Chemistry Answers

Explain why different products are obtained in the electrolysis of molten

potassium iodide and in the electrolysis of aqueous solution of potassium iodide

A buffer system is prepared by mixing 2 mols of HF(aq) (Ka=7.1 x 10^-4) and 1.8 moles NaF(aq) in a 500 mL solution. A) calculate the pH of the buffer. B) calculate the pH of the buffer after adding 0.2 mols of HCl. C) calculate the pH of the buffer after adding 0.3 mols LiOH

25.0 mL of 0.100 M HC2H3O2 is titrated by a 0.100 M NaOH. A) Write the net ionic equation. B) calculate the pH of the solution after adding 10 mL of NaOH

Write a balanced chemical equation of the decomposition of glucose.

Dinitrogen pentaoxide, N₂O5, decomposes to nitrogen dioxide, NO2 and oxygen, O₂ as shown in the reaction below: 2N₂O5(g) →→→ 4NO2(g) + O₂(g) Initial rate decomposition data at 25° C for the decomposition give the following data: Concentration of N₂O5, M Initial rate, mol/L-min 0.250 5.70 x 10-4 0.350 7.98 x 10-4 0.450 1.03 x 10-3 Calculate the rate constant at 25°C ? min-¹ What is the half-life for the reaction at 25°C ? min How long will it take to decompose 40.0% of N₂O5 at 25°C ? min At 40°C, the rate constant for the decomposition is 1.58 x 10-2 min¹. What is the activation energy for this reaction? kJ/mol

What is the expression for Kc for this reaction?

[1] Kc= [Cl2] ² / [TiCl₄]

[2] Kc= [TiCl₄] / [Ti][Cl₂] ²

[3] Kc= 1 / [Cl2] 2

[4] Kc= [TiCl₄] / [Cl₂]

[5] All of the above.

How many moles of gas are there in a sample occupying 1.74 L at 0.136 atm and 25°C? [1] 0.00968 mol

[2] 0.0463 mol

[3] 0.0926 mol

[4] 7.36 mol

[5] None of the above 

What is the density of CO2 at 25°C and 750 Torr?

[1] 0.472 g/L [2] 1.78 g/L

[3] 1.82 g/L

[4] 2.12 g/L

[5] None of the above 

A flask of 7L contains a mixture of 6g of O2 and 15g of N2 at 30°C.What is the partial pressure of the oxygen gas?

[1] 0.67 atm

[2] 1.9 atm

[3] 2.59 atm

[4] 22.1 atm

[5] None of the above