Physical Chemistry Answers

When 50 ml water sample titrated against 0.02 N HCl acid using phenolphthalein

indicator, the titration reading was 24.2 ml. After boiling 100 ml of the same sample using

methyl orange indicator, the titration value was 28.2 ml. Calculate permanent and total hardness.

According to the following reaction, how many moles of calcium carbonate are necessary to form 0.194 moles carbon dioxide?

calcium carbonate (s) calcium oxide (s) + carbon dioxide (g)

How many grams of HF can be prepared if 75.0 g of H2SO4 and 63.0 g of CaF2 are used? (Hint: must find which is the limiting reagent

a)Write an expression for the solubility product,Ksp for Calcium Sulphate

b)The solubility product of Calcium Sulphate is 2×10^-5 mol^2dm^-6 at 25°C

Predict whether precipitation would occur if equal volumes of 1×10^-2 moldm^-3 CaCl2 and 1×10^-2 moldm-3 Na2SO4 mixed

0.15 mol NaCl in 1.4 L h20

100g of an unknown metal at 150°C was dropped into a bucket containing 50g of water initially at 21°C.The final temperature of the mixture was 32°C.What is the specific heat capacity of the unknown metal?

Consider the appended paper that discusses the mechanism of the palladium-catalysed carbonylation of 4-iodoanisole A to afford ethyl 4-methoxybenzoate B shown below (J. Am. Chem. Soc. 2010, 132, 3153-3158) and answer ALL the following parts (i) to (v).  

How is the palladium(II) pre-catalyst reduced to Pd(0) in this carbonylation (your answer should include a description of the fundamental steps).

 Propose a structure for the pre-catalyst generated from the reaction between PdCl2(MeCN)2 and (E)-3-(2)-(diphenylphosphino)-1-phenyl-prop-2-en-1-one (L1) and suggest what spectroscopic methods would be most suitable for its characterisation and explain why.  

A liquid sample was made by adding 4 mL of concentrated (14 M) hydrochloric acid (HCl) into 2 litres of pure water. What is the pH value of the resulting sample? Assuming that there are no other acids or base presented in the water, and 100% of hydrochloric acid was dissociated.

Topic: Electrode Potential and Electrochemical Cells

Question 2

several different electrochemical cells can be constructed using the materials listed below.

1.0 M solution of AI(NO₃)₃, Fe(NO₃)₂ and Cu(NO₃)₂

metal strips of Al, Cu and Fe

salt bridge material and solution

• Cathode (Reduction) Haf-Reaction Al⁺³ (aq) + 3e^- —> AI(s) , Standard Potential E^o (volts) -1.66.

• Cathode ( Reduction) Half-Reaction Fe²⁺ (aq) + 2e^- —> Fe(s) , Standard Potential E^o (Volts) -0.41.
  
• Cu²⁺ (aq) + 2e^- —> Cu(s) , Standard Potential E^o (volts) +0.34.

a) write the balanced ionic equation for the reaction that occurs in the cell that would have the greatest positive value of E_cell (1 mark)

b) Calculate the standard cell potential E^o_cell for the reaction written in part (a). ( 2 marks)

please answers all the question with detailed explanation and with steps please please 🙏🏾 🙏🏾

Topic: Electrode Potential and Electrochemical Cells

question 1

The diagram below shows the experiment setup for a typical electrochemical cell that contains two standard half cells. The cell operates according to the reaction represented by the following equation

Zn(s) + Ni²⁺ (aq) —> NI(s) + Zn²⁺ (aq)

a) identify M and M²⁺ in the diagram? ( marks)

b) indicate which of the metal electrodes in the cathode. Write the balanced equation for the reaction that occurs in the half-cell containing the cathode. (2 marks).

c) Describe what would happen in the cell voltage if the said bridge was removed. Explain the reason for this. ( 2 marks)

please answers all the questions and with detailed answers with explanation please 🙏🏾🙏🏾🙏🏾🙏🏾🙏🏾