Question 1

What structural unit is characteristic of quartz and most silicates?

Accepted Answer

The tetrahedral structure, consisting of a silicon atom surrounded by four oxygen atoms, is characteristic of quartz and most silicates.

Question 2

Which of the following does not apply to silicates?

Accepted Answer

Silicates are compounds that contain silicon and oxygen as their primary constituents. They are some of the most abundant minerals on the earth, making up the majority of the earth's crust. Silicates do not contain carbon as a primary constituent. Choice A is correct because clay is a type of silicate mineral. Choice B is correct because silicates often contain tetrahedral units of SiO4. Choice D is incorrect because SiO₂ is not a valid chemical formula for any known silicate mineral.

Question 3

In the reduction of iron in a blast furnace, calcium carbonate, from limestone, is added to combine with what impurity in the iron ore?

Accepted Answer

Calcium carbonate is added to the blast furnace to remove silicon dioxide (SiO2) as an impurity. When calcium carbonate decomposes, it forms calcium oxide (lime), which then reacts with silicon dioxide to form calcium silicate, a slag that can be easily removed.

Question 4

The chloralkali process uses electrolysis of aqueous sodium chloride to produce all but which one of the following?

Accepted Answer

The chloralkali process produces chlorine gas (Cl2), sodium hydroxide (NaOH), and hydrogen gas (H2), but does not produce carbon monoxide (CO). Therefore, option D is the correct answer.

Question 5

Which form of iron contains the least amount of carbon?

Accepted Answer

Steel contains the least amount of carbon compared to pig iron and cast iron, typically less than 2%.

Question 6

Which kind of rocks are formed by solidification of molten rock?

Accepted Answer

Rocks formed by the solidification of molten rock are called igneous rocks.

Question 7

The process by which copper is prepared from its ores is

Accepted Answer

The answer of The process by which copper is prepared...

Question 8

Pyrex and Kimax glass typically contain an oxide of which element that gives the glass a small coefficient of thermal expansion?

Accepted Answer

Pyrex and Kimax glass contain boron oxide which gives them a small coefficient of thermal expansion. This means that the glass can resist sudden changes in temperature without cracking or breaking. Sodium and lead are not typically used in these types of glass, and arsenic is not commonly used in glass manufacturing due to its toxicity.

Question 9

The most abundant substances in rocks are

Accepted Answer

Silicates are the most abundant substances in rocks, making up approximately 90% of the Earth's crust. Carbonates and oxides are also common in rocks, but not as abundant as silicates. Sulfates are relatively rare in rocks.

Question 10

Which of the following elements comprises more the 25% of both the Earth's crust and the whole Earth?

Accepted Answer

Oxygen is the most abundant element in the Earth's crust and makes up 46.6% of the crust by weight. It is also one of the most abundant elements in the Earth's entire mass, making up about 30% of the total. None of the other options (hydrogen, iron, aluminum) make up more than 5% of either the crust or the whole Earth.

Question 11

Which of the following is the most abundant metal in the Earth's crust?

Accepted Answer

Aluminum (Al) is the most abundant metal in the Earth's crust, making up approximately 8% of the crust by weight. Magnesium (Mg), iron (Fe), and nickel (Ni) are also common in the crust, but they are less abundant than aluminum.

Question 12

Which metal is sufficiently concentrated in the oceans so that it is currently extracted commercially?

Accepted Answer

Magnesium is sufficiently concentrated in the oceans so that it is currently extracted commercially using a process called electrolysis. The other metals listed may also be present in seawater but are not typically economically viable to extract on a large scale.

Question 13

Which mineral is likely to be used in cement and wallboard?

Accepted Answer

Sulfate minerals such as gypsum (calcium sulfate) are commonly used in the production of cement and wallboard.

Question 14

Which substance is formed when silica is melted (so that SiO₄ units are reorganized) and then cooled?

Accepted Answer

When silica is melted, the SiO4 tetrahedra reorganize and form a random network structure which solidifies into a non-crystalline solid called glass.

Question 15

Which of the following metals and ores is not a correct pair?

Accepted Answer

The correct chemical formula for gold is Au and it does not form an oxide with oxygen, so it is not paired with AuO.

Question 16

Over the years what element has been used as a reducing agent to reduce iron metal from its ores?

Accepted Answer

Carbon has been used as a reducing agent to extract iron from its ores in the form of coke (a type of carbon derived from coal). This carbon reduces the iron oxide into iron metal, along with the production of carbon dioxide gas. This method is known as the blast furnace process and has been the main method of iron production for centuries.

Question 17

Older glass beverage bottles were green due to the presence of which metal ion in the silica from which the bottle was made?

Accepted Answer

The green color in older glass beverage bottles is due to the presence of iron (Fe) ions in the silica used to make the bottles. Iron impurities can give glass a green or brownish color.

Question 18

Which of the following is not a property of ceramics?

Accepted Answer

Ceramics are generally known for their ability to withstand high temperatures and their hardness. They are also often brittle, and may fail in response to stress. However, they are not known for their conductivity, unlike metals or some types of polymers. Additionally, while the cost of raw materials for ceramics can vary, they are not typically considered to be made from cheap raw materials.

Question 19

Which of the following metals is recovered from sea water?

Accepted Answer

Magnesium is the metal that can be recovered from sea water. While iron and copper are widely used metals, they are mostly obtained from terrestrial sources such as mines. On the other hand, magnesium is present in large quantities in sea water and can be extracted through processes such as electrolysis.

Question 20

Which term or phrase does not apply to steel?

Accepted Answer

Steel typically has a low to medium carbon content, and high carbon steel is not as common.

Quiz 18: The Chemistry of Useful Materials