Review Quiz on Mole Concept, Chemical Bonding, Volcanoes, Conste

What did ancient Chinese astronomers believe about the constellations? They ______________________.
   

• were merely decorative patterns in the sky
     

• had no effect on human life
     

• were connected to the fate of the emperor and the state
    

• changed positions every year

In ancient Japan, what was the main purpose of studying constellations? To ________________________________.

• create art and literature                          

• develop new technologies
                             

• predict agricultural seasons and events 

• measure time accurately

Determine the chemical formula of citric acid, if 12 grams of carbon react with 16 grams of hydrogen and 14 grams of oxygen.

• C₃H₄O₇          

• C₂H₁₈O₇               

• C₆H₈O₇                             

•   C₁₂H₈O₁₄     

Answer explanation

The presence of SO₂ in the atmosphere contributes to acid rain. What percentage of sulfur is present in SO₂ (formula mass = 64.07 g/mol)? _____ %

                           

•   40                           

• 96                

•    60                                  

•    50.05

Answer explanation

SCC community commonly use hydrogen peroxide (H₂O₂, molar mass = 34.02 g/mol) to clean their wounds. If CJ used 1 gram of H₂O₂ , how many moles of H₂O₂ did he use? _____ mole

                          

•   0.035                     

•   0.030                   

• 0.029                               

•  0.025

Answer explanation

How many nitrogen gas molecules (N₂) are found in an 8.5-mole sample?

                            

• 5.12 x 10²⁴              

•  5.12 x 10²³          

• 4.14 x 10²⁴                       

• 4.14 x 10²⁴

Answer explanation

What percentage of carbon is present in carbon dioxide (CO₂)? ___ %

                           

•   10                           

•  27             

•            50                                     

• 73

Answer explanation

How many carbon dioxide molecules are present  in a 120-gram sample of CO₂?

                            

•  1.20 x 10²⁴               

• 1.20 x 10²³           

• 1.64 x 10²⁴                   

•    1.64 x 10²³

Answer explanation

What is the relationship between moles and molar mass?
                         

• Moles =Mass/Molar mass                     

• Mass = Moles + Molar mass
                             

• Molar mass = Moles x Mass                     

• Moles = Mass x Molar mass

You have 1 mole of hydrogen gas (H₂) and 1 mole of oxygen gas (O₂). Which sample has more molecules?
    

• Hydrogen gas                                

•   Oxygen gas       
     

• The same number of molecules                

• Cannot be determined

Answer explanation