Structure of Chemical Reactions

Properties and Chemical Reactions Tutorial

by David Blankenship

Multiple Select

Which chemical reaction involving water is a decomposition reaction (breaking up) and which is a synthesis (building up) reaction? If you’re not sure, take a guess.

• Water breaking down into hydrogen and oxygen is a synthesis reaction.

• Water breaking down into hydrogen and oxygen is a decomposition reaction.

• Hydrogen and oxygen combining to form water is a synthesis reaction.

• Hydrogen and oxygen combining to form water is a decomposition reaction.

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Multiple Choice

What is the left part of a chemical equation called? H_{2 +} O → H₂O

• Reactants

• Products 

• Yields 

• Chemical Equation 

Multiple Choice

What is the right part of a chemical equation called? H_{2 +} O → H₂O

• Reactants

• Products 

• Yields 

• Chemical Equation 

Multiple Choice

2H₂ + O₂ ----> 2H₂O What is the product?

• ------>

• 2H₂O

• 2H₂+ O₂

Multiple Choice

CaCO₃ represents a chemical

• Symbol

• Formula

• Subscript

• Reaction

Multiple Choice

How many products are in A + B ---> C ?

• 1

• 2

• 3

• 4

Multiple Choice

How many reactants are in A + B ---> C ?

• 1

• 2

• 3

• 4

Multiple Select

Which of these events indicate that a chemical reaction might have occurred?

• Silver jewelry becomes dark because of tarnish.

• Water evaporates from salt water and leaves salt behind.

• A liquid bubbles when heated.

• A solid appears when two water-based solutions are added together.

Multiple Choice

A scientist compares two samples of colorless gas present at the beginning and end of a lab process. She wants to determine whether a chemical reaction has occurred. She tests whether each gas is flammable. Neither gas burns when lit. She then measures the amount of each gas. Sample one has a volume of 53 cm³ and a mass of 0.10 g. Sample two has a volume of 39 cm³ and a mass of 0.05 g. What are the scientist’s findings?

• The flammability test shows that the gases are the same, so a chemical reaction did not occur.

• The flammability test shows that the gases are different, so a chemical reaction occurred.

• Density calculations show that the gases are the same, so a chemical reaction did not occur.

• Density calculations show that the gases are different, so a chemical reaction occurred.

Multiple Select

Which observations show that a change in state of matter has occurred?

• Wood burns, producing gas and an ashy residue.

• Overnight, dew forms on the grass.

• An alkali indicator changes color when added to a cleaner.

• Vinegar has a strong smell.

Multiple Choice

Physical or chemical change? cutting a piece of paper in half

• Physical

• Chemical

Multiple Choice

Physical or chemical change? sugar is dissolved into hot tea

• Physical

• Chemical

Multiple Choice

Physical or chemical property? density

• Physical

• Chemical

Multiple Choice

Over time, pure silver that is exposed to air turns a strange greyish brown color. This is an example of a ________________ change. 

• Physical

• Chemical

Multiple Choice

A change in which the form or shape of a substance changes but the chemical makeup of the substance remains the same.

• chemical change

• reaction

• physical change

• solution

Multiple Choice

Example for Physical Property

• Taste

• explodes

Multiple Choice

Example for Physical property

• Odor

• burns in air

Multiple Choice

Blue Color

• Physical Property

• Chemical Property

Multiple Choice

Density

• Physical Property

• Chemical Property

Multiple Choice

Flammability (burns)

• Physical Property

• Chemical Property

Multiple Choice

Solubility (dissolves)

• Physical Proeprty

• Chemical Property

Multiple Choice

Reacts with acid

• Physical Property

• Chemical Property

Multiple Choice

Melting point

• Physical Property

• Chemical Property

Multiple Choice

Hardness

• Physical Property

• Chemical Property

Multiple Choice

Reacts with water

• Physical Property

• Chemical Property

Multiple Choice

A student removes a loaf of bread hot from the oven. The student cuts a slice off the loaf and spreads butter on it. 

• Physical Change

• Chemical Change

Multiple Select

Which actions show that mixing or separating occurred?

• purifying water with a carbon filter

• a soda fizzing when its cap is opened

• a metal mixed with a very small amount of a nonmetal to make a metallic alloy

• using frozen carbon dioxide to create fog

Multiple Choice

Combining substances to form a new substance

• Displacement

• Synthesis

• Decomposition

• Oxidation

Multiple Choice

Breaking down a substance into simpler substances

• Displacement

• Synthesis

• Decomposition

• Oxidation

Multiple Choice

Switching one substance for another

• Replacement

• Synthesis

• Decomposition

• Oxidation

Multiple Choice

What type of reaction involves the breaking down of a substance into simpler substances?

• Single Replacement Reaction

• Double Replacement Reaction

• Synthesis Reaction

• Decomposition Reaction

Multiple Choice

What type of reaction involves 2 substances combining to form 1 new compound?

• Decomposition Reaction

• Single Replacement Reaction

• Double Replacement Reaction

• Synthesis Reaction

Multiple Choice

What type of reaction involves one element replacing another element in a compound?

• Single Replacement Reaction

• Double Replacement Reaction

• Synthesis Reaction

• Decomposition Reaction

Multiple Choice

What type of reaction involves ions from 2 compounds exchanging places to form 2 completely new compounds?

• Single Replacement Reaction

• Double Replacement Reaction

• Synthesis Reaction

• Decomposition Reaction

Multiple Choice

What type of chemical reaction is this one?

Al(OH)₃ --> Al2O3 + H2O

• Decomposition

• Combustion

• Synthesis

• Single Replacement

Multiple Choice

What type of chemical reaction is this one?

CUO + CO2 --> CuCO3

• Decomposition

• Combustion

• Synthesis

• Single Replacement

Multiple Choice

What type of chemical reaction is this one?

Ca + MgCl2 --> CaCl2 + Mg

• Decomposition

• Combustion

• Synthesis

• Single Replacement

Multiple Choice

A chain of repeating units (called monomers)

• monomer

• dimer

• replicate

• polymer

Multiple Choice

Why do you think people use plastic for their products ?

• Because it's strong

• Because its very cheap and it's easy to make

• Because it's expensive

• Because it's rare and it's good for the enviorment

Multiple Choice

Define polymer

• circular molecule made with many repeating units

• short molecule made of a few repeating units

• long, chain-like molecule made of repeating units

• chain-like molecule that contains hydrogen and oxygen