Textbook Questions #27

Which statements about the process of electrolysis of water are true?

1. An electric current splits water into hydrogen and oxygen 2. Twice as much hydrogen gas forms because water is composed of two parts hydrogen and one part oxygen 3. Energy is added in the form of an electric current so that the reaction will occur

Which terms refer to physical changes?

1. Breaking 2. Freezing 3. Boiling

A process that involves one or more substances changing into new substances is called a(n) _____ change, but is also known as a(n) ___ ____.

1. Chemical 2. Chemical 3. Reaction

A change in properties must always accompany a(n) ____ ____.

1. Chemical 2. Reaction

Which techniques are used to separate mixtures?

1. Chromatography 2. Filtration 3. Distillation

A pure substance is matter that has a uniform and unchanging ____. Matter that is made up of two or more substances is a(n) ____.

1. Composition 2. Mixture

Which of these terms generally refer to chemical changes?

1. Explode 2. Corrode 3. Ferment 4. Decompose

Which terms refer to a phase change in matter?

1. Freeze 2. Condense 3. Vaporize 4. Boil

The law of conservation of mass states that mass is neither _____ nor ____ during a chemical reaction

1. Gained 2. Lost

Which statements about Antoine Lavoisier's experiments are true?

1. He carried out his reactions in a sealed container so the gas produced could not escape. 2. He studied the decomposition of mercury(II) oxide into mercury and oxygen. 3. He found that the mass before and after the reactions he studied did not change.

Mixtures that always have a single phase are ____ mixtures, while mixtures that have two or more distinct areas are ____ mixtured.

1. Homogenous 2. Heterogenous

Which of these are examples of chemical change?

1. Iron rusting 2. Food spoiling

Examples of extensive properties include ______.

1. Mass 2. Volume 3. Length

Which are true about chemical reactions, according to the law of conservation of mass?

1. Mass is neither created nor destroyed. 2. The total mass involved remains constant. 3. The mass of the products equals the mass of the reactants.

The periodic table organizes the elements into a grid or horizontal rows called _____ and vertical columns called ______.

1. Periods 2. Groups

The terms boil, freeze, condense, vaporize, and melt, but not the terms cut and break, generally refer to a ____ _____ in matter.

1. Phase 2. Change

A property that can be observed without changing the substance into another substance is a(n) _______ property. A property that usually requires changing the substance into another substance to be observed is a(n) ____ property.

1. Physical 2. Chemical

Because substances have uniform and unchanging compositions, they also have consistent ______ ______, such as density, that can be used to identify them.

1. Physical 2. Property

Which are the four states of matter found on Earth?

1. Plasma 2. Liquid 3. Solid 4. Gas

Four states of matter, including the state occurring in the form of lightning bolts, are the _____, ______, _____, and _____ states.

1. Solid 2. Liquid 3. Gas 4. Plasma

The physical forms in which all matter naturally exists on Earth are called the ______ of _____

1. States 2. Matter

Which statements about the organization of the periodic table are true?

1. The vertical columns on the periodic table are called groups or families. 2. The horizontal rows on the periodic table are called periods.

Which statements comparing pure substances and mixtures are true?

1. When pure substances combine in a mixture, they retain their chemical properties. 2. A mixture is a combination of two or more pure substances

The ability or inability of a substance to combine with or change into one or more other substances is called a _____ ____.

1. chemical 2. property

Which are physical properties of copper?

1. easily drawn into wires (ductile). 2. easily shaped into sheets (malleable). 3. reddish brown and shiny

On Earth, there are just over 90 naturally occurring _____. In contrast, there are more than 50 million known ____, and new ones are made or discovered at a rate of about 100,000 per year.

1. elements 2. compounds

According to estimates, about 75% of the mass of the universe is made up of _____, while a total of only about 20g of _____ is found dispersed throughout Earth's crust.

1. hydrogen 2. francium

A substance can often be identified by its ______, which do not depend on the amount of the substance present.

1. intensive properties

The chart that organizes all known elements into a grid of horizontal rows (periods) and vertical columns (groups or families) is called the _____ ______.

1. periodic 2. table

The formula for water, H2O, means that water is composed of ____ part(s) hydrogen (H) and ____ part (s) oxygen (O).

1. two 2. one

Which statements comparing physical and chemical properties are true?

1.Physical properties can be used to help identify the substance. 2. Physical properties can be observed without changing the substance into another substance. 3. Chemical properties can be used to help identify the substance.

Which statements about heterogeneous and homogeneous mixtures are true?

1.The existence of two or more distinct areas indicates a heterogeneous mixture. 2.Heterogeneous mixtures do not blend smoothly throughout. 3.Homogeneous mixtures have constant composition throughout the mixture 4.A homogeneous mixture always has a single phase.

Which statements about elements and compounds are true?

1.There are more than 50 million known compounds. 2.All known elements, naturally occurring and synthetic, are listed on the periodic table. 3. On Earth, over 90 elements occur naturally.

When 2 g of hydrogen and ____ g of oxygen react, they form 18g of water.

16

A solid-solid solution system made up of two or more metals is called a(n) _______.

Alloy

A technique that separates the components of a mixture dissolved in a gas or a liquid based on the ability of each component to travel or to be drawn across the surface of a fixed substrate is called _______

Chromatography

Which is a pure substance made up of two or more different elements that are combined chemically?

Compound

A separation technique that results in the formation of pure solid particles of a substance from a solution containing the dissolved substance is called _____

Crystallization

Examples of intensive properties include ______.

Density Melting Point Odor Color

Which is a physical separation technique that is based on differences in the boiling points of the substances involved?

Distillation

A pure substance that cannot be separated into simpler substances by physical or chemical means is a(n)

Element

According to the law of conservation of mass, the mass of the reactants in a chemical reaction ____ the mass of the products.

Equal

Physical properties that are dependent on the amount of substance present are called _____ properties

Extensive

Which are physical properties that are dependent on the amount of substance present?

Extensive Properties

True or false: The physical properties of a substance are of no value in identifying the substance.

False

Match the separation technique at left with its description at right.

Filtration: suitable for separating heterogeneous mixtures containing solids and liquids Distillation: points separates substances based on their boiling points. Crystallization: solid results in the formation of highly pure solids from a solution containing the dissolved solid

Which is a common form of matter that conforms to the shape of its container and fills the entire volume?

Gas

Match each type of matter, at left, with an example of that type, at right. The chart shows how the types of matter are organized.

Heterogeneous mixture: milk Homogenous mixture: steel element: iron compound: baking soda

A mixture that has constant composition throughout and always has a single phase is a _____ mixture.

Homogenous

Match each element, at left, with the correct description of its abundance, at right.

Hydrogen: about 75% of the mass of the universe. Oxygen and silicon: almost 75% of the mass of Earth's crust. Oxygen, carbon, and hydrogenL more than 90% of the human body. Francium: less than 20g in Earth's crust

If a substance can be identified by a single property, the property is best classified as a(n) _____ property

Intensive

Physical properties that are independent of the amount of substance present are called _____ properties.

Intensive

Which are physical properties that are independent of the amount of substance present?

Intensive properties

The formula for sodium chloride is NaCl. What does the formula show about the composition of the compound?

It is one part sodium (Na) and one part chlorine (Cl).

A form of matter that flows, has constant volume, and takes the shape of its container is a(n) _____

Liquid

Which is a form of matter that flows, has constant volume, and takes the shape of its container?

Liquid

Which is a change that alters a substance without changing its composition?

Physical change

Which is a characteristic of matter that can be observed or measured without changing the sample's composition?

Physical property

A form of matter that has its own definite shape and volume is a(n) _____

Solid

When matter has its own definite shape it is a(n) ______

Solid

Which is a form of matter that has its own definite shape and volume?

Solid

Match each state of matter at left with its description at right.

Solid: has its own definite shape and volume Liquid: Flows, has constant volume, and takes the shape of its container Gas: Takes the shape and full volume of its container

Another term for a homogeneous mixture is a(n) _____

Solution

All matter that exists on Earth exists in a physical form such as solid, liquid, or gas. These are known as ______.

States of Matter

Which is a process during which a solid changes to vapor without melting, which can be used to separate certain mixtures?

Sublimation

The gaseous state of a substance that is a solid or liquid at room temperature is called a(n) _____

Vapor

Which is the gaseous state of a substance that is a solid or a liquid at room temperature?

Vapor

French scientist Antoine Lavoisier was one of the first to use an analytical ______ to monitor chemical reactions.

balance

Rusting and the spoilage of food are two examples of _____ change

chemical

The terms decompose, explode, rust, oxidize, corrode, tarnish, ferment, burn, and rot generally refer to _____ changes

chemical

It is important to state the specific conditions (e.g., temperature and pressure) under which observations of a substance are made because ______.

chemical and physical properties can vary depending on these conditions

Ice floats on water and warm water rises because the property of ______ differs or water at different temperatures and in different states of matter.

density

Compared with the properties of the elements that make it up, the properties of a compound are ______.

different

The properties of a compound are ____ from those of its component elements.

different

The process shown here is called _____.

electrolysis

A separation technique that uses a porous barrier to separate a solid from a liquid is called _____.

filtration

Match each solution system at left with the correct example at right

gas-gas: breathable air gas-liquid: oxygen and carbon dioxide in seawater solid-liquid: salts dissolved in seawater solid-solid: an alloy made of two or more metals

Match each temperature at left with the description of water at standard pressure that is appropriate for that temperature.

greater than 100 C: a gas that reacts rapidly with many different substances. between 0 C and 100 C: a liquid with a density of about 1.0 g/cm^3 and is not particularly reactive. below 0 C: a solid with a density of about 0.92 g/cm^3

Which is a mixture that does not blend smoothly throughout and in which the individual substances remain distinct?

heterogeneous mixture

A mixture that does not blend smoothly throughout and in which the individual substances remain distinct is called a(n) ____ micture.

heterogenous

Sodium chloride, or table salt, is an example of a substance because ______.

its composition and properties do not change from one sample to another.

In a chemical reaction, mass is neither created nor destroyed, according to the ______.

law of conservation of mass

A combination of two or more pure substances in which each pure substance retains its individual chemical properties is a(n) ______.

mixture

Which is the chart that organizes the elements into a grid of rows (periods) and columns (groups or families)?

periodic table of the elements

A transition of matter from one state to another is a(n) _____ change

phase

A change that alters a substance without changing its composition is a(n) _____ change

physical

Cutting paper, crumpling foil, and boiling water are all examples of _____ changes

physical

A chemical reaction always produces a change in ______.

properties

Which is a chemical property of copper?

reacts with sulfric acid

All homogeneous mixtures can also be called ______.

solutions

Matter with a uniform and unchanging composition is called a(n) ______

substance