Question

1. How many grams of NaCl are required to prepare 500. ml of 1.20M NaCl solution?

2. ) Write the balanced equation for the reaction that occurs when sulfuric acid, H2SO4 is titrated with the base, sodium hydroxide, NaOH. Sodium sulfate, Na2SO4 is the salt produced.

3. SO2 gas is in a 2.0L flask at STP (0 o C, 1 atm).

A. Using the Ideal Gas Law, determine the concentration of the gas in moles/L

B. Calculate the density of the gas in g/L.

4. You burn 150.0g C4H10O in 320.0g O2. The unbalanced equation for the reaction is :

C4H10 + O2 --> CO2 + H2O

A. Balance the equation

B. How many moles of each reactant are you starting with?

C. How many moles of CO2 may actually be produced? Note: determine the limiting reactant?

D.  After the reaction is run, it is determined that 220.0g CO2 are actually produced. What is your percent yield?

5.  A 1.00M solution of Ba(OH)2 is used to titrate a solution of H3PO4 of unknown concentration. At the end of the titration it’s found that 42.00 ml of Ba(OH)2 and 40.00 ml of H3PO4 were used to reach the endpoint.

The balanced equation for the reaction is: 3Ba(OH)2 + 2H3PO4 --> 6H2O + Ba(PO4)2

A.  How many moles of Ba(OH)2 were used?

B. How many moles of H3PO4 are required to react with that much Ba(OH)2?

C. What is the concentration of the H3PO4 in moles/L?

6. GIven the unbalanced equation : PbO2 --> PbO + O2

A. Balance the equation

B.  How many liters of O2 gas at 27o C and 1.00 atm can be made from the decomposition of 478.4g PbO2? The molar mass of PbO2 is 239.2g/mole, for O2 it’s 32.00g/mole and for PbO it’s 223.2g/mole. Hint: do the stoichiometry first. Determine how much O2 gas may be produced from 478.4g PbO2. Then determine the volume of the gas.

Answer 1