HONORS Unit 6 Chemical Equations PRE/POST Test

4Si + S₈ --> 2Si₂S₄

• Synthesis
• Decomposition
• Single displacement
• Double displacement

Tags

NGSS.MS-PS1-2

What is a precipitate?

• A solid formed from a single replacement reaction
• An aqueous compound formed from single replacement reaction 
• An aqueous compound formed from double replacement reaction
• A solid formed from a double replacement reaction

How many HCl molecules do you need to balance this equation? 
Mg +  __HCl --->  MgCl₂ + H₂

• 1
• 2
• 3
• 4

Tags

NGSS.MS-PS1-5

Which of the following shows the correct way to balance the chemical equation?
Fe + O₂ -> Fe₂O₃

• 4Fe + 3O₂ -> 2Fe₂O₃
• 2 Fe + 3O₂ -> Fe₂O₆
• 4 Fe + O₆ -> 2Fe₂O₃
• None of the options are correctly balanced.

Tags

NGSS.MS-PS1-5

The red numbers in the image below represent ________

• subscripts
• coefficients
• I don't know, and don't want to try
• None of the answers are correct

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

• Mg and O
• MgO
• Mg and MgO
• O and MgO

How many atoms are there TOTAL in:
H₂SO₄

• 6
• 5
• 7
• 3

Why is the following chemical equation not balanced?
H_{2 +} O₂ --> H₂O

• each side of the equation has a different number of oxygen atoms
• each side of the equation has a different number of hydrogen atoms
• each side has the same mass
• the arrow is pointing in the wrong direction

At the end of chemical reactions, what is the total mass of the reactants compared to the total mass of the products?

• the product is doubled
• the product is half the mass of the reactants
• the mass is the same
• the mass changes depending on the reaction

How would this equation be classified?

2H₂O --> O₂ + 2H₂

• Synthesis

• Decomposition

• Combustion

• Single Displacement