Skip to main content

What is Photosynthesis ?

By Sachin Joshi
Post a Comment

Acid-base in water / Dilution / pH scale( universal indicator )

Image
By Sachin Joshi



 I) What happens to an Acid  in a Water Solution ?


->  The hydrogen ion produced in the presence of water in HCl.
- >The separation of H+ ion from HCl molecules cannot occur in the absence of water.
  HCl + H2O --------> H3O+  + Cl-
- >Hydrogen ions cannot exist alone but exist after combines water molecules hence H+ (aq) or hydronium ion (H3O+).
  H+ + H2O --------> H3O+

II) What happens to an Base in a Water Solution ?

- >Bases generate hydroxide (OH-) ions in water. 
Bases which soluble in water are called alkalis.
  Examples:- 
 a) NaOH(s) + H2O(l) --------> Na+(aq) + OH-(aq)
 b) KOH(s) + H2O (l) ----------> K+ (aq) + OH- (aq)
 c)  Mg(OH)2 (s) + H2O (l) ----------> Mg2+(aq) +2OH- (aq)

III) Process of mixing of Acid or a Base with Water.

- >The process of dissolving an acid or a base in water is a exothermic process.
 - >We must take care when doing this process.
Like mixing of concentrated nitric acid or sulphuric acid with water. During this process the acid must added slowly to water with constant stirring.  
If water is added to concentrated acid, the heat generated cause the mixture to splesh out and cause burn. The glass container may also break due to excessive heating.  The warning sign ( shown below) on the can of concentrated Acids and on concentrated Bases are labelled.


- > Mixing an acid or base with water results in the decrease in the concentration of ions (H3O+/OH-) per unit volume and the process is called dilution and the acid or base is said to be diluted.

IV) How strong are  acid or base solution ?

- > Acid - Base indicators are used to distinguish between an acid or base(like Litmus paper, Methylorange, Phenolphthalein etc).
- > We can quantify and measure the strength of acid or base by measuring the ions present in a solution using universal indicator.

•What is universal indicator ?
-> Universal indicator is the mixture of several indicators which shows different colour at different concentrations of hydrogen ions in a solution.

•What is pH scale ?
- > A scale for measuring hydrogen ion concentration in a solution is called as pH scale. Where p stands for 'potenz' in German, meaning power.
- > On pH scale we measure pH generally from 0 ( very acidic) to 14 ( very alkaline). 
- >It is a simply as number on pH scale which indicates the acidic or basic nature of a solution. Higher the hydronium ion concentration , lower is the pH value.
- > Reading 7 on pH scale indicates neutral Solution.
- > Value less then 7 on pH scale represents an acidic solution and increase in H+ ion concentration.
-  >Reading more then 7 to 14 on pH scale represents an basic solution which also represents increase in OH- ion concentration in the solution ( alkali)

•Strong acids:-
       - > The acids that give rise more H+ ions are said to be strong acids.
Example:- Hydrochloric acid (HCl), Nitric acid (HNO3), Sulphuric acid (H2SO4) etc 
•Weak acid:-
      - >  The acids that give rise to less H+ ions are said to be weak acids.
Example:- Formic acid (HCOOH), Acetic acid (CH3COOH), Benzoic acid ( C6H5COOH) etc.

•Strong base:-
       - >  The bases that give rise to more OH- ions are said to be strong Base.
Example:- Sodium hydroxide (NaOH), Potassium hydroxide (KOH), Calcium hydroxide(CaOH) etc.
 •Weak base:- 
       - >  The bases that give rise to less OH- ions are said to be weak Base.
Example:- Ammonia (NH3), Trimethylamine (N(CH3)3), Pyridine (C5H5N) etc.
 

#You tube chennel link:- https://youtu.be/LoIbygPUZPA

 

 





Labels: YouTube , Telegram
Location: India , world , India

Comments

Post a Comment

If you have any doughts please let me know

Popular posts from this blog

Chemical reaction and equation

By Sachin Joshi
                   CHAPTER NUMBER I ---------------------------------------------------------------------------- CHEMICAL REACTION AND EQUATION  * Chemical reaction : -               A chemical reaction is a process in which one or more substances are converted into one or more different substances. During a chemical reaction, the bonds between atoms in the reactants are broken and new bonds are formed to create the products.  Chemical reactions can be represented by chemical equations, which show the reactants on the left-hand side of the equation and the products on the right-hand side. For example, the chemical equation for the reaction between hydrogen gas (H2) and oxygen gas (O2) to form water (H2O) is:  2H2 + O2 → 2H2O  This equation shows that two molecules of hydrogen gas and one molecule of oxygen gas react to form two molecules of water.  * Chemical reactions can ...
Post a Comment
Read more

What is Photosynthesis ?

By Sachin Joshi
                        WHAT IS PHOTOSYNTHESIS? Photosynthesis is the process by which plants, algae, and some bacteria convert light energy into chemical energy in the form of glucose and other organic compounds. It is a complex biochemical process that occurs in the chloroplasts of plant cells and involves the absorption of light by pigments such as chlorophyll. The overall equation for photosynthesis is: 6CO2 + 6H2O + light energy → C6H12O6 + 6O2 In this equation, carbon dioxide (CO2) and water (H2O) are converted into glucose (C6H12O6) and oxygen (O2) through a series of reactions that involve the transfer of electrons and the formation of ATP, a molecule that stores energy. Photosynthesis occurs in two main stages: the light-dependent reactions and the light-independent reactions. In the light-dependent reactions, light energy is absorbed by chlorophyll and other pigments, and used to generate ATP and NADPH, which are ener...
Post a Comment
Read more

Metals and Non- Metals / part III / reactivity Series of metals and Extraction of metals from their ores

By Sachin Joshi
*Reactivity Series :-    Reactivity series of metals The Arrangement of elements according to their reactivity is called reactivity series. * Reaction Of Metals with water. Metal react with water to form metal hydroxide and hydrogen gas is released Metal +water ------->metal hydroxide +hydrogen gas Na (s)  + cold H2O (l) ------------>NaOH (aq)+H2(g) K (s) + cold H2O (l) ---------> KOH (aq) + H2 (g) Note:-  Some Metals react with cold water: Sodium and Potassium are the metals which reacts with cold water. * Metals reacts with hot water Some Metals react with hot water: Calcium and Magnesium are the metals which reacts with hot water. Ca (s) + hot H2O (l)  --------> Ca(OH)2 (aq) Mg(s) + hot H20 (l) ----------> Mg(OH)2 (aq) Note:-  Some react with steam:Metals like Iron, Zinc and Aluminium react with steam *when iron reacts with steam : Fe (s)+steam H2O(l)--------->Fe3O4(s) + H2 (g) Some elements don't reacts:- Elements bel...
Post a Comment
Read more