General Chemistry Answers

An experimental data on the reaction of H₂ and PO₃^-3 is given below:

Initial [PO₃^-3]

Initial [H₂]

Initial Rate

Experiment 1

0.100

0.100

1.50

Experiment 2

0.200

0.100

3.00

Experiment 3

0.100

0.200

6.00

a) What is the order of reaction with respect to [PO₃^-3]?

b) What is the order of reaction with respect to [H₂]?

c) What is the overall reaction?

A solution is prepared at 20^oC and its concentration is expressed in two different units; Molarity and Molality. The solution is then heated to 88^oC. Which of the concentration units will change? 

Calculate the voltage that would result if the following half-cells were combined. Identify which reaction is oxidation and which is reduction. Also label the anode and the cathode.

• Zn ⟶ Zn²⁺ + 2e-

Cu ⟶Cu²⁺ + 2e-

• Au ⟶ Au³⁺ + 3e-

Ag ⟶ Ag⁺ + 1e-

What is the pH of a buffer made up of 0.5M NH3 and 0.456M NH4CI? pKb NH3= 4.74

1. What is the pH of a solution with [H^ + ] of 1.0*10^ -9 M? What is its pOH? (Kw=[H^ + ][OH^ - ])

2. The [H3O^ + ] of a solution is 1.3 x 10 ^ - 5 , Calculate the [OH^ - ], pH and pOH of the solution. Is the solution acidic or basic?

3. The pH of a solution is 8.7. What are the pOH, [H3O^+] and [OH^-] of the solution?

Balance the following redox reaction using the half-reaction method.

Fe2+(aq)+Cr2072-(aq)->Fee+(aq)+Cr3+(aq)

Is the reactant undergoing oxidation or reduction in each of the following incomplete chemical equations? Justify your answer.

1. SnO2 → SnO
2. C6H6 → C6H12
3. KClO3 → KCl
4. NO → NO2
5. MnO4-2 → MnO4-

Balance the following redox reaction that takes place in an acidic solution using the oxidation number method: Fe203(s)+CO(g)-Fe3(aq)+Cr3+(aq)

A 4.00 * 102 g piece of iron at 22.0°C is heated in a bomb calorimeter until the temperature is 250.0°C. If the iron absorbs 41.04 kJ of heat, what is the specific heat capacity of the iron?

Average salinity of coastal waters of Cyprus is 39.1 psu Calculate the salinity in: a) percentage, b) ppt c) ppm d) molarity (Assume that salinity is due to dissolved NaCl, and the density of Mediterranean sea is 1.05 g/mL) (psu: Practical salinity unit, 1 psu = 1g/kg, MNAC= 58.4 g/mol) Ans: a) 0.39%, b) 39.1 ppt, c) 39000 ppm, d) 1.568 M Ans: a) 3.91%, b) 39.1 ppt, c) 39100 ppm, d) 0.71 M ...