physical science chapter 2 review

A ceramic is an organic, metallic compound.

'False'.

When a product is called biodegradable, it means that the product will never break down.

'False'.

True or false: The following equation is balanced properly: 6CO2 + 6H2O → C6H12O6 + O2

'False'. should read: 6CO2 + 6H2O → C6H12O6 + 6 O2

If two molecules of hydrochloric acid (HCl) and one atom of magnesium (Mg) are the reactants of a single replacement reaction, how many magnesium atoms are in the product? 2HCI + Mg =

1 Mg atom

If two atoms of sodium (Na) combine with one molecule of chlorine (Cl2), which of the following could be the product?

2NaCl

In the formula, 3NO2, which number is the coefficient?

3

Iron reacts with oxygen to produce iron oxide (rust). This reaction is represented in an equation as 4Fe + xO2 → 2Fe2O3. Identify the value of x that will balance the equation.

3

If 56 grams of carbon monoxide burns in oxygen to produce 88 grams of carbon dioxide, the mass of oxygen involved in the reaction is:

32 grams

The chemical formula for artificial sweetener is C7H5NO3S. How many carbon atoms will be found in 5 molecules of the artificial sweetener.

35

The chemical formula for glucose is C6H12O6. Therefore, four molecules of glucose will have _____ number of hydrogen atoms.

48

Which coefficient of O2 is needed to balance the equation C3H8 + O2 → 3CO2 + 4H2O?

5

How many atoms of oxygen (O) are in the product for the double replacement reaction? Pb(NO3)2 + 2KI = Pbl2 + 2KNO3

6 oxygen

Which of these equations represents a single replacement reaction?

A + BC = AB + C

What needs to be added to balance the equation for the decomposition of mercury oxide (HgO)? 2Hgo = Hg +O2

A 2 should be in front of Hg.

Which of the following is a sign of a chemical change?

A leaf changing color from green to red

Which of the following is a sign of a chemical reaction?

Adding a grey iron nail to water turns the nail reddish-brown in a couple of weeks.

Methane is CH4. Which equation represents the combustion of methane?

CH4 + 2O2 → CO2 + 2H2O

A combustion reaction always has the same products: H2O and O2.

False

True or False. Temperature is a measure of the average potential energy of particles.

False (kinetic)

Which of these factors make hydrogen fuel cells a better option than burning fossil fuels?

Hydrogen fuel cells create less pollution.

Which of these are benefits of using a synthetic material? Select all that apply.

Synthetic materials are lightweight., Synthetic materials tend to be cheaper to produce., Synthetic materials are more fuel efficient.

A scientist compares two samples of white powder. One powder was present at the beginning of an experiment. The other powder was present at the end. She wants to determine whether a chemical reaction has occurred. She finds that neither sample bubbles or dissolves in water. She measures the mass and volume of the solids. Sample one has a volume of 45 cm3 and a mass of 0.5 g. Sample two has a volume of 65 cm3 and a mass of 1.3 g. What should the scientist conclude?

The densities of the samples are different, so a chemical reaction has occurred.

Which of the following suggests that a physical change has taken place in an ice cube?

The ice cube melts.

A bike rider does work to make it up to the top of a mountain. How could you use the law of conservation of energy to describe his trip down the mountain?

The rider uses energy to do work going up the mountain. This energy changes into kinetic energy on the way down.

Which statement is true for one molecule of sulfur trioxide?

There is one atom of sulfur and three atoms of oxygen.

Which two statements about plastics are true? Select all that apply.

They are made from oil and natural gas., They repel water.

Which three statements are true about all alloys? Select all that apply.

They're harder than the pure metals they're made of., They're good conductors of electricity., They have a metal as their main component.

An alloy is a blend of two or more components where at least one of them is metal.

True

The chemical formula for carbonic acid, a compound used in carbonated drinks, is H2CO3. If you were to draw the structural image of this chemical, the carbon atom would be in the middle.

True

True or false: This balanced equation shows the combustion of ethane: 2C2H6 + 7O2 → 4CO2 + 6H2O

True

Chopping wood is considered a physical change, while burning it is a chemical change.

True'.

Which of these are naturally occurring materials? Select all that apply.

Wood, Natural Gas, Cotton

You know that a chemical reaction has occurred when __________.

a broken egg stinks after it has been sitting out for several days

Which category of materials does concrete belong to?

a. ceramic composite.

Which of these are examples of mixing and separating? You may choose multiple answers.

a. removing seed casings from grains b. a soda bottle bubbling when it is opened

When designing a product what are manufacturers concerned with:

a.How the package will look to consumers b. How the product will perform c. How the product can be disposed of

When two compounds, NaOH and HCl combine, the OH- group from NaOH and the H+ from HCl combine to produce water. The chloride ion and sodium ion combine to make table salt as shown on your screen. What type of reaction is this?

acid-base neutralization reaction

Katrina inserts a key into her car's ignition. She turns the key, putting her car into ignition mode. In this mode, some energy is used to increase the temperature of the car's fuel. This energy allows the fuel to combust and the car to move. What's this energy called?

activation energy

Methane is a flammable compound made of carbon and hydrogen atoms. How could you separate the carbon and hydrogen in methane?

add a spark to ignite the methane because this will split the carbon and hydrogen atoms

Which of these is an example of a sustainable resource?

b. using solar power.

Which of these is an alloy of copper?

bronze

Which of the following describes the use of a nonrenewable energy source?

burning coal to create steam in power plants

What are the products in the following chemical reaction? methane + oxygen = carbon dioxide + water

carbon dioxide +water

When milk spoils, it smells bad. This is a sign of __________.

chemical change

Burning magnesium gives us magnesium oxide. This is an example of a ________ reaction. _______ is the common element involved with all chemical reactions of this kind.

combustion, oxygen

Michael uses a car that burns fossil fuels. What type of chemical reaction involved in this action?

combustion.

You place an empty pan directly on top of a stove burner, and turn on the burner. Soon, the temperature of the pan increases. How is heat transferred from the burner to the pan?

conduction

This chemical equation represents the burning of methane, but the equation is incomplete. What is the missing coefficient in both the reactants and the products? CH4 + ____O2 → CO2 + ____H2O

2

dentify the reactant(s) in this chemical equation. 2KCIO(sub3) = 2KCI + 30 (sub2)

2KClO3

What are three disadvantages of making and using plastic? Select all that apply.

It pollutes the land and water., It takes an incredibly long time to break down., It isn't easy to recycle.

Which category of materials does concrete belong to and why?

It's a composite because it's a mixture of cement, sand, and other granular pieces.

Which of the following is the best sign that cooking pancake batter causes a chemical change?

It's hard to turn cooked pancakes back into batter.

When you burn magnesium, what is the product?

Magnesium oxide.

Which of the following cannot be recycled?

Plastic toys.

Which two facts about plastic affect the environment in a negative way? Select all that apply.

Some plastics release toxic chemicals., They don't break down over time.

A scientist conducts a chemical reaction. At the beginning of the reaction, she combines 5.4 grams of the first reactant and 6.3 grams of the second reactant. She runs the reaction in a closed chamber and heats only the reaction. A small amount of gas is produced. What can you conclude about the total mass of the substances present when the reaction is complete?

The mass equals 11.7 grams because the system is closed.

You make ammonia (NH3) in a factory and a large order just arrived. To increase your rate of production, or the rate of the reaction to produce ammonia, you can __________.

add a catalyst to the reactants

All of the following are ceramics EXCEPT:

brass.

Which of the following could cause only a physical change in a hamburger patty?

cutting it in half

What does this chemical reaction describe? water → hydrogen + oxygen

decomposition

Which law represents a balanced chemical equation?

law of conservation of mass

If you take your used oil to a drop off site, you are:

recycling.

Iron oxide reacts with aluminum to give aluminum oxide and iron. What type of chemical reaction does this illustrate? iron oxide + aluminum = aluminum oxide + iron

replacement

If you paint old chairs to make them look new you are:

reusing.

All of the following are examples of chemical reactions EXCEPT:

rubbing to sticks together

Potassium chloride (KCl) and water form from the reaction of an acid and an alkali. Therefore, KCl is a ______.

salt

The chemical name for sand is silicon dioxide. The two elements found in a sample of this sand are

silicon and oxygen

You are making a new chemical, but the reaction rate is really slow. If you heat the reaction, it will most likely __________.

speed up

Classify each material as an alloy or a ceramic. Drag each label to the correct location. Alloy: Ceramic:

steel brass bronze brick tile glass

What kind of chemical reaction does the chemical equation: sodium + chlorine → sodium chloride represent?

synthesis

Which option shows a coefficient on the product side in this chemical equation? 3Fe + 4H2 O = Fe3 O4 + 4H2

the 4 in H2

All of the following are signs that a chemical reaction may have taken place in a piece of glass EXCEPT __________.

the shape of the glass changes

All of the following describe uses of nonrenewable energy sources EXCEPT:

turning turbines with water held behind dams

In which of these examples does chemical energy change to electrical energy?

using a battery.

Which of these processes are chemical reactions?

vegetables rotting

Match these descriptions of different kinds of chemical reactions with the type of reaction. A compound breaks down. This reaction has one reactant and two or more products. Energy, as from a battery, is usually needed to break the compound apart. Two substances combine to form one substance. An example of this kind of reaction is rusting, in which iron reacts with oxygen. This reaction requires energy to start, but it releases more energy than is required to start it. Oxygen is always a reactant, and the products are usually carbon dioxide and water. An atom from one reactant replaces an atom in the other reactant. This kind of reaction has two reactants and two products. An example is the neutralization of an acid and an alkali.

decomposition synthesis combusition replacement

True or False. Activating a cold pack involves a reaction that releases heat.

false, absorbs

Which of the following is a combustion reaction?

methane + oxygen -> carbon dioxide + water

This equation is an example of what type of reaction? Select all that apply. NaOH + HCl → H2O + NaCl

neutralization, double replacement

A catalyst is used in the chemical reaction to break down hydrogen peroxide (H2O2) into water and oxygen. At the end of the reaction, the catalyst is __________.

unchanged because it only speeds up the reaction