Qualitative analysis is used to identify the cations and anions present in an unknown chemical substance. Cations such as sodium, calcium, and ammonium can be identified using sodium hydroxide and ammonia solutions. Anions like chloride, nitrate, and sulfate can be identified through chemical tests involving silver nitrate, sodium hydroxide with aluminum foil, and barium chloride solutions respectively. These tests produce characteristic precipitates or gas emissions to reveal the ions present. Dilute nitric acid is first added to remove any interfering carbonate ions.
CHAPTER 6 : ACID, BASE AND SALT
CHEMISTRY FORM 4 KSSM
1. SALTS, CRYSTALS AND PHYSICAL PROPERTIES OF SALTS
2. PRODUCE SOLUBLE SALT THROUGH THE REACTION BETWEEN
a. ACID AND ALKALI
b. ACID AND METAL OXIDE
c. ACID AND REACTIVE METAL
d. ACID AND METAL CARBONATE
3. PURIFICATION OF IMPURE SALTS THROUGH RECRYSTALLISATION METHOD
4. PRODUCE INSOLUBLE SALT THROUGH DOUBLE-DECOMPOSITION REACTION (PRECIPITATION REACTION)
CHEMISTRY : ACIDS,BASES AND SALTS:
1.definition and characteristics of salts,
2. preparation of salts and,
3. types of salts,
4.uses and
5.hydrolysis of salt in water
CHAPTER 6 : ACID, BASE AND SALT
CHEMISTRY FORM 4 KSSM
1. SALTS, CRYSTALS AND PHYSICAL PROPERTIES OF SALTS
2. PRODUCE SOLUBLE SALT THROUGH THE REACTION BETWEEN
a. ACID AND ALKALI
b. ACID AND METAL OXIDE
c. ACID AND REACTIVE METAL
d. ACID AND METAL CARBONATE
3. PURIFICATION OF IMPURE SALTS THROUGH RECRYSTALLISATION METHOD
4. PRODUCE INSOLUBLE SALT THROUGH DOUBLE-DECOMPOSITION REACTION (PRECIPITATION REACTION)
CHEMISTRY : ACIDS,BASES AND SALTS:
1.definition and characteristics of salts,
2. preparation of salts and,
3. types of salts,
4.uses and
5.hydrolysis of salt in water
Online learning to understand the concept and application of chemicals on the topic of salt. These slides were uploaded to help students understand the basic concepts of chemistry. Independent study in Freestyle.com
Revision Slides for AQA A-Level Chemistry on the Group Two Elements. Designed for the new Exam Series of June 2017, but relevant for all series and exam boards.
more chemistry contents are available
1. pdf file on Termmate: https://www.termmate.com/rabia.aziz
2. YouTube: https://www.youtube.com/channel/UCKxWnNdskGHnZFS0h1QRTEA
3. Facebook: https://web.facebook.com/Chemist.Rabia.Aziz/
4. Blogger: https://chemistry-academy.blogspot.com/
Oxyacids of sulphur are sulphur, hydrogen and oxygen containing compounds. Oxyacids of sulphur are sulphurous acid, sulphuric acid, peroxomonsulphuric acid, peroxodisulphuric acid, thiosulphuric acid, dithionous acid, dithionic acid, polythionic acid and pyrosulphuric acid.
The NO2 group attached with organic chain is called as nitro functional group. All the compounds containing the nitro functional group are called as organic nitro compounds.
Online learning to understand the concept and application of chemicals on the topic of salt. These slides were uploaded to help students understand the basic concepts of chemistry. Independent study in Freestyle.com
Revision Slides for AQA A-Level Chemistry on the Group Two Elements. Designed for the new Exam Series of June 2017, but relevant for all series and exam boards.
more chemistry contents are available
1. pdf file on Termmate: https://www.termmate.com/rabia.aziz
2. YouTube: https://www.youtube.com/channel/UCKxWnNdskGHnZFS0h1QRTEA
3. Facebook: https://web.facebook.com/Chemist.Rabia.Aziz/
4. Blogger: https://chemistry-academy.blogspot.com/
Oxyacids of sulphur are sulphur, hydrogen and oxygen containing compounds. Oxyacids of sulphur are sulphurous acid, sulphuric acid, peroxomonsulphuric acid, peroxodisulphuric acid, thiosulphuric acid, dithionous acid, dithionic acid, polythionic acid and pyrosulphuric acid.
The NO2 group attached with organic chain is called as nitro functional group. All the compounds containing the nitro functional group are called as organic nitro compounds.
Qualitative analysis of group 4 cationsJessa Arino
The Group IV cations are Ba2+, Sr2+, Ca2+.
These metals form chlorides, sulfides and hydroxides that are soluble under that prevail in the precipitations of Group I, II, and III.
In this laboratory exercise we will separate and identify Cations dissolved in an Aqueous system. Since we will not quantify the amount of each Cation present, but instead merely discern its presence, such a scheme for separation and identification is referred to as a Qualitative Analysis. In our particular case, we will be testing for the presence of the following nine Cations:
Ag+, Pb2+, Cu2+, Bi3+, Fe3+, Mn2+, Ni2+, Ba2+, Na+
This is a presentation by Dada Robert in a Your Skill Boost masterclass organised by the Excellence Foundation for South Sudan (EFSS) on Saturday, the 25th and Sunday, the 26th of May 2024.
He discussed the concept of quality improvement, emphasizing its applicability to various aspects of life, including personal, project, and program improvements. He defined quality as doing the right thing at the right time in the right way to achieve the best possible results and discussed the concept of the "gap" between what we know and what we do, and how this gap represents the areas we need to improve. He explained the scientific approach to quality improvement, which involves systematic performance analysis, testing and learning, and implementing change ideas. He also highlighted the importance of client focus and a team approach to quality improvement.
Welcome to TechSoup New Member Orientation and Q&A (May 2024).pdfTechSoup
In this webinar you will learn how your organization can access TechSoup's wide variety of product discount and donation programs. From hardware to software, we'll give you a tour of the tools available to help your nonprofit with productivity, collaboration, financial management, donor tracking, security, and more.
Synthetic Fiber Construction in lab .pptxPavel ( NSTU)
Synthetic fiber production is a fascinating and complex field that blends chemistry, engineering, and environmental science. By understanding these aspects, students can gain a comprehensive view of synthetic fiber production, its impact on society and the environment, and the potential for future innovations. Synthetic fibers play a crucial role in modern society, impacting various aspects of daily life, industry, and the environment. ynthetic fibers are integral to modern life, offering a range of benefits from cost-effectiveness and versatility to innovative applications and performance characteristics. While they pose environmental challenges, ongoing research and development aim to create more sustainable and eco-friendly alternatives. Understanding the importance of synthetic fibers helps in appreciating their role in the economy, industry, and daily life, while also emphasizing the need for sustainable practices and innovation.
We all have good and bad thoughts from time to time and situation to situation. We are bombarded daily with spiraling thoughts(both negative and positive) creating all-consuming feel , making us difficult to manage with associated suffering. Good thoughts are like our Mob Signal (Positive thought) amidst noise(negative thought) in the atmosphere. Negative thoughts like noise outweigh positive thoughts. These thoughts often create unwanted confusion, trouble, stress and frustration in our mind as well as chaos in our physical world. Negative thoughts are also known as “distorted thinking”.
Operation “Blue Star” is the only event in the history of Independent India where the state went into war with its own people. Even after about 40 years it is not clear if it was culmination of states anger over people of the region, a political game of power or start of dictatorial chapter in the democratic setup.
The people of Punjab felt alienated from main stream due to denial of their just demands during a long democratic struggle since independence. As it happen all over the word, it led to militant struggle with great loss of lives of military, police and civilian personnel. Killing of Indira Gandhi and massacre of innocent Sikhs in Delhi and other India cities was also associated with this movement.
The Indian economy is classified into different sectors to simplify the analysis and understanding of economic activities. For Class 10, it's essential to grasp the sectors of the Indian economy, understand their characteristics, and recognize their importance. This guide will provide detailed notes on the Sectors of the Indian Economy Class 10, using specific long-tail keywords to enhance comprehension.
For more information, visit-www.vavaclasses.com
How to Create Map Views in the Odoo 17 ERPCeline George
The map views are useful for providing a geographical representation of data. They allow users to visualize and analyze the data in a more intuitive manner.
2. What is Qualitative Analysis?
Qualitative analysis is a
process used to determine and
identify the chemical
properties of an unknown
substance.
In your syllabus, the analysis
will be used to identify the
cations and anions present in
an unknown chemical.
3. What are Cations?
A cation is a positively charged ion.
For example, sodium ion (Na+
) and
ammonium ion (NH4
+
) are cations.
4. What are Anions?
An anion is a negatively charged ion.
For example, chloride ion (Cl-
) and
nitrate ion (NO3
-
) are anions.
5. Salts are ionic compounds.
All salts are ionic compounds and they contain both
cations and anions.
For example, sodium chloride is made up of sodium
ion (cation) and chloride ion (anion).
We can identify the cations and anions in the salt by
adding certain reagents (chemicals).
6. Tests for Anions
Anion How to test? Observations if anion is
present
Nitrate
NO3
-
Add aqueous sodium
hydroxide, then add
aluminium foil and warm
the mixture.
A colourless and pungent
gas which turns moist red
litmus blue is produced.
The gas is ammonia (NH3
).
Carbonate
CO3
2-
Add any dilute acid. Effervescence is observed.
The gas given off forms
white precipitate with
limewater.
The gas is carbon dioxide
(CO2
).
7. Tests for Anions
Chloride
Cl-
Add dilute nitric acid,
then add aqueous silver
nitrate.
White precipitate of silver
chloride (AgCl) is formed.
Iodide
I-
Add dilute nitric acid,
then add aqueous lead
(II) nitrate.
Yellow precipitate of lead
(II) iodide (PbI2
) is formed.
Sulfate
SO4
2-
Add dilute nitric acid,
then add aqueous
barium nitrate
or
Add dilute hydrochloric
acid, then add aqueous
barium chloride
White precipitate of barium
sulfate (BaSO4
) is formed.
White precipitate of barium
sulfate (BaSO4
) is formed.
8. Question to ponder…
Why is dilute nitric acid added before
adding aqueous silver nitrate/ lead (II)
nitrate/ barium nitrate?
9. Question to ponder…
Why is dilute nitric acid added before adding aqueous
silver nitrate/ lead (II) nitrate/ barium nitrate?
This is to remove any carbonate ions that may be
present in the solution which will form insoluble
salts (precipitate) with the reagents added.
Remember that most carbonates are insoluble!
10. Tests for Cations
Cations can be identified by adding aqueous
sodium hydroxide and aqueous ammonia.
Most cations (except H+
, Na+
, K+
and NH4
+
) give
precipitates (insoluble salts) with these
alkalis.
11. Tests for Cations
Ca2+
Cation Effect on adding
aqueous sodium
hydroxide, NaOH (aq)
Effect on adding
aqueous ammonia,
NH4
OH (aq)
Calcium
Ca2+
White precipitate of
calcium hydroxide,
Ca(OH)2
is formed.
Precipitate is insoluble in
excess sodium
hydroxide.
No precipitate formed.
12. Tests for Cations
Aluminium
Al3+
White precipitate of
aluminium hydroxide,
Al(OH)3
is formed.
Precipitate is soluble in
excess sodium hydroxide to
give a colourless solution.
White precipitate of
aluminium hydroxide,
Al(OH)3
is formed.
Precipitate is insoluble in
excess aqueous ammonia.
Lead (II)
Pb2+
White precipitate of lead (II)
hydroxide, Pb(OH)2
is
formed.
Precipitate is soluble in
excess sodium hydroxide to
give a colourless solution.
White precipitate of lead (II)
hydroxide, Pb(OH)2
is
formed.
Precipitate is insoluble in
excess aqueous ammonia.
13. Tests for Cations
Al3+
and Pb2+
give the same observations with aqueous
sodium hydroxide and aqueous ammonia.
How to distinguish them?
Add aqueous potassium iodide (KI)!
If Pb2+
is present, a bright yellow precipitate of lead
(II) iodide (PbI2
) will be formed.
Al3+
will not give precipitate with potassium iodide.
14. Tests for Cations
Copper
(II)
Cu2+
Blue precipitate of
copper(II) hydroxide,
Cu(OH)2
is formed.
Precipitate is insoluble in
excess sodium hydroxide.
Blue precipitate of
copper(II) hydroxide,
Cu(OH)2
is formed.
Precipitate is soluble in
excess aqueous ammonia
to give a deep blue
solution.
Iron (II)
Fe2+
Green precipitate of iron(II)
hydroxide, Fe(OH)2
is
formed.
Precipitate is insoluble in
excess sodium hydroxide.
Green precipitate of iron(II)
hydroxide, Fe(OH)2
is
formed.
Precipitate is insoluble in
excess aqueous ammonia.
On standing, the green Fe(OH)2
precipitate oxidises to form red-brown
Fe(OH) precipitate.
15. Tests for Cations
Iron (III)
Fe3+
Red brown precipitate of
iron(III) hydroxide, Fe(OH)3
is formed.
Precipitate is insoluble in
excess sodium hydroxide.
Red brown precipitate of
iron(III) hydroxide, Fe(OH)3
is formed.
Precipitate is insoluble in
excess aqueous ammonia.
Zinc
Zn2+
White precipitate of zinc
hydroxide, Zn(OH)2
is
formed.
Precipitate is soluble in
excess sodium hydroxide
to give a colourless
solution.
White precipitate of zinc
hydroxide, Zn(OH)2
is
formed.
Precipitate is soluble in
excess aqueous ammonia
to give a colourless
solution.
16. Tests for Cations
Ammoni
um
NH4
+
No precipitate is formed.
On heating, a gas which
turns moist red litmus blue
is produced. The gas is
ammonia.
---
17. Tests for Cations
Note that Al3+
and Pb2+
can be distinguished by adding
aqueous potassium iodide (KI).
If Pb2+
is present, a bright yellow precipitate of lead (II)
iodide (PbI2
) will be formed.
H+
(acid) can be identified by adding carbonate.
Carbon dioxide gas will be produced.
K+
and Na+
ions do not form any precipitate as all their
salts are soluble.
22. Tests for Water
There are 2 chemical tests to detect the presence of
water or water vapour:
Use anhydrous copper (II) sulfate
Water will change the colour of anhydrous copper (II)
sulfate from white to blue.
Use dry cobalt (II) chloride paper
Water will change the colour of dry cobalt (II) chloride
paper from blue to pink.
23. Important Concepts for QA
Important Reactions from Acids, Bases & Salts
Acid + metal → salt + hydrogen
Acid + metal oxides/ hydroxide (base) → salt + water
Acid + carbonate → salt + water + carbon dioxide
Alkali + ammonium salt → salt + water + ammonia
24. Decomposition by heat (1)
Some metal carbonates are decomposed by
heat to form metal oxides & carbon dioxide.
Eg: copper (II) carbonate is decomposed by heat to
form copper (II) oxide and CO2.
CuCO3 (s) CuO (s) + CO2 (g)
25. Decomposition by heat (2)
Most metal nitrates (except Group I) decompose to
form metal oxides, nitrogen dioxide and oxygen gas.
Eg: decomposition of calcium nitrate
2 Ca(NO3)2 (s) 2 CaO (s) + 4 NO2 (g) + O2 (g)
Nitrogen dioxide, NO2, is a brown gas. It can be seen as
brown fumes given off during the heating of solid metal
nitrates.
26. Decomposition by heat (2)
Group I metal nitrates decompose to form metal
oxides and oxygen only. No brown nitrogen dioxide
gas is given off.
27. Confusion…
Ammonia (NH3) is an alkaline gas that turns
moist red litmus blue.
Aqueous ammonia (NH4OH) is a weak alkali
that is used to test for cations.
Ammonium (NH4
+
) is a cation found in
ammonium salts & aqueous ammonia.
28. White Precipitate in Cation Test
When asked to identify white precipitate when sodium
hydroxide/aqueous ammonia is added, look out for Zn2+
,
Ca2+
, Pb2+
and Al3+
.
Zn2+
is the only cation that forms white precipitate that is
soluble in excess in both sodium hydroxide and aqueous
ammonia.
Ca2+
is the only cation that forms white precipitate that is
insoluble in excess NaOH.
29. Solubility of Salts
All nitrates are soluble.
Most chlorides are soluble except silver chloride and lead
(II) chloride.
Most sulfates are soluble except barium sulfate, lead (II)
sulfate and calcium sulfate.
All sodium/potassium/ammonium salts are soluble.
Most carbonates are insoluble except
sodium/potassium/ammonium carbonate.
