Section 11.3- Alkaline Earth Metals

Question 1

are never found naturally as free elements but occur only as 2+ ions in compounds

Answer 1

alkaline earth metals

Question 2

alkaline earth metals are found

Answer 2

in the crust of the earth

Question 3

_______________ and ______________ are common as silicate ores

Answer 3

beryllium and magneisum

Question 4

ionization energies of alkaline earth metals are stil, making them ___________ reactive

Answer 4

quite

Question 5

in some places, the groundwater is considered ______________ because of the presence of calcium ions

Answer 5

hard water

Question 6

deposits inside boilers, hot water heaters, and teapots are often due to CaCO3 and are known as

Answer 6

boiler scale

Question 7

water containing calcium or magnesium bicarbonates is called _____________________ since the hardness can be removed

Answer 7

temporary hard water

Question 8

water containing sulfates of calcium or magnesium cannot be softened by being boiled and is termed

Answer 8

permanent hard water

Question 9

water may best be softened by synthetic organic materials called

Answer 9

ion-exchange resins

Question 10

consist of large molecules (polymers) that form a network and that contain chemically bonded, negatively charged groups such as sulfonate
(-SO3 -)

Answer 10

cation-exchange resins

Question 11

the negative charge is usually balanced by

Answer 11

sodium or hydrogen ions

Question 12

contains positively charged groups such as -NR3 -

balanced by the OH- ions

Answer 12

anion-exchange resins

Question 13

all the alkaline earth metals but ___________ are prepared by the electrolysis of the molten chloride at high temperature

(i.e. CaCl2 ————–> Ca +Cl2)

Answer 13

beryllium

Question 14

due to its ability to transmit x-rays without absorbing them, _______ metal is used for the window in x-ray tubes

Answer 14

beryllium

Question 15

alkaline earth metal that burns in air with a brilliant white flame

Answer 15

magnesium

Question 16

more important than the free alkaline earth metals are their

Answer 16

compounds

Question 17

an essential component of bones and teeth, but it is also involved in nerve excitation, vision, and muscle contraction

Answer 17

calcium ion (Ca 2+)

Question 18

calcium compound that is one of the most heavily used chemicals in the US

Answer 18

calcium oxide (lime or quicklime)

Question 19

calcium oxide reacted with water becomes

Answer 19

slaked lime
Ca(OH)2

Question 20

calcium compound that is used extensively in iron ore reduction and in cement manufacture

Answer 20

calcium carbonate (limestone)

Question 21

pebble-sized lumps of calcium silicates and aluminates that are produced in the Portland cement preparation process

Answer 21

clinker

Question 22

cement is added to water, sand, and aggregate to form

Answer 22

concrete

Question 23

crushed rock or gravel added to prevent excessive shrinkage and to give strength

Answer 23

aggregate

Question 24

contrary to popular belief, cement and concrete do not harden by drying out; rather, the setting and hardening process involves chemical reactions of the cement compounds with water known as

Answer 24

hydration reactions

Question 25

a suspension of magnesium hydroxide, known as ____________________, is used as a stomach antacid and laxative

Answer 25

milk of magnesia

Question 26

the hydrate of ____________________ also known as Epsom salt is used in hot baths to reduce swelling from bruises or sprains

Answer 26

magnesium sulfate

Question 27

though most barium compounds are toxic, _________________________ is not poisonous because of its very low solubility

Answer 27

barium sulfate

Question 28

major commercial uses of the alkaline earth metal beryllium

Answer 28

strong, lightweight, corrosion-resistant alloys;
x-ray tube windows

Question 29

major commercial uses of the alkaline earth metal magnesium

Answer 29

1. alloys for airplanes, high-performance car, ladders, patio furniture, flashbulbs
2. pyrotechnics
3. incendiary bombs
4. refractory brick
5. milk of magnesia
6. Epsom salts

Question 30

major commercial uses of the alkaline earth metal calcium

Answer 30

1. lime and slaked lime widely used as bases in the chemical industry
2. cements
3. limestone used in iron ore reduction, cement production, and pollution control

Question 31

major commercial uses of the alkaline earth metal strontium

Answer 31

1. salts used in pyrotechnics to give a red flame

Question 32

major commercial uses of the alkaline earth metal barium

Answer 32

1. medicine (gastrointestinal x-rays)
2. white paints
3. used in pyrotechnics to give a green flame