Unit 4 Take Home Test                                                                                                                        Name______________________

Science 1                                                                                                                                               Date____________ Period______

 

___1. Why must chemical equations be balanced?

 

___2.  Define "reactants" ___________________________________________________________________________________

___3.  Define "products"____________________________________________________________________________________

___4. Pg. 471 #1  (Explain how you know)

 

 

___5.  Pg. 471 #2

 

 

 

6.  Pg. 471 # 3

                ___a)

 

                ___b)

 

                ___c)

 

7. How many of each atom is in the following chemical formulas:

 

                ___a) 3MgO

 

                ___b) 2C6H12O6

 

                ___c) 5Mg(OH)2

 

                ___d) 2Al2(PO4)3

 

                ___e)  3H2SO4

 

 

 

___8. In a chemical equation what does a coefficient do?___________________________________________________________

 

 

___9. In a chemical equation what does a subscript do?____________________________________________________________

 

 

___10.  What does a subscript do if it follows atoms in parentheses?__________________________________________________

 

11.           ___a) What is a hydronium ion?________________________________________________________________________

___b) What is its charge and why does it have that charge?__________________________________________________

___c) What is a hydroxyl ion?_________________________________________________________________________

___d) What is its charge and why does it have that charge?__________________________________________________

 

___12. If a solution is an acid it has more _______________ ions than ________________ ions?

 

___13. Pure water has a pH of 7.  Explain why?  Why do we call it neutral?

 

14.  What is the pH for the following ratios of hydronium ions to water molecules? Acid or Base?

___a) 1 :  100,000                                                                                                  

___b) 1 :  100,000,000,000       

___c) 1 :  100  

 

15.  Write the ratio of hydronium ions to water molecules for the following pH's. Acid or Base?

      ___a)  pH = 3

      ___b) pH = 12

      ___c) pH = 6

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