Plants can neither grow in too acidic conditions nor grow in too basic conditions. Thus for the proper growth of the plant optimum pH of the soil has to be maintained.

$ N _{1}V _{1} (Na _{2}CO _{3}) = N _{2}V _{2} (A)$
$ N _{1}V _{1} (Na _{2}CO _{3}) = N _{2}V _{2}(B)$
$ N _{1} = 1 , V _{1} = 26ml, V _{2} = 10ml, V _{3} = 40ml$
Normality of A
$ N _{2} = \dfrac{N _{1}V _{1}}{V _{2}} = \dfrac{1 \times 26}{10} = 2.6 N $
Normality of B
$ N _{3}= \dfrac{N _{1}V _{1}}{V _{3}} = \dfrac{1 \times 26}{40} = 0.65 N $
if we mix A & B then
$ N _{1}V _{1} + N _{2} V _{2} = N _{3} (V _{1}+V _{2})$
$ 2.6 V _{1}+0.65V _{2} = 1 \times 1000 $
$ 2.6V _{1}+ V _{2} + 0.65 V _{2} = 1000 ...(1)$
$ V _{1}+V _{2} =1000 ...(2)$
multiply $eq^{n}$ (2) by 0.65 
$ 0.65 V _{1}+0.65V _{2} = 650 ...(3)$
$ V _{2} = 820.6 ml$
$ V _{1} = 1000 - 820.6 = 179.4 ml $
option "a" correct.

$ KMnO _{4}+KNO _{2}$
$ 0.18 N $ 25 ml
V = ? 0.21 N
we know $ N _{1}V _{1}= N _{2}V _{2}$
$ 0.18 \times V _{1} = 0.21 \times 25 $
$ V _{1} = \dfrac{0.21 \times 25}{0.18 }$
$ \boxed{V _{1} = 29.17 ml}$
Answer option C

Indigestion can lead to a feeling of fullness, burping, heartburn (due to gastric acid reflux), etc. Thus an antacid can neutralize the effect of an excess of acid and hence it can be consumed for some relief from heartburn, indigestion, acidity, etc.

Calcium hydroxide called slaked lime is an inorganic compound. It is a colorless crystal and is obtained when calcium oxide is mixed with water. It is used in preparation of dry mixes for painting and white washing.

Caustic soda is sodium hydroxide which is a strong base and so it has high basicity value on $pH$ scale. It is widely used in acid-base titrations to neutralize various strong or weak acids like sulfuric acid.

Acetic acid is a food additive. It is added to adjust pH and acts as a pickling agent for vegetables.

Wasp sting has basic venom. So an acid could be used to treat it.

Soda water is carbonated water. It contains water into which carbon dioxide gas under pressure has been dissolved. It is carbonic acid. The vast majority of carbonated water is sold in drink bottles as soft drinks and beverages.

Vinegar is a liquid consisting about 5-20% of organic acid that is acetic acid $(CH _3COOH)$ and water. It is a mild acid. Vinegar is mainly used as cooking ingredient.

Magnesium hydroxide is also known as milk of magnesia and it is a common component of antacids and laxatives. It interferes with the absorption of folic acid and iron. It carries away much of the body's supply of potassium and neutralizes the stomach acid.

Mouth has salivary amylase enzyme and the process of digestion starts from mouth making the acidic environment which causes the tooth decay so it is neutralized by using toothpaste basic in nature.

Milk of magnesia is $Mg(OH) _2$, it is an alkali.

$Al(OH) _3$ is used in fire extinguisher as a foaming agent.

Sodium hydroxide is used in the manufacture of soaps, paper; in the manufacture of synthetic fibers like rayon and is important constituent in drain cleaners.

Bleaching powder is manufactured from calcium hydroxide.

Calcium hydroxide- $Ca(OH) _2$ is used in the manufacture of bleaching powder. Bleaching powder is used as a disinfectant.

Aluminum hydroxide is an interesting base, because it has a wide number of applications, including its use in antacids. As such, it reacts with and neutralizes stomach acid, and for that reason is found in commercial antacids. It is useful in fire extinguishers as a foaming agent. Aluminum hydroxide is also used in water purification, in dyeing garments, and in the production of certain kinds of glass.

Aqueous potassium hydroxide is employed as the electrolyte in alkaline batteries based on nickel-cadmium, nickel-hydrogen, and manganese dioxide-zinc. Potassium hydroxide is preferred over sodium hydroxide because its solutions are more conductive.

Sodium hydroxide (caustic soda) is used in the manufacture of soap. It is used in petroleum-refining; in making medicines, paper, pulp, etc. It is used in making rayon.

Phosphoric acid is used in dentistry and orthodontics as an etching solution, to clean and roughen the surfaces of teeth where dental appliances or fillings will be placed. Phosphoric acid is also an ingredient in over-the-counter anti-nausea medications that also contain high levels of sugar (glucose and fructose). This acid is also used in many teeth whiteners to eliminate plaque that may be on the teeth before application.

Calcium hydroxide is also known as slaked lime. It is mixed with sand and water to make mortar which is used in the construction of buildings. 

Sodium carbonate is a base which is used as washing soda and for softening hard water.

As it is one of the stronger edible acids, the dominant use of citric acid is as a flavoring and preservative in food and beverages, especially soft drinks. Citric acid is a naturally occurring preservative used in many applications including canning, flavoring, cleaning, and even photography development.

A common base used for cleaning is sodium hydroxide, known commonly as lye or caustic soda. It is not to be taken internally, because it is highly damaging to human tissueparticularly the eyes. Lye appears in drain cleaners, such as Drano, and oven cleaners, such as Easy-Off, which make use of its ability to convert fats to water-soluble soap.

Baking soda, known by chemists both as sodium bicarbonate and sodium hydrogen carbonate, is another example of a base with multiple purposes. The reaction of the acid and the baking soda produces carbon dioxide, which causes dough and batters to rise.

Lakes and oceans can become acidic due to acid rain. This increases the acidity of such bodies and affects the aquatic life. To neutralize this acidic behavior of lakes and oceans, calcium carbonate $(CaCO _3)$ is used.

The pH in our mouth is 5.5 which is slightly acidic. If the pH in our mouth decreases it results in tooth decay due to formation of certain acids. Toothpaste is basic in nature which neutralizes the acid and protects from tooth decay.

Treatment of gastric patients, treatment of acidic effluents from factory wastes and treatment of acid/base salts, are examples of neutralization in everyday life. Hence, D

To improve the quality of a basic soil, an acid should be added. Slaked lime ($ Ca{ (OH) } _{ 2 } $) and quick lime ($ Ca{ O }$) are basic in nature. Urea is neutral. Hence, organic matter is the answer.

The venom of ant sting is acidic in nature, which is neutralised by the application of alkali like sodium bicarbonate. Indigestion happens due to over production of hydrochloric acid in stomach, which is neutralised by an antacid which is alkali in nature. These are examples of neutralisation in everyday life.

Loam soil is considered ideal for gardening and agricultural uses because it retains nutrients well and retains water while still allowing excess water to drain away.

The venom of honey bee and ant bites are acidic in nature. So, it's effects can be neutralised by bicarbonate of soda such a baking soda or an alkali (basic in nature). 

The venom of a honey bee is acidic in nature. 

Toothpaste is slightly basic is nature (pH ~ 8). The acid produced on the tooth enamel (commonly known as acid erosion) is neutralised by the toothpaste, cleaning your teeth. Hence, usage of toothpaste is the example of a neutralisation reaction.

1. Formic acid is produced by ants and acetic acid is used as anti-wasp agents.
   2. In alkali batteries a base is used as an electrolyte which gives hydroxyl ions in solution.
   3. Manufacturing of soap requires an alkali like $NaOH$ and long chain of fatty acids like sodium stearate to form an ester or sodium acetate salt.

Ammonia solution is good for removing stains and tarnish and can also repel moths and reduce paint odours. As ammonia reacts with the water, it is dissolved in to produce ammonium ions and hydroxide ions.

Milk of magnesia (also known as magnesium hydroxide; $ { Mg }{ (OH) } _{ 2 } $) is basic in nature and one of the most important ingredients of an antacid. 

The venom ant bites are acidic in nature. So, it's effects can be neutralised by bicarbonate of soda such a baking soda or an alkali (basic in nature).