Mid-Unit 3 Test Review- Chemical Reactions

According to the law of conservation of mass, which statement is true?

• Mass can be created by chemical reactions.

• The mass of the products in a chemical reaction do not have to equal the mass of the reactants.

• Mass can neither be created nor destroyed.

• Mass can only be destroyed by physical transformations.

Tags

NGSS.MS-PS1-5

Which of the following chemical equations proves that the law of conservation of mass is in effect?

• Mg₂ + LiBr ---> LiMg + Br

• 2KCl + F₂ ---> 2KF + Cl₂

• Na +O₂ ---> Na₂O

• H₂0 ---> H₂ + O₂

Tags

NGSS.MS-PS1-5

For the following synthesis reaction what coefficient would need to be added in front of the water molecule to make it balanced?

NH₄NO₃ -----> N₂O + H₂O

• None. It is already balanced.

• 1

• 2

• 3

Tags

NGSS.MS-PS1-5

Decomposition reactions are similar to synthesis (combination) reactant because they are opposite of one another.

• True

• False

According to the following equation, which of the following element(s)/molecule(s) is/are not balanced?

Cu + AgNO₃ ----> Cu(NO₃)₂ + Ag

• Cu, NO₃

• NO₃

• It is balanced

• Cu, NO_3,  and Ag

Tags

NGSS.MS-PS1-5

Using the reactivity series as your guide would the following reaction for water and copper take place?

H₂O + Cu --->

• Yes a reaction occurs.

• There will NOT be a reaction.

Tags

NGSS.MS-PS1-2

Balance the following equation, then select which statement is correct.

AgNO₃ + K₂SO₄ ---> Ag₂SO₄ + KNO₃

 

• The equation is balanced.

• To balance you must add a subscript of 2 to both the Ag and the K.

• To balance the equation, you must add a coefficient of 2 to the AgNO3 molecule AND a 2 to the KNO₃ on the products side.

• To balance the equation, you must add a coefficient of 2 to the KNO₃ molecule.

Tags

NGSS.MS-PS1-5

Looking at the equation below AND your guide for if halogens will react , would the following single-displacement reaction occur?

Cl₂ + MgI₂ ---> I₂ + MgCl₂

• TRUE! Yes it will occur.

• FALSE. This reaction will NOT occur.

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5