Analytical Chemistry Chemistry - Analytical Chemistry

Assertion (A): In chromatography, the separation of components is based on their different affinities for the stationary and mobile phases.
Reason (R): Components with a higher affinity for the stationary phase move slower than those with a higher affinity for the mobile phase.

Assertion (A): The addition of hydrochloric acid to a solution containing carbonate (CO₃^2-) ions results in effervescence.
Reason (R): Carbonate ions react with hydrochloric acid to produce carbon dioxide gas, which causes the effervescence.

Assertion (A): The flame test for sodium (Na⁺) cation shows a bright yellow colour.
Reason (R): Sodium ions emit yellow light when heated or come under light.

A hydroxide of metal, which is soluble in conc. sodium hydroxide solution is:

Which salt solution will form a deep blue coloration when treated with excess of NH₄OH solution?

Name the probable cation present.
(a) Reddish brown precipitate insoluble in sodium hydroxide.
(b) Gelatinous white precipitate soluble in excess of ammonium hydroxide.

State giving observations.
(a) What happens when calcium carbonate reacts with dilute HCl?
(b) What happens when we add ammonium hydroxide to calcium salts, explain?

(a) Define Amphoteric oxide.
(b) Write atleast one example of Amphoteric oxide and also state the chemical equations involved.

State the observations.
(i) Copper sulphate crystals when heated in excess.
(ii) What happens when excess of sodium hydroxide is added to copper sulphate solution?

State one relevant observation for each of the following reactions :
(i) Ammonium hydroxide solution is added to zinc nitrate solution in minimum quantities and then in excess.
(ii) Action of Sodium hydroxide solution on ferrous sulphate solution.
(iii) Lead nitrate solution is treated with sodium hydroxide solution drop wise till it is in excess.

State one relevant observation for each of the following reactions :
(i) Excess of ammonium hydroxide solution is added to lead nitrate solution.
(ii) Sodium hydroxide solution is added to ferric chloride solution at first a little and then in excess.
(iii) Ammonium hydroxide solution is added to copper (II) nitrate solution in small quantities and then in excess.

(a) Distinguish between Qualitative and Quantitative analysis.
(b) Define Reagent
(c) Define Precipitate

In a chemistry lab, a student is given a solution containing an unknown cation. The student adds sodium hydroxide (NaOH) to the solution and observes the formation of a blue precipitate. The student then decides to add ammonium hydroxide to a fresh sample of the solution in excess.
(a) Identify the cation.
(b) What happens when excess of NaOH is added in the solution?
(c) What happens when excess of ammonium hydroxide is added to the solution?

A student performs an experiment to identify an unknown cation present in a solution. The student adds a few drops of sodium hydroxide (NaOH) to the solution and observes the formation of a chalky white precipitate. When an excess of NaOH is added, the precipitate dissolves, forming a clear solution.
(a) Identify the cation.
(b) Write the balanced chemical equation for the reaction that leads to the formation of the white precipitate.
(c) What happens to the white precipitate when an excess of NH₄OH is added?

Name the cation that gives a blue precipitate with sodium hydroxide (NaOH) which does not dissolve in excess NaOH.

Name the cation that produces a violet flame in a flame test.

Name the cation that forms a red precipitate with sodium hydroxide (NaOH) which is soluble in excess NaOH.

Name the cation that gives a white precipitate with dilute hydrochloric acid but is soluble in excess ammonia.

Name the cation that forms a deep blue complex with ammonia (NH3).

________ chromatography is a technique used to separate components of a mixture based on their different interactions with a stationary phase and a mobile phase.

pOH of the solution is the measure of indication of ________ concentration in the solution.

During titration between oxalic acid with sodium hydroxide the endpoint of the solution is ________.

Ferrous sulphate on reaction with concentrated nitric acid turns reddish brown the reaction occuring here is ________.

Consider the reactions:
• Lead salt when reacts with sodium hydroxide
• Lead salts when reacts with ammonium hydroxide
(i) What happens when excess of sodium hydroxide is added to lead salt.
(ii) What colour precipitate is formed when sodium or ammonium hydroxide reacts with lead salt.
(iii) Which acid is used to dissolve chalky white precipitate of lead salt.
(iv) State the observation, when lead salt reacts with excess of ammonium hydroxide.

Consider a reaction
A - Aluminium metal when treated with sodium hydroxide
B - Aluminium oxide when reacts with sodium hydroxide
(i) What is the common product formed when aluminium metal and Aluminium oxide reacts with sodium hydroxide.
(ii) Which gas is released when aluminium metal reacts with sodium hydroxide.
(iii) Write the chemical equation involved when aluminium oxide reacts with sodium hydroxide.
(iv) What is the colour of the main product formed by aluminium metal and Aluminium oxide when reacted with sodium hydroxide.

You are provided with a colorless, aqueous solution suspected to contain one or more of the following anions:
chloride (Cl^-), sulphate (SO₄^2-), and nitrate (NO₃^-).
Outline the steps you would take to identify which anion(s) are present in the solution. Describe the reagents you would use, the expected observations, and the chemical equations for any reactions that occur.

A local water treatment plant is responsible for ensuring that the water supplied to the community is safe for consumption. Recently, there have been complaints about the taste and odor of the water. The plant decided to conduct a comprehensive water quality analysis to address these concerns. The analysis includes measuring pH, chlorine content, total dissolved solids (TDS), and detecting the presence of any heavy metals.
The results from the analysis are as follows: pH: 7.2
Chlorine Content: 0.8 ppm
TDS: 450 mg/L
Heavy Metals Detected: Trace amounts of lead (Pb) and arsenic (As)
(i) Evaluate the pH level of the water. Is it within the safe range for drinking water? Explain.
(ii) Discuss the significance of chlorine content in the water. Is the measured chlorine content within the acceptable limits?
(iii) Propose methods the water treatment plant could use to address the presence of heavy metals detected in the water.
(iv) What additional tests or analyses would you recommend to ensure comprehensive water quality assessment?

You are provided with two separate colorless solutions. Solution A is suspected to contain either silver (Ag⁺) or copper(II) (Cu²⁺) ions, Solution B is suspected to contain either sulfate (SO₄^2-) or carbonate (CO₃^2-) ions.
Design a step-by-step procedure to identify the ions present in both solutions, detailing the reagents you would use, the observations you would expect, and the chemical equations for the reactions involved.

Sodium hydroxide solution is added in excess to the solutions of cations shown in column A. The colour of ppt. formed are shown in column B. Match the ions with there precipitates.

Column A	Column B
(a) Pb2+	1. Reddish brown
(b) Fe2+	2. White insoluble in excess
(c) Zn2+	3. Dirty green
(d) Fe3+	4. White gelatin like soluble in excess
	5. White (chalky) soluble in excess