General Chemistry Answers

The freezing point of an aqueous solution that contains a non-electrolyte is 9.0°C.

a. What is the freezing-point depression of the solution?

b. What is the molal concentration of the solution?

A   lab  technician poured 0.200  kg  water  at  0.00 Celsius into  a  vessel  which  contains  liquid oxygen  at -183  Celsius.  Find  the number  of  gram  of  Oxygen  that  vaporizes. (boiling  point  of  oxygen = -183  Celsius)

What happens when phthalic anhydride (C8H4O3) is mixed with Terpin-Hydrate (C10H22O3)??

1. Camphor (C10H1602) freezes at 175 °C, and it has a particularly large freezingpoint-depression constant, K = 40.0 °C/m. When 0.086 g of an organic substance of unknown molar mass is dissolved in 22.01 g of liquid camphor, the freezing point of the mixture is found to be 1.7 °C below of pure camphor. What is the molar mass of the solute?

2. You add 0.25 g of an unknown solute to 11.1 g of benzene. The boiling point of the benzene rises from 80.10 °C to 80.46 °C. What is the molar mass of the compound? Ko=2.53 °C /m

3. A solution of an unknown non-dissociating solute was prepared by dissolving 0.300 g of the substance in 40.0 g of CC14. The boiling point of the solution was 0.357 °C higher than that of the pure solvent. Calculate the molar mass of the solute. Ko=5.02 C/m

Note: Provide complete solution.

If it takes 25 mL of 0.05 M HCl to neutralize 345 mL of NaOH solution, what is the concentration

of the NaOH solution?

i. Calculate the amount of nitric acid in terms molarity and in terms of number of moles 

ii. Differentiate molarity and number of moles.

3. A 0.010 mol sample of barium nitrate formed was heated until it had completely decomposed according to the following balanced equation:

2Ba (NO3)2(s) ˗˗˗˗˗˗˗˗˗˃˃ 2 BaO(s) + 4 NO2 (g) + O2(g)

a) Use the ideal gas equation to calculate the total volume, cm3, of gaseous products obtained at 387 K and 1.12 × 105Pa.

b) The Kinetic Theory of gases is an attempt to explain the properties (behaviour) of ideal gases. What assumptions (at least three) does this theory make about gas molecules?

A 2.36-gram sample of NaHCO, was completely decomposed in an experiment.

2NaHCO3-Na2CO, + H2CO3

In this experiment carbon dioxide and water vapors combine to form H2CO3. After decomposition the Na2C0s had a mass of 1.57 grams.

A. Determine the mass of the H2CO, produced

B. Calculate the percentage yield of H.CO, for the reaction. Show your work or describe the calculation process in detail.

What is the density of a compound whose mass = 5.51001 g, and volume = 5.010 L? The formula for density is d = mass/volume

A student calculated the molarity of a solution prepared by dissolving 0.730 mol of table sugar (sucrose, C₁₂H₂₂O₁₁) in 1.8x10^3 mL of water as 4.06x10^-4 M C₁₂H₂₂O₁₁. 

• Explain the student's calculation error and explain how the student should solve for the correct value of molarity. Show a valid calculation for the molarity.

II. The student then takes a 1.00 M stock solution of table sugar (sucrose, C₁₂H₂₂O₁₁) and mixes 0.305 L of stock solution with additional distilled water to create a dilute solution with a total volume of 1.25 L. 

• Explain how the student can determine the molarity of the resulting solution. Show a valid calculation for the final molarity.

A sample of an oxide of vanadium weighing 4.589 g was reduced with hydrogen gas to form water and another oxide of vanadium weighing 3.782 g. The second oxide was reduced further with hydrogen gas until only 2.573 g of vanadium metal remained. Write down balanced reaction equations for the two reduction reactions above.