3Q PRACTICE EXAM.  Answers here 

1.  Chocolate milk can be classified as a mixture, compound, element, formula unit, polar bond

2.  (5.81)(0.015) will have a product with how many significant figures?   1   2   3   4

3.  Uranium has ___ protons, ____ neutrons, and _____ electrons

4.  Match up the atomic models with the Chemists: 
     plum pudding ______, 
     billiard balls ___________, 
     electrons flying around the nucleus (somewhere)  _______
     electrons in fixed orbits (like the planets flying around the sun) __________, 

5.  A compound is named Iron (IV) oxide. The roman numeral indicates _________________

6.  You find 2 identical jars of gas at STP. One is labeled carbon dioxide the other is labeled nitrogen.  
     The first label also says that there are 6.02 x 10²³ molecules of gas. 
     How many molecules are in the other one?  How do you know?

7. Write a balanced equation for: Magnesium plus nitrogen yields magnesium nitride

8.  If a particular gas is at 2 atm and 546 K and it is changed to STP, what happened:
a. the pressure halved and the temperature halved
b. the pressure doubled and the temperature doubled
c. the pressure doubled and the temperature halved
d. the pressure halved and the temperature doubled

9.  In the diagram at right, which is a heating 
     curve, put a circle around the segments 
     where kinetic energy is increasing and a 
     square around segments that potential 
     energy is increasing.

     AB     BC     CD     DE     EF

10.  Calcium gets excited. Write a possible 
      electron configuration for the excited atom.

11.  Which of these compounds is ionic (circle all that are)  
     NaCl      CCl₄      CH₄      CaO       MgO      CO₄      SiO₂      HCl      Na₂O      NH₃

12.  Define alloy, coordinate covalent bond, and isotope.

13.  skip this one, you know the drill around here.

14.  For these three compounds CO₂ , H₂O, and H₂ ,determine if they are asymmetrical and polar;   
      asymmetrical and non polar;   symmetrical and polar;  or, symmetrical and non polar 

15.  When 12 moles of glucose completely combusts, how many moles of carbon dioxide are produced?
      (glucose is written as: C₆H₁₂O₆₎  Write the balanced equation to START.  

16.  100 grams of copper (II) sulfate pentahydrate are in a test tube. 
       How many of those 100 grams are made up only of water?

17.  Aqueous aluminum chloride and aqueous sodium phosphate combine in a double replacement reaction. 
      Name the products and decide if they are aqueous or precipitate solids.

18.  Write the formulas and then draw Lewis dot diagrams for these compounds: 

19.  HCl + NaOH ---> NaCl + H₂O is a balanced equation. 75.0 grams of sodium hydroxide will produce
       how many grams of sodium chloride? (watch significant figures)

20.  50.0 grams of water at 20.0º C is converted to steam at 100.0º C.  How many joules of heat are 
       required to do this? (watch significant figures) MULTIPLE STEPS.  MULTIPLE FORMULAS TOO.

answers