General Chemistry Answers

Oxygen gas is collected at a pressure of 123 kPa in a container which has a volume of 10.0 L. What temperature must be maintained on 0.500 moles of this gas in order to maintain this pressure? 

Which solution would have the greatest freezing point depression?

a. 0.10m CH₃OH

b. 0.10m Na₂S

c. 0.10m NaCl

d. 0.10m KCl

A 25 cm3 sample of an aqueous solution of barium hydroxide, of concentration 0.146 mol dm3 was exactly neutralized by 28.7cm3 of aqueous nitric acid, according to the unbalanced equation:

Ba (OH)2 (aq) + HNO3(aq) ˗˗˗˗˗˗˗˗˃ Ba(NO3)2 (aq) + H2O (l)

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

How many grams of beryllium chloride (BeCl₂) are needed to make 250mL of a 1.5M solution?

Consider the following balanced redox reaction Mn2+(aq) + S2O82–(aq) + 2H2O(l) → MnO2(s) + 4H(aq) + 2SO42–(aq)

Which of the following statements is true? A. Mn2+(aq) is the oxidizing agent and is reduced. B. Mn2+(aq) is the oxidizing agent and is oxidized. C. Mn2+(aq) is the reducing agent and is oxidized. D. Mn2+(aq) is the reducing agent and is reduced. E. Manganese does not change its oxidation number in this reaction.

Which one of the following is not a redox reaction? A. Al(OH)4(aq) + 4H(aq) → Al3+(aq) + 4H2O(l) B. C6H12O6(s) + 6O2(g) → 6CO2(g) + 6H2O(l) C. Na6FeCl8(s) + 2Na(l) → 8NaCl(s) + Fe(s) D. 2H2O2(aq) → 2H2O(l) + O2(g) E. CO2(g) + H2(g) → CO(g) + H2O(g)

'A' reacts with 'B' in a one-step reaction to give 'AB'. The rate constant for the reaction is 2.0 x 10-3 L mole-1 sec-1 and neither A or B are 0th order. If the concentration of A is increased from 0.50 mole/L to 1.0 mole/L, what effect would this have on the rate of the reaction? Explain your answer.

To neutralize 100 g of HNO3 solution, 30 cm3 of 15% NaOH solution with a density of 1.15 g / cm3 was used. Calculate the mass fraction (in%) of nitric acid in the solution!

A sample of Oxygen gas has a volume of 8.40 L at a pressure of 105 kPa. What will the new volume of the gas be at a pressure of 205 kPa?

If 4 moles of NH₃ (ammonia) and 3 moles of O₂ (oxygen gas) react in the reaction below, determine the EXCESS reactant. 4NH₃ + 5O₂ --> 4NO + 6H₂O