General Chemistry Answers

For #1-3, consider the reaction:

3 NaOH(aq) + 3 FeCl3 → NaCl (aq) + 3 Fe(OH)3 (s)

1) What mass of Fe(OH)3 would be produced if 250 mL of 0.250 M NaOH were added to a solution containing excess FeCl3?

2) What volume of 2M NaOH will react with 34.0 g of FeCl3?

3) What is the concentration of 20.50 mL of NaOH if this was neutralized with 20.0 mL of 0.150 M HCl in the reaction

NaOH + HCl → NaCl + HOH

a) Describe in detail the concept of conjugate acid-base pairs using the equation below to illustrate your answer. [4 marks] H3PO4 + NaOH→ NaH2PO4 + H2O (b) To ascertain the purity of an active ingredient X, an aqueous solution of X needs to be titrated against 0.50 M HCl. What should be the pH of an aqueous solution of 0.50 M HCl? [3 marks]

calculate the theoretical yield of alf3 obtained from 0.45 moles of al in the reaction

Consider the reaction that has reached a state of equilibrium at 200^oC:

2HCl(g) + O2(g) ⇌ 2Cl2(g) + 2H2O(g)   exothermic

Determine whether each of the following will increase the equilibrium concentration of Cl2 product. Explain your reasoning.

a. Remove H2O gas

b. Remove HCl gas

c. Removing Cl2 gas.

d. Increasing the temperature of the system: 

e. Decreasing the pressure in the reaction vessel: 

Consider the reaction that has reached a state of equilibrium at 200^oC:

2HCl_(g) + O_2(g) ⇌ 2Cl_2(g) + 2H₂O_(g)      exothermic

Determine whether each of the following will increase the equilibrium concentration of Cl₂ product. Explain your reasoning.

a.   Remove H₂O gas

b.   Remove HCl gas

c.    Removing Cl₂ gas.

d.   Increasing the temperature of the system:

e.   Decreasing the pressure in the reaction vessel:

The osmotic pressure of an aqueous solution of a nonvolatile nonelectrolyte solute is 2.17 atm at 0.0°C.

a. What equation will you use?

b. Identify the hypothetical value of the van’t Hoff factor.

c. Calculate for the molarity (M) of the solution.

how many moles of water is 5.87 x 10^22 molecules ?

1) A solution is prepared by dissolving 5.02 g of KNO3 in 95.0 g of water. Calculate the following:

a) Mole fraction of the solute and the solvent

b) % mass of the solute

c) Concentration of solution in ppm

2) What is the mass in grams of KCl present in 23.0 g KCl of 12.50 KCl solution?

4. A gas expands and does P-V work on the surroundings, equal to 279 J. At the same time it absorbs 216 J of heat from he surroundings. What is the change in energy of the gas?

3. A gas expands in volume from 26.7 mL to 89.3 mL at constant temperature. Calculate the work done (in joules) if the gas expands.

  a.) against a vacuum

  b.) against a constant pressure if 1.5 atm and,

  c.) against a constant pressure of 2.8 atm