted Answer

$$249\ \mathrm{K}$$

Question 3

A block has dimensions $$2.2\ \mathrm{cm} 	imes 3.0\ \mathrm{cm} 	imes 1.5\ \mathrm{cm}$$ and a mass of $$12.4\ \mathrm{g}. $$Will it float in water? (Density of water $$= 1.0\ \mathrm{g/mL})$$

Accepted Answer

No, because its density is $$1.3\ \mathrm{g/mL}$$, which is greater than water.

Question 4

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

Accepted Answer

Melting gold to form jewelry.

Question 5

A sample of water is heated from $$25.0\ ^\circ\mathrm{C} to$$ $$50.0\ ^\circ\mathrm{C}. If $$the mass is $$100.0\ \mathrm{g}$$ and the specific heat is $$4.184\ \mathrm{J/g\ ^\circ C}$$, how much heat (in kJ) is required? Use $$q = m 	imes c 	imes \Delta T.$$

Accepted Answer

$$10.5\ \mathrm{kJ}$$

Question 6

Which of the following statements about isotopes is correct?

Accepted Answer

Isotopes have the same number of protons but different numbers of neutrons.

Question 7

A nugget of gold with a mass of $$521\ \mathrm{g} is $$added to $$50.0\ \mathrm{mL} of $$water, causing the water level to rise to $$77.0\ \mathrm{mL}. $$What is the density of gold in $$\mathrm{g/mL}$$?

Accepted Answer

$$19.3\ \mathrm{g/mL}$$

Question 8

Which of the following is NOT a property of alkali metals (Group 1A)?

Accepted Answer

Most are liquids at room temperature.

Question 9

Which of the following best describes the scientific method?

Accepted Answer

It emphasizes observation and experimentation as the way to understand the world.

Question 10

A compound can be separated into its elements by which of the following?

Accepted Answer

Chemical processes

Question 11

Which of the following best explains why water requires more energy to heat than aluminum for the same mass and temperature change?

Accepted Answer

Water has a larger specific heat than aluminum.

Question 12

Which of the following is the correct scientific notation for $$0.00050210$$?

Accepted Answer

$$5.0210 	imes 10$$^{-4}$$

Question 13

Which of the following elements is a metalloid?

Accepted Answer

Silicon

Question 14

A pool is a cylinder with a diameter of $$10.3\ \mathrm{m}$$ and a depth of $$2.00\ \mathrm{m}. $$What is its volume in $$\mathrm{cm}^3$$? (Use $$V = h 	imes 3.14 	imes r^2$, 1$$\ \mathrm{m} = 100\ \mathrm{cm}$$)

Accepted Answer

$$1.67 	imes 10^8$\ \mathrm{cm}^3$$

Question 15

Which of the following is a characteristic property of nonmetals such as sulfur?

Accepted Answer

Dull and a good insulator

Question 16

Which of the following best describes the energy of steam at $$110\ ^\circ\mathrm{C}$$ compared to water at $$20\ ^\circ\mathrm{C}$$?

Accepted Answer

The particles in steam move more rapidly due to higher kinetic energy.

Question 17

Which of the following is the correct calculation for the average atomic mass of silicon given the following isotopic abundances: $$92.23\% Si-28$$ ($$27.977\ \mathrm{amu}$$), $$4.67\% Si-29$$ ($$28.977\ \mathrm{amu}$$), $$3.10\% Si-30$$ ($$29.974\ \mathrm{amu}$$)?

Accepted Answer

$$(0.9223 	imes 27.977) + (0.0467 	imes 28.977) + (0.0310 	imes 29.974) = 28.09\ \mathrm{amu}$$

Question 18

Which of the following is the best definition of energy?

Accepted Answer

The ability to do work

Question 19

Which of the following statements about the atomic theory is correct?

Accepted Answer

Atoms of the same or different elements combine to form compounds.

Intro to Chemistry Exam 1 – Step-by-Step Study Guidance (Chapters 1–4)

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