freshofwater

What will happen as more and more people in China and India decide to buy automobiles?

How does the global effect of organizations on society?

(y - 3) (y - 6) = 0

y equals what ?

A 16.0ml aliquot of a 0.220M solution of H2S04 is titrated with a 0.211 M NaOH solution. What volume (mL)of base will it take to reach the equivalence point?

1. Which of the following samples contains the greatest number of molecules?
2. 1 g phosphorus, P4                                                 1 g nitrogen, N2
3. 1 g chlorine, Cl2                                                                  1 g sulfur, S8

7 How may Na ions (Na+) are present in 0.500 mol NaOH?

1. 20 x 1023                                                                     C. 3.01 x 1023
2. 51 x 1023                                                            D. 6.02 x 1023

1. Acetic acid, the acid present in vinegar, has the empirical formula of CH2 If the Molar mass of the acid is 60 g/mol, what is its molecular formula?
   1. 2CH2O                C2H2O2                                C. CH4O                      D. C2H4O2

1. The limiting reagent in a chemical reaction is one that:

     A.is consumed completely.                                                 

1. has the smallest coefficient.
2. has the smallest molar mass (formula weight).
3. has the largest molar mass (formula weight).

10.Which of the following statements is TRUE for the chemical equation given        below in which nitrogen gas reacts with hydrogen gas to form ammonia gas        assuming the reaction goes to completion?

                                       N2 + H2      →    NH3

1. The reaction of three moles of hydrogen gas will produce 34 g of ammonia.
2. One mole of N2 will produce one moles of NH3.
3. One mole of nitrogen produces  02 x 1023 molecules of ammonia.
4. The reaction of one mole of H2 will produce 1/2 moles of NH3.

1. Which of the following contains the smallest percentage of iron?

A. pyrite (FeS2)                                                        C.  magnetite (Fe3O4)

B. hematite (Fe2O3)                                                D. siderite (FeCO3)

1. How many moles of Ca atoms are there in 0.40 g of the element?

A.60                          B. 0.10                       C. 010                         D. 16               

1. What is the percent nitrogen in the compound ammonium nitrate?

A.5 g                  B.  50.5 g                    C.  70.0 g                     D.  35.0 g

4. Consider the equation: NaOH +   Cl2 +   NH3   →   N2H4  +   H2O + NaCl      If 45.0 g of NaOH is allowed to react with 100 g of Cl2,which will be the limiting       reagent?

A.NaOH                          

B.  Cl2                   

C.  N2H4                                    

D. NaCl

5. How many moles of O atoms are there in 1 mole of magnesium sulfate heptahydrate?

A.7                                     

 B. 11                         

C. 4                            

D. 10

Solve the following problems. show your complete solution

1.Ethanol, the alcohol contained in alcoholic beverages, is composed of 52.2% C, 0% H, and oxygen. Its molar mass is 46.0 g/mol. (a) what is the empirical  formula of  ethanol? (b) What is its molecular formula? (5 points)