Chemical Reaction STUDY GUIDE

The substances on the left side of the arrow are...

• products

• reactants

• inhibitors

• catalysts

Answer explanation

The substances on the left side of the arrow are reactants.

The red numbers in the image below represent ________

• subscripts

• coefficients

• chemical formulas

• compounds

Answer explanation

The red numbers in the image below represent coefficients.

2 NaBr + 1 Ca(OH)₂ ----> 1 CaBr₂ + 2 NaOH

• Synthesis (or combination)

• Decomposition

• Single displacement

• Double displacement

Answer explanation

The given chemical equation involves the exchange of ions between the reactants, resulting in the formation of new compounds. This type of reaction is known as double displacement.

2 NH₃+ 1 H₂SO₄ ----> 1 (NH₄)₂SO₄

• Synthesis (or combination)

• Decomposition

• Single displacement

• Double displacement

Answer explanation

The correct choice is Synthesis (or combination) because the reaction involves the combination of NH3 and H2SO4 to form (NH4)2SO4.

2 NO₂ ----> 2 O₂ + N₂

• Synthesis (or combination)

• Decomposition

• Single displacement

• Double displacement

Answer explanation

The given chemical equation shows the breakdown of 2 NO2 molecules into 2 O2 molecules and 1 N2 molecule, indicating a decomposition reaction.

What does the Law of Conservation of Mass state?

• Matter cannot be gained or lost in a chemical reaction.

• Matter can only be lost in a chemical reaction.

• Matter can only be gained in a chemical reaction.

• Matter can be gained and lost in a chemical reaction. 

Answer explanation

The Law of Conservation of Mass states that matter cannot be gained or lost in a chemical reaction.

What is the left part of a chemical equation called?
2H_{2 +} O₂ --> 2H₂O

• Reactants

• Products 

• Yields 

• Chemical Equation 

Answer explanation

The left part of a chemical equation is called Reactants, which are the substances present before the reaction occurs.

What is the total number of atoms present in 5Na₃PO₄

• 5

• 40

• 55

• 8

Answer explanation

The total number of atoms in 5Na3PO4 is calculated by adding the individual atoms present: 5*3(Na) + 1*1(P) + 4*4(O) = 40 atoms.

How many Mn atoms are found in the following compound?
3Cr(MnO₄)₆

• 3

• 4

• 6

• 18

Answer explanation

The compound contains 6 Mn atoms in each MnO4 group, and there are 3 groups, so the total number of Mn atoms is 6 x 3 = 18.

What is the little number after an element in a chemical equation called.
Example: H₂

• Coefficient 

• Subscript

• Atom

• Equation

Answer explanation

The little number after an element in a chemical equation is called a Subscript.