Chemical Reactions

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

Tags

NGSS.MS-PS1-5

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

• F

• G

• H

• J

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

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

Tags

NGSS.MS-PS1-2

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

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

Identify the following chemical reaction.

• Synthesis (or combination)

• Decomposition

• Single displacement

• Double displacement

Identify the following chemical reaction.

3 HBr + 1 Al(OH)₃ ----> 3 H­₂O + 1 AlBr₃

• Synthesis (or combination)

• Decomposition

• Single displacement

• Double displacement

Identify the following chemical reaction.

Pb + FeSO₄ ----> PbSO₄ + Fe

• Synthesis (or combination)

• Decomposition

• Single displacement

• Double displacement

Tags

NGSS.MS-PS1-2

What reaction has the following general formula:

AB + CD --> CB + AD

• Synthesis

• Decomposition

• Single Replacement

• Double Replacement

• Combustion

What reaction has the following general formula:

A + B --> AB

• Synthesis

• Decomposition

• Single Replacement

• Double Replacement

• Combustion

Which chemical reaction always starts with a hydrocarbon that reacts with oxygen and produces carbon dioxide and water?

• Decomposition

• Synthesis

• Combustion

• Single Replacement