- Quiz (2): Second year student, Chemistry-Physics group
- A mass of 1.225 g of sodium oxalate (MW = 134.00 mg/mol) is placed in a 100.0 mL volumetric flask. A 10.00 mL aliquot is placed in 100 mL of water and titrated with 32.99 mL of potassium permanganate.
- Show the reaction equation between potassium permanganate and sodium oxalate.
(4)
- What is MKMnO4?
(8)
- Write balanced net ionic equations for the following reactions. Identify the oxidation and reduction for each reaction.
- Cl- + MnO2(s) ==== Cl2(g) + Mn2+
(6)
- IO3- + I- === I2(aq)
(6)
- IO3- + I- + Cl- === ICl2-
(6)
- I2 + H2S === I- + S(s)
(6)
- A solution contains 9.00% (w/w) NaOH (MW = 40.0 g) and has a density of 1.098g/mL. 20 mL of this solution is diluted to 500 mL.
- a) Calculate the pH of the final, diluted solution. (pH = ............... )
6
b) BONUS: Calculate the pH of the original solution before it was diluted. Assume complete dissociation. Be careful. Think!! ( pH = .............)
3
- Calculate the molar concentration of H3O+in the final solution prepared by dissolving 5.36 g of benzoic acid C6H5COOH --- (MW = 122.1 g/mol)--- in 100 mL of water and diluting 20 mL of this solution to 500 mL, and finally diluting 50 mL of this to 250 mL. (H3O+ = ................ M)
7
- What weight of sodium acetate (MW = 82.03 g/mol) must be added to 600 mL of 0.800 M acetic acid to produce a buffer with a pH of 5.00? ( ..................... g)
8
- A 12.5% (w/w) NiCl2 (MW=129.61 g/mole) solution has a density of 1.149 g/mL. Calculate.
- The molar concentration of NiCl2 in this solution,
8
- The mass in grams of NiCl2 contained in each liter of this solution
2
- Ten milliliters of a 0.1123 M solution of HCl is diluted in a 100.0 mL volumetric flask. A solution containing sodium hydroxide (MW=40.00 g/mol) requires 5.76 mL of the dilute HCl for neutralization. How many milligrams of NaOH are in the sodium hydroxide solution?
5
- What Na2CO3 mass (MW=105.9 g/mole) is required to neutralize 22.31 mL of 0.1017 M HCl.
5
- 2.5543 grams of Na2CO3 (MW=105.9 g/mole) are placed in a 500.0 mL volumetric flask. A 25.00 mL aliquot of this solution is neutralized with 17.55 mL of HCl. What is the molarity of the HCl solution