:
Any one source
Tamarind is a naturalsource of tartaric acid.
Various other sources of tartaric acid are grapes, unripe mangoes, etc.

Answer: Option B. -> base
:
B
Sodium hydroxide, caustic soda - NaOH,is a base because it can render hydroxide ions in aqueous solution. It turns red litmus solution blue.

Answer: Option A. -> fertilisers
:
A
The chemical formula of ammonium hydroxide is ${\text{NH}}_4\text{OH}$. It gives ${\text{OH}}^{-}$ ions when added in water. Hence it a base. It is mainly used in the manufacturing of fertilisers.

Answer: Option C. -> Both statements are true
:
C
The rain becomes acidic because carbon dioxide, sulphur dioxide and nitrogen dioxide (which are released into the air as pollutants) dissolve in rain drops to form carbonic acid, sulphuric acid and nitric acid respectively. Acid rain can cause damage to buildings, historical monuments because they react with the upper layers of the buildings or monuments and corrodes them, they also damage plants and animals by damaging the upper layer of their skin.

Answer: Option B. -> False
:
B
Nitric acid turns blue litmus red as it is acidic in nature. Acids turn blue litmussolution to red colorbut do not have any effect on red litmussolution.

Answer: Option B. -> False
:
B
Phenolphthalein is an acid-base indicator which is colourless in acid solution but turns pink to red as the solution becomes alkaline.

Answer: Option A. -> Bases are sour in taste
:
A and D

Bases tend to taste bitter and feel slippery. Bases turn red litmus blue.​

Answer: Option B. -> False
:
B

The sting of an ant contains formic acid which causes irritation on the skin. Calamine solution contains zinc carbonate which is a base. Calamine solution neutralizes the acid effect of the ant bite when applied on the skin.​​

Answer: Option D. -> Vinegar
:
D

Baking soda, Caustic soda and toothpaste are basic in nature.
Vinegar is the only acid in the given list.

Answer: Option B. -> Baking soda
:
B
The common name of sodium bicarbonate $\left({\text{NaHCO}}_3\right)$ is baking soda. It is added to bakery products like bread and cakes.