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Given the equation 10 Na + 2 NaNo3. ------ 6 Na2O + N2

How many grams of NaNo3 must be reacted in order to produce 4.5 g of Na2O?

Given the equation 6 K + B2O3----- 3 K2O + 2B

How many grams of B will be produced if you react 6.25 g of K are reacted?

Given the equation 10 Na + 2 NaNO3--- 6 Na20 + N2

How many grams of Na must be reacted in order to produce 30g of Na2O?

Given the equation 6K + B2O3 ---- 3 K2O + 2B

If i react 2.5 g of B2O3 How many grams of B will be produced?

Given 2 H3PO4 + 3 Mg(Oh)2---Mg3(PO4)2 + 6 H2O

If you react 2.75 g of Mg(OH)2 you will produce how many grams of H2O?

Given 2 H3PO4 + 3 Mg(OH)2 --- Mg3(PO4)2 + 6 H20

How many grams of H3PO4 must be reacted in order to produce 0.33 g of H2O?

Given 2 H3PO4 + 3 Mg (OH)2---Mg(PO4)2 + 6 H2O

How many grams of H3PO4 must be reacted with 10.55 g of Mg (OH)2?

Given 2 H3PO4 + 3 Mg (OH)2 --- Mg3 (PO4)2 + 6 H2O

How many grams of H2O will be produced in the same reaction that produces 2.68 g of Mg3 (PO4)2?

The normal boiling point of C6H5Br is 156.15 celsius . Using Trouton’s Rule find the

vapor pressure at 100 Celsius and compare with the observed value of 141.1 mm Hg.

  1. Determine the pH of the solution after the addition of 6.64 mL of 2.30 M hydrobromic acid (HBr) to 507 mL of 0.631 M sodium hydrogen phosphate (Na2HPO4).

10. Consider 25.0mL of 0.100M HA (HA is a fictional acid), for which Ka=1.00x10-5, titrated with 0.0500M NaOH solution. What is the initial pH before adding any titrate? (4 marks)

11. 50.0mL of 0.185M Sr(OH)2 is reacted with 35.0mL of a solution containing 0.130g of HCl. a. Calculate the pOH resulting from the mixture. (8 marks) b. Suggest an indicator that will be effective for this incomplete titration and explain your choice. (2 marks)

6. Determine if the pH at the equivalence point is 7, >7 or <7 for the following titrations: (3 marks)

a. NH3 titrated with HCl

b. Ba(OH)2 titrated with HCl

c. HF titrated with NaOH

7. In a titration, 34.8 mL of 0.115M HNO3 were required to neutralize 25mL of solution of Ca(OH)2. What was the original concentration of the Ca(OH)2 solution? Include the neutralization equation for full marks. (4 marks)

The decomposition of N2O5 is an important process in tropospheric chemistry. The half-life

for the first order decomposition of this compound is 2.05X104 s. How long will it take for a

sample of N2O5 to decay to 60% of its initial value?

A balloon contains a mixture of 3 gases: oxygen, helium, and nitrogen. If the partial pressures of the three gases in the balloon are 25 atm of O2, 7,600 torr of N2, and 20 atm of He, What is the total pressure inside the balloon?

An electrochemical cell consists of a nickel electrode in an acidic solution of 1.00M Ni(No3)2 connected by a salt bridge for a second component with na Al electrode in acidic solution of 1M Alcl3. Calculate the change in voltage when the cell described above has initial conc of 0.500M Ni(No3)2 and 0.750 M Alcl3?

During an experiment, 78.0 grams of CH4 reacts with 102.0 grams of O2 to produce water and carbon dioxide (CO2).

CH4 + 2O2 ---> 2H2O + CO2

Mole Ratio: Molar Mass Ratio:

1 mol CH4 = 1 mol CO2 1 mol CH4 = 16.01 g CH4

1 mol CO2 = 44.01 g CO2

Whenever solid calcium hydroxide, Ca(OH)2 (commonly known as lime) is present in water, it dissolves according to the equation:

Ca(OH)2(s)   ↔  Ca2+(aq)  +  2OH-(aq)

until the rate of the backward reaction equals the rate of the forward reaction and the solution is saturated.

A CAPE Chemistry student sought to determine the solubility product, Ksp of calcium hydroxide by titrating saturated solution of Ca(OH)2 against standardized hydrochloric acid solution, HCl. The saturated Ca(OH)2 solution was filtered, to remove excess solute, and 25mL aliquots were titrated against 0.10M HCl solution using bromothymol blue indicator.

  1. Calculate the concentration of Calcium Hydroxide. 
  2. Use the equilibrium expression for the dissolution of Ca(OH)2 to determine the concentration of Ca2+ and OH
  3. Calculate the Ksp for calcium hydroxide (state the units). 
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