Physical Chemistry Answers

Think about a problem you have seen in your community. How could your understanding of the properties of matter help you solve this problem

A solution made from pure Potassium hydroxide contained 1.85 g of Potassium

hydroxide in exactly 200 cm 3 of water. Using phenolphthalein indicator, titration of 20.0

cm 3 of this solution is carried out v/s sulphuric acid. 9.35 cm 3 of sulphuric acid solution is

required for complete neutralisation. [atomic masses: K= 39, O = 16, H = 1]

(a) write the equation for the titration reaction.

(b) calculate the molarity of the Potassium hydroxide solution.

(c) calculate the moles of Potassium hydroxide neutralised.

(d) calculate the moles of sulphuric acid neutralised.

(e) calculate the molarity of the sulphuric acid.

The enthalpy changes of CO2(g) and H2O(l) under standard conditions are 394.65 kJ/mol and 285.84 kJ/mol, respectively. If the enthalpy change of combustion of acetaldehyde (CH3CHO) is 1167.62 kJ/mol, find its standard enthalpy change of formation, o Hf .

Given that the molar mass of argon gas is39.95 g/mil,if 2.00 mil of argon can effuse from an opening in a vessel in 3.626 seconds and 1.00 mols of gas X can effuse in 1.000 seconds.identify gas X

⦁ Which of these 2 reactions occur with the greater increase in entropy? Explain your reasoning.

Reaction 1: 2NO(g) → N2(g) + O2(g)

Reaction 2: Br2(g) + Cl2(g) → BrCl(g)

For a particular chemical reaction, the free energy changes at 25 o C and 35 o C are -

33.089kJ and -28.018kJ respectively. Calculate the heat of reaction.