MIXTURES Reviewer 3

Section 15.4 Heterogeneous Mixtures Practice Test

	1.	A suspension is _________.

		a.	a heterogeneous mixture
		b.	a homogeneous mixture
		c.	a solution
		d.	impossible to prepare

	2.	A colloid contains particles that ____________________.

		a.	are smaller than atoms
		b.	are between 1 nm and 1000 nm in diameter
		c.	settle out if left undisturbed
		d.	are atomic-size in scale

	3.	The Tyndall effect describes ______________.

		a.	precipitation of colloidal particles using electrically charged plates
		b.	the adsorption of positive ions onto the surface of a hydrophilic solid
		c.	hydrophobic interactions between nonpolar molecules
		d.	the scattering of light by colloidal particles

	4.	Which one of the following is an example of an emulsion?

		a.	shaving cream
		b.	fog
		c.	mayonnaise
		d.	styrofoam

Answers: a b d c

SOLUTION CONCENTRATION

1. How many grams of NaCl are dissolved in 500.0 mL of a 0.05M solution of NaCl?

		a.	0.05 g
		b.	0.29 g
		c.	1.46 g
		d.	2.92 g
	Hint

	2.	A solution that contains less solute per volume of solvent than another solution made from the same components is said to be more ________.

		a.	dilute
		b.	concentrated
		c.	solvated
		d.	dissolved
	Hint

	3.	Molarity is defined as the ____________.

		a.	mass of solute per mass of solution
		b.	volume of solute per volume of solution
		c.	moles of solute per liter of solution
		d.	moles of solute per kilograms of solvent
	Hint

	4.	What volume of 12.6M HCl must be added to sufficient water to prepare 5.00 liters of 3.00M HCl?

		a.	1.19 L
		b.	21.0 L
		c.	0.840 L
		d.	7.56 L
	Hint

	5.	What mass of Ca(OH)2 is contained in 1500 mL of 0.0250M Ca(OH)2 solution?

		a.	3.17 g
		b.	2.78 g
		c.	1.85 g
		d.	2.34 g
	Hint

	6.	Calculate the molality of a solution that contains 25 g of H2SO4 dissolved in 80 g of water.

		a.	1.6m
		b.	2.2m
		c.	3.2m
		d.	6.3m
	Hint

	7.	Calculate the molality of 10% H3PO4 solution in water.

		a.	0.380m
		b.	0.760m
		c.	1.13m
		d.	1.51m
	Hint

	8.	What is the mole fraction of ethanol (C2H5OH) in a solution of 47.5 g of ethanol in 850 g of water?

		a.	0.021
		b.	0.18
		c.	0.032
		d.	0.98
	Hint

	9.	What is the molarity of 2500 mL of a solution that contains 160 grams of ammonium nitrate (NH4NO3)?

		a.	0.333M
		b.	0.450M
		c.	0.600M
		d.	0.800M

Answers: c a c a b c c a d

SOLUTIONS

Section 15.1 What are Solutions?

Practice Test

	1.	If 12.0 g of a gas at 2.5 atm dissolve in 1.0 L of water at 25°C, how much will dissolve in 1.0 L of water at STP?

		a.	0.21 g/L
		b.	2.1 g/L
		c.	4.8 g/L
		d.	12.0 g/L

	2.	In a solution, the substance that does the dissolving is ____________.

		a.	the solvent
		b.	the solute
		c.	saturated
		d.	miscible

	3.	Solutions can be mixtures of _______________.

		a.	solids
		b.	liquids
		c.	gases
		d.	all of the above

	4.	In a glass of sugar water, which substance is the solute?

		a.	water
		b.	sugar
		c.	glass
		d.	none of the above

	5.	The process of a solvent and a solute completely mixing and forming a solution is ________.

		a.	solvation
		b.	salvation
		c.	crystallization
		d.	ionization

	6.	Which of the following will not increase the rate of solvation?

		a.	agitating the mixture
		b.	increasing the surface area
		c.	increasing the temperature
		d.	formation of a precipitate

	7.	A solution is said to be ________ when more solute can be dissolved in the solvent at a given temperature.

		a.	supersaturated
		b.	saturated
		c.	unsaturated
		d.	solvated

	8.	What is a common means of identifying a supersaturated solution?

		a.	precipitation
		b.	dissolution
		c.	solvation
		d.	hydration

NUCLEAR FUSION AND FISSION Reviwer 4

Section 25.4 Fission and Fusion of Atomic Nuclei Practice Test

	1.	If one fission reaction of a uranium-235 atom produced two neutrons, how many neutrons would be released if the chain reaction occurred three more times?

		a.	2
		b.	4
		c.	8
		d.	16

	2.	To hold the nucleons together in the nucleus, energy is required. What is the name of this energy?

		a.	binding energy
		b.	kinetic energy
		c.	thermal energy
		d.	free energy

	3.	What is the name of the process in which a large radioactive isotope is broken into smaller isotopes?

		a.	transmutation
		b.	nuclear fission
		c.	nuclear fusion
		d.	beta emission

	4.	What is the name given to the amount of a radioactive substance that is massive enough to sustain a chain reaction?

		a.	critical mass
		b.	critical condition
		c.	mole
		d.	mass defect

	5.	In a nuclear reactor, what is the heat generated by the nuclear fission reaction used for?

		a.	fusing other unstable isotopes together
		b.	generating steam
		c.	freezing water
		d.	making building products

	6.	The energy produced by the Sun is a result of ___________.

		a.	nuclear fission
		b.	alpha emission
		c.	nuclear fusion
		d.	radiocarbon dating

	7.	The reaction products of nuclear fusion are __________ than the reactants.

		a.	more massive
		b.	less massive
		c.	less radioactive
		d.	cooler

	8.	What is the major problem associated with the development of fusion as a controlled energy source?

		a.	The containment of the radioactive decay products.
		b.	The low energy yield of the fuel.
		c.	The containment of the extremely high-temperature plasma.
		d.	The resulting air pollution.

NUCLEAR CHEMISTRY Exercise 3

Section 25.3 Transmutation Practice Test

	1.	The half-life for tritium is 12.32 years. How long will it take for a 10.00-g sample of tritium to decay until 1.875 g remain? Data Table 1 Parent and daughter nuclei data Number of half-lives Parent fraction Daughter fraction Daughter-to-parent ratio 0 1     1 1/2     2 1/4     3 1/8     4 1/16

		a.	0.6594 years
		b.	5.333 years
		c.	24.64 years
		d.	30.80 years

	2.	The conversion of an atom of one element into an atom of a different element is _______________.

		a.	isotopic abundance
		b.	radioactivity
		c.	transuranium element
		d.	transmutation

	3.	The elements with atomic numbers greater than 92 are _______________.

		a.	transuranium elements
		b.	lanthanides
		c.	actinides
		d.	halogens

	4.	The goal of ancient alchemy was to change lead (atomic number 82) into gold (atomic number 79). Which of the following could result in the transformation of lead into gold?

		a.	an induced transmutation that removes an alpha particle and a positron from a lead atom
		b.	an induced transmutation that adds an alpha particle and removes a positron from a lead atom
		c.	an induced transmutation that removes an alpha particle and a beta particle from a lead atom
		d.	an induced transmutation that adds an alpha particle and removes a beta particle from a lead atom

	5.	The time required for one-half of a radioactive isotope to decay into its products is _______________.

		a.	half-time
		b.	half-life
		c.	transmutation
		d.	isomerization

	6.	Carbon-14 is used to date archaeological artifacts. If carbon-14 decays by loss of a beta particle, what new element is formed?

		a.	nitrogen-13
		b.	nitrogen-14
		c.	carbon-13
		d.	boron-14

RADIOACTIVE DECAY Exercise 2

Section 25.2 Radioactive Decay Practice Test

	1.	If a thorium-230 atom undergoes alpha decay, what are the products of the reaction?

		a.	actinium and an alpha particle
		b.	actinium and a positron
		c.	radium and an alpha particle
		d.	radium and a positron

	2.	What ratio is used to evaluate the stability of a nucleus?

		a.	the electron to proton ratio
		b.	the neutron to proton ratio
		c.	the electron to neutron ratio
		d.	the atomic number to mass number ratio

	3.	What conditions in the nucleus usually result in beta decay?

		a.	The nucleus has too many neutrons.
		b.	The nucleus has too many protons.
		c.	The valence electrons are lost.
		d.	The atomic mass is greater than 300 amu.

	4.	What happens during positron emission?

		a.	A proton is converted into a neutron and a positron.
		b.	A neutron is converted into a proton and a positron.
		c.	A proton is converted into a neutron and an electron.
		d.	An atomic explosion occurs.

	5.	What happens to the mass of an atom when it undergoes alpha decay?

		a.	There is no change in mass.
		b.	The mass decreases by 1.
		c.	The mass increases by 4.
		d.	The mass decreases by 4.