Answer: Option A. -> 1M hydrochloric acid
:
A
Strong acids release ${\text{H}}^{+}$ions more easily than weaker ones. Hydrochloric acid $(\text{HCl}$) is a strong acid, whereas, acetic acid $\left({\text{CH}}_3\text{COOH}\right)$, citric acid $\left({\text{C}}_6{\text{H}}_8{\text{O}}_7\right)$ and propanoic acid $\left({\text{CH}}_3{\text{CH}}_2\text{COOH}\right)$ areweak acids.
So, 1M hydrochloric acid will have a higher concentration of${\text{H}}^{+}$ions than acetic acid and propanoic acid.

Answer: Option B. -> Alkalis
:
B
A base is any substance that neutralises an acid. It may or may not be soluble in water. Those bases that are soluble in water are knownas alkalis. Thus, an alkali is a water soluble base. For eg., NaOH, KOH etc.

Answer: Option B. -> Universal Indicator
:
B
The most commonly used indicator in the laboratory is 'Universal Indicator'.Auniversal indicatoris apH indicatorcomposed of asolutionof several compounds that exhibits several smoothcolourchanges over apHvalue range from 1 to 14 to indicate theacidityor alkalinity of solutions.

:
An acid reacts with a base to form salt and water.
For example, when hydrochloric acid reacts with sodium hydroxide solution, sodium chloride and water are formed. This is called as neutralisation reaction.
NaOH + HCl $\to$NaCl + $H_{2}O$

Answer: Option B. -> Olfactory indicator
:
B
An olfactory indicator is a substance of which smell varies depending on whether it is mixed with an acidic or a basic solution.Vanilla, clove and onion are olfactory indicators.
Gustatoryindicator are substances that can change its taste depending on their reaction with acid or base. Tongue is an example of gustatory indicator.

Answer: Option A. -> less than seven
:
A
Gastric juices that are released in the stomach are acidic in nature. Thus, their pHis less than seven. When they are released in excess quantity, we take mild bases like baking soda to neutralise its effect.

Answer: Option A. -> NH4Cl
:
A
Salts of a strong acid and a strong base are neutral with pH value of 7. On the other hand, salts of a strong acid and weak base are acidic with pH value less than 7 and those of a strong base and weak acid are basic in nature, with pH value more than 7.
$\bullet$$N{H}_{4}Cl$ is a salt of weak base$\left(N{H}_{4}OH\right)$ and strong acid $\left(HCl\right)$.Hence, it is a acidic salt.
$\bullet$$C{H}_{3}COONa$ is salt of weak acid$\left(C{H}_{3}COOH\right)$ and strong base $\left(NaOH\right)$. Hence, it is a basic salt.
$\bullet$$KCl$ is salt of strong acid$\left(HCl\right)$ and strong base$\left(KOH\right)$. Hence, it is a neutral salt.
$\bullet$$NaCl$ is salt of strong acid$\left(HCl\right)$ and strong base$\left(NaOH\right)$. Hence, it is a neutral salt.

Answer: Option A. -> Formic acid
:
A
Ant sting contains formic acid. The chemical formula for formic acid is HCOOH.

Answer: Option B. -> False
:
B
This statement is false.On heating sodium hydrogen carbonate it decomposes to form sodium carbonate, water and carbon dioxide.
${2NaHCO}_3$ → ${Na}_2{CO}_3$ + ${CO}_2$ + $H_{2}O$

Answer: Option A. -> True
:
A
For any substance to conduct electricity, there must be the availability of mobile charge carriers. These charge carriers can be:
$\bullet$ free electrons that can flow within the substance.
$\bullet$ ions that can flow in the solution.
An acid when added in water dissociates into its corresponding ions. For example, hydrochloric acid (HCl) when added to water, dissociates into ${\text{H}}^{+}$ and ${\text{Cl}}^{-}$ ions. These ions present in the solution conduct electricity.