anybody have target 10 standard science 2 notes of second lesson then plzz send me photos plzzz
Answers
Answer:
Acids, Bases and Salts
Explanation:
Acids - Acids are compounds which give hydrogen ion in water solution. For example, Hydrochloric acid (HCl), Sulphuric acid(H2SO4), Nitric acid(HNO3).
Bases - Bases are compounds which give hydroxide ion in water solution. For example, Sodium hydroxide(NaOH), Potassium hydroxide(KOH), Calcium hydroxide( Ca(OH)2).
Salts - Salts are compounds obtained by replacement of H from acid by a metal. For example, Sodium chloride (NaCl), Copper sulphate (CuSO4), Potassium nitrate (KNO3).
Strong and Weak -
Strong acids ionize fully in water to produce large number of H+ ions. For example, Hydrochloric acid (HCl), Sulphuric acid(H2SO4), Nitric acid(HNO3), hydrobromic acid(HBr).
Weak acids ionize partially in water to produce small number of H+ ions. For example, carbonic acid(H2CO3), phosphoric acid(H3PO4), sulphurous acid(H2SO3), acetic acid(CH3COOH).
Strong bases ionize fully in water to produce large number of OH- ions. For example, sodium hydroxide (NaOH), potassium hydroxide (KOH), lithium hydroxide (LiOH), calcium hydroxide (Ca(OH)2).
Weak bases ionize partially in water to produce small number of OH- ions. For example magnesium hydroxide (Mg(OH)2), ammonium hydroxide (NH4OH).
Concentrated and Dilute -
A concentrated solution is a solution in which large amount of solute is dissolved in less amount of water (solvent).
A dilute solution is a solution in which small amount of solute is dissolved in large amount of water (solvent).
For example, concentrated hydrochloric acid have more amount of HCl and less amount of water. On the other side, dilute hydrochloric acid have less amount of HCl and more amount of water.
Diluting Acids and Bases -
If concentrated acid (or base) is mixed with water, concentration of hydronium ions () decreases. So the acid or base becomes dilute.
The phenomena of changing concentrated acid / base into dilute acid / base (respectively) is an exothermic reaction.
Always add concentrated acid/base to water; not water to concentrated acid/base.
When concentrated acid is added to water, heat is released gradually. This heat is absorbed by large amount of water to increase its temperature.
When water is added to concentrated acid, heat is released suddenly. This heat vaporizes small amount of water to steam. This steam is splits out with drops of concentrated acid which can damage our body. So always add concentrated acid to water, not water to concentrated acid.
Same is true with base also.
Presence and Taste -
Acids -
The word ‘Acid’ came from Latin word ‘Acidus or Acere’ which means sour. Sour taste is the most common characteristic of acid. There are many substances which contain acid and hence taste sour, such as curd, grapes, tamarind, lemon, tomato etc.
Types of Acids -
Acids can be divided into two types on the basis of their occurrence -
Natural acids
Mineral acids.
Natural Acid - Acids which are obtained from natural sources (plants and animals) are called natural acid or organic acid.
Commonly found organic acids Their natural sources
Citric acid
Orange, lemon
Tartaric acid
Tamarinds, grapes
Lactic acid
Curd/ sour milk
Oxalic acid
Tomatoes
Acetic acid
Ketchup, vinegar (sirka)
Formic acid (Methanoic acid)
Ant sting, nettle leaf sting
Mineral Acids - Acids that prepare from mineral are known as mineral acids/ inorganic acids/man-made acids or synthetic acid, such as hydrochloric acid (HCl), sulphuric acid (H2SO4) , nitric acid (HNO3), etc.
Note:
Organic acids are always weak but minerals acids can be strong as well as weak.
We can take dilute weak acids (like organic acid) in our body. But strong acids (like strong mineral acids) are very harmful for us.
Bases -
Bases are bitter in taste and feels soapy on touch. There are many substances which contain bases such as soap, detergents, white wash etc.
Some common bases Presence
Sodium hydroxide (NaOH)
Soap, detergents, caustic soda
potassium hydroxide(KOH)
Caustic potash
sodium carbonate(Na2CO3)
Washing soda
Calcium hydroxide(Ca(OH)2)
White wash
Conduction of Electricity in Acids/Bases -
Take solution of hydrochloric acid (HCl).
Fix two nails on a cork, and place the cork in a beaker.
Connect the nails to the two terminals of a 6 volt battery through a bulb and a switch.
Now pour some dilute HCl in the beaker and switch on the current.
What do you observe?
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Bulb will start glowing.
It indicates that there is flow of electricity in HCl solutions.
When we pour some dilute HCl in beaker, it gets ionized and produces hydrogen ions(H+) and chloride ions(Cl-).
(Chloride ion)
(Hydrogen ion)
Hydrogen ions react with water and make hydronium ions.
(Hydronium ion)
These chloride and hydronium ions can move in solution to conduct electricity.
You can repeat the same activity with other acids and bases.
Acid and base solution can conduct electricity due to formation of mobile ions. Therefore, acid and base solutions are called electrolytes.