Section 10.6- Halogens

Question 1

all _____________ are too reactive to be found naturally in their free state

Answer 1

halogens (chlorine, bromine, iodine)

Question 2

the most reactive of the nonmetallic elements

Answer 2

halogens

Question 3

the most reactive of any element

Answer 3

fluorine

Question 4

a greenish-yellow GAS that is denser than air and has a choking and irritating odor

Answer 4

chlorine

Question 5

a dark red-brown LIQUID that has a choking and irritating odor

Answer 5

bromine

Question 6

a dark gray SOLID with a slight metallic lister and little odor; when heated, it passes directly into a gaseous state

Answer 6

iodine

Question 7

means passing directly into a gaseous state

Answer 7

sublimes

Question 8

fluorine is usually prepared by

Answer 8

electrolysis of molten salts

Question 9

chlorine is prepared commercially by

Answer 9

electrolysis of either brine or molten rock salt

Question 10

are often produced commercially by bubbling Cl2 through seawater or brine

Answer 10

bromine and iodine

Question 11

may be prepared from sodium iodate ore

Answer 11

elmental iodine

Question 12

the halides except for ____________ may be prepared from their alkali metal halide salts by heating them with concentrated H2SO4 and MnO2

Answer 12

except fluoride

Question 13

one well-known use of the element _____________ is the in drinking water and in toothpaste as an anticavity ingredient

Answer 13

fluoride

Question 14

fluoridation is useful because tooth enamel is composed of an insoluble phosphate known as

Answer 14

hydroxyapatite

Question 15

harder and much more decay resistant than hydroxyapatite and is less affected by acids in the mouth

Answer 15

fluorapatite

Question 16

a major use of __________ is the manufacture of refrigerants,

Answer 16

fluorine

Question 17

special chemicals used in air conditioners, refrigerators, freezers, and heat pumps to remove heat from the substance to be cooled

Answer 17

refrigerants

Question 18

until the 1990s, the most widely used refrigerants were the _____________, a group of compounds containing carbon, fluoride, and chlorine

Answer 18

Freons

Question 19

two of the most common Freons

Answer 19

Freon-12= AUTOMOBILE air conditioners and refrigerators
Freon-21= household and commercial air conditioners

Question 20

Freons and related compounds were banned in the early 1990s by the ___________ after they were accused of harming the earth’s ozone layer

Answer 20

Montreal Protocol

Question 21

Freon-substitute R- 134a was restricted by the 1997 ______________ on “global warming”

Answer 21

Kyoto Protocol

Question 22

important use of fluorine is in the manufacture of _____________________, used for chemically inert and nonstick properties in electrical insulators, high-temperature plastics, cookware, nonlubricated valves and bearings, etc.

Answer 22

polytetrafluoroethylene (PTFE)

Question 23

some of the most interesting fluorine compounds are the ________________, organic compounds having their hydrogen atoms replaced with fluorine atoms

Answer 23

perfluorocarbons

Question 24

one example of perfluorocarbons is a __________________

Answer 24

perflubron

Question 25

technique using perflubron to save the lives of very premature infants whose lungs are not yet developed enough to breath air; this technique may also be used to treat victims of smoke inhalation, near drowning, or acute respiratory distress

Answer 25

partial liquid ventilation

Question 26

can slowly dissolve glass and is often used to frost light bulbs and to etch designs in glass surfaces

Answer 26

hydrogen fluoride

Question 27

one of the most versatile, common elements in the periodic table

Answer 27

chlorine

Question 28

household bleach is a 5% solution of sodium hypochlorite in which the active ingredient is the

Answer 28

hypochlorite ion

Question 29

swimming pools are kept clear by the addition of chemicals that produce

Answer 29

hypochlorous acid

Question 30

one of the most important and widely use chlorine compounds is a durable, chemically inert plastic manufactured from petroleum and rock salt

Answer 30

PVC

Question 31

most _______________ either contain chlorine or are manufactured by using chlorine 85% involve chlorine in some way

Answer 31

medicines

Question 32

uses of chlorine

Answer 32

1. Bleaches and disinfectant 2. PVC 3. Medicines 4. Crop-protection 5. Banned and restricted chlorine compounds

Question 33

banned insecticide which saved millions of lives from malaria until the United States sharply curtailed the worldwide use

Answer 33

DDT

Question 34

nonflammable banned chlorinated compound that have been used extensively in transformers and capacitors on electric power lines because of their chemical stability, low volatility, and ability to conduct heat and not electricity

Answer 34

PCB

Question 35

the use of ________ compounds has declined in recent years as a result of several circumstances

Answer 35

bromine

Question 36

bromide compounds that was an important agricultural fumigant in the mid-1990s until the Montreal Protocol mandated that its used be phased out in industrialized nations

Answer 36

methyl bromide

Question 37

an important use of bromine was in the synthesis of _________ firefighting chemicals that can interfere with the chemical reactions that cause combustion

Answer 37

halons

Question 38

uses of bromine

Answer 38

1. methyl bromide 2. HALONS- stop combustion 3. silver bromide- photograph 4. hypobromous acid- disinfect water

Question 39

uses of iodine

Answer 39

1. tincture of iodine- antiseptic for wounds 2. hormone thyroxine contains iodine 3. lack of iodine causes goiters

Question 40

an alcohol solution of iodine that is used for its antiseptic action on cuts or scrapes

Answer 40

tincture of iodine