Chemical Reaction

Chemical Reactions

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Multiple Choice

How do we know a chemical reaction has taken place?

• Substances change in appearance

• Substances change in size

• Substances change in states, like from a liquid into a solid.

• New substances are formed

Multiple Choice

Which of the following is a reactant in the following equation?

O₂ + C₆H₁₂O₆ > CO₂ + H₂O

• CO₂

• H₂O

• O₂

Multiple Choice

Which of the following is a product in the following equation?

O₂ + C₆H₁₂O₆ > CO₂ + H₂O

• CO₂

• C₆H₁₂O₆

• O₂

Multiple Choice

Lighting a match is an example of

• an endothermic reaction

• an endergonic reaction

• both an endothermic and an endergonic reaction

• both an exothermic and an exergonic reaction

Multiple Choice

In the following equation, which is the catalyst?

H₂O₂ + Catalase > H₂O + O₂ + Catalase

• H₂O₂

• H₂O

• O₂

• Catalase

Multiple Choice

In which of the following has a chemical reaction taken place?

• An apple turning brown

• Milk developing a sour taste

• Smoke being released as a candle burns

• All of the previous

Multiple Choice

Tiny pieces of matter that everything is made of

• model

• atoms

• substances

Multiple Choice

An object, diagram, or computer program that helps us understand something by making it simpler or easier to see

• molecule

• property

• model

Multiple Choice

Something that can be observed about a substance, such as color, smell, or boiling point

• property

• reactant

• molecule

Multiple Choice

A process in which atoms rearrange to form new substances.

• extended structure

• boiling point

• chemical reaction

Multiple Choice

Something that is made of all the same atoms or groups of atoms

• substance

• atoms

• scale

Multiple Choice

A group of atoms joined together in a particular way

• product

• molecule

• fertilizer

Multiple Choice

In a chemical equation the reactants are on the left side of the arrow. Are the reactants the beginning substances or the ending substances?

• beginning

• ending

Multiple Choice

In a chemical equation the products are on the right side of the arrow. Are the products the beginning substances or the ending substances?

• beginning

• ending

Multiple Choice

During a chemical reaction, atoms can

• be destroyed to form a new substance

• be created to form a new substance

• be rearranged to form a new substance

Multiple Choice

Burning paper is an example of a

• boiling point

• chemical reaction

• extended structure

Multiple Choice

In a chemical equation, is it true that -

• the reactant side and product side can have different numbers of atoms for each element
• there can be different elements on the reactant side and the product side
• an element or compound must be accompanied by a phase change
• the coefficients indicate the number of molecules of each reactant used and the number of molecules of each product made

Multiple Choice

Which of the following models best demonstrates a balanced chemical equation?

• F
• G
• H
• J

Multiple Choice

The reactants are on the left side of the chemical equation.

• True
• False

Multiple Choice

How many atoms in all are in a molecule of serotonin?

C₁₀H₁₂N₂O

• 22
• 24
• 25
• 4

Multiple Choice

Coal contains carbon and other elements. Carbon dioxide forms when coal burns in the presence of oxygen. Which of these is the best evidence that a chemical reaction occurs when coal burns?

• The shape of the coal changes
• Oxygen is present
• A new substance is produced
• Coal is made up of more than one element

Multiple Choice

Is burning wood a chemical or physical change?

• chemical
• physical

Multiple Choice

Is glass breaking a chemical or phyiscal change?

• chemical
• physical

Multiple Choice

Is hammering wood together to build a house a chemical or physical change?

• chemical
• physical

Multiple Choice

Is a a rusting bicycle a chemical or physical change?

• chemcial
• physical

Multiple Choice

Is melting butter for popcorn a chemical or physical change?

• chemical
• physical

Multiple Choice

Is melting ice a chemical or physical change?

• chemical
• physical

Multiple Choice

Is spoiling food a physical or chemical change?

• phyiscal
• chemical

Multiple Choice

Is mixing lemonade powder with water a physical or chemical change?

• physical
• chemical

Multiple Choice

Is mowing the lawn a phyiscal or chemical change?

• physical
• chemical

Multiple Choice

Which of the following equations demonstrates an actual chemical reaction that forms a new substance? (HINT: it must follow the Law of Conservation of Mass)

• A
• B
• C
• D

Multiple Choice

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

• Reactants
• Products 
• Yields 
• Chemical Equation 

Multiple Choice

Is this balanced?
2HgO → 2Hg + O₂

• Yes
• No

Multiple Choice

Is this balanced?
Al + O₂ → 2Al₂O₃

• Yes
• No

Multiple Choice

When materials combine to form new compounds it is a chemical change. Which example is a chemical change?

• baking powder fizzing
• water boiling
• ice melting
• sugar cube dissolving

Multiple Choice

Which is an example of a chemical reaction?

• paper cut into small pieces
• chocolate melting in a pan
• flour and sugar mixed in a bowl
• cookies baking in an oven