Basic Chemical Reactions

The Law of Conservation of Mass states

• that matter exists in all states and reacts the same

• that matter can only be changed into new substances by introducing a catalyst

• that matter exists in the same state throughout any chemical change

• that matter cannot be created or destroyed and that the mass of the products must equal the mass of the reactants

Tags

NGSS.MS-PS1-5

Is this chemical equation balanced? Why or why not? Choose the BEST answer.

• Yes, the amount of atoms for each element are equal on both the reactant and product side.

• No, the carbons are not the same number on both the reactant and product side.

• No, neither the carbons or hydrogens are the same amount on both the reactant and product side.

• No, none of the elements (carbon, hydrogen, or oxygen) are the same amount on both the reactant and product side.

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

In a chemical reaction

• The atoms of the reactants always stay together to form the products

• The atoms of the reactants unbond, rearrange, and then rebond to form the products

• New atoms are formed which combine to make the products

• Some atoms disappear while others multiply to form the products

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

What type of reaction is illustrated below?

• synthesis

• decomposition

• single replacement

• double replacement

In the equation,          2Mg + O₂ ---> 2MgO, which are the reactants?

• Mg and O

• MgO

• Mg and MgO

• O and MgO

An element plus additional element reacts to form one product is an example of which type of chemical reaction? 

• combustion

• decomposition 

• synthesis 

• single replacement

Describes the number of molecules in a compound and is used to balance a chemical reaction. 

• coefficient 

• subscript

• superscript

• SI unit

What type of chemical reaction takes place when fluorine reacts with sodium bromide?

• single replacement 

• double replacement 

• combustion

• synthesis 

Tags

NGSS.MS-PS1-5

A compound is reacted and forms two new substances. What type of reaction is this?

• combustion 

• synthesis 

• decomposition 

• single replacement 

Tags

NGSS.MS-PS1-2

What are the correct coefficients when this equation is balanced?
KClO₃  --> KCl  +  O₂

• 2,2,2

• 2,2,3

• 1,2,3

• 3,3,3

Tags

NGSS.MS-PS1-5