Chemistry · Science General

Common Chemical Compounds and Reactions

1,204 Questions

Common chemical compounds and reactions questions test your knowledge of everyday chemicals, their formulas, and their interactions. Topics include properties of acids and bases, hard water chemistry, and compounds like baking soda and plaster of paris. This section is essential for general science preparation.

Acids and basesPlaster of parisHard water chemistryCommon chemical formulasEveryday chemical reactions

Common Chemical Compounds and Reactions Questions

Multiple choice bio-chemistry immunity and blood groups blood group blood groups and compatibility advance blood groups and transfusion compatibility of blood groups

Which of the following chemicals can be used as anticoagulant?

  1. Sodium chloride

  2. Sodium citrate

  3. Sodium nitrate

  4. Ammonium chloride.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Sodium citrate is a common anticoagulant used in blood collection because it chelates calcium ions, which are necessary for the blood clotting cascade.

Multiple choice bio-chemistry immunity and blood groups blood group blood groups and compatibility advance blood groups and transfusion compatibility of blood groups

Which one is the common anticoagulant used for preserving blood?

  1. Sodium hydroxide

  2. Sodium chloride

  3. Sodium oxalate

  4. Sodium bicarbonate.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Sodium oxalate and sodium citrate are common anticoagulants used in blood collection tubes because they bind calcium ions, which are essential for the blood clotting cascade.

Multiple choice biology windows of knowledge human tongue organ of taste tongue : the organ of taste

The taste of salt is mediated by

  1. Na+

  2. Ca+

  3. K+

  4. None of the above
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
The taste of salts is mediated by Na$^+$ ions which do not interact with a membrane receptor but diffuse through a Na$^+$ channel located in the microvilli and apical membrane. Anions such as Cl$^-$ contribute to the salty taste, but anions are transported into these cells by a paracellular route. The influx of these ions of salt evokes a depolarization in the apical membrane.
So, the correct answer is option A.
Multiple choice biology movement in and out of the cell transport of molecules osmosis and plasmolysis plant water relation

Which one of the following is the correct statement for an active sodium-potassium ATPase ?

  1. It pumps out 3 Na-ions and pumps in 2 K-ions

  2. It pumps out 3 Na-ions and pumps in 3 K-ions

  3. It pumps out 3 Ca-ions and pumps in 2 K-ions

  4. It pumps out 3 Na-ions and pumps in 2 Ca-ions
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Sodium-potassium pump is important to produce action potential by nerve cells. As it transport of three Na+ to the outside of the cell and the transport of two K+ ions to the inside. This changes the membrane potential on the inside, making the inside of the cell more negative or hyperpolarized, which leads to forward movement of electric impulse

So, the correct answer is 'It pumps out 3 Na$^+$and pumps in 2 K$^+$ '

Multiple choice evs - i constituents of food minerals in our diets types of nutrients nutrients and deficiency

Various types of crystals of calcium carbonate or oxalate are reported in certain families which can also be regarded as aid to taxonomy. Crystals of gypsum are present either singly or in clusters in

  1. Tomarix dioica

  2. Ficus benghalensis

  3. Momordica charantia

  4. Nymphaea sp.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Crystals of calcium oxalate, starch grains, stone cells with lignified walls, brown tannin cells, and crystals of gypsum are present in the cells of Ficus benghalensis, they belong to family Moraceae. The presence of different crystals is the characteristic feature that distinguishes families from each other.

So, the correct option is 'Ficus benghalensis'.

Multiple choice evs - i constituents of food minerals in our diets types of nutrients nutrients and deficiency

Among the below given minerals, Potassium Chloride is extracted from
a) Sylvite
b) Carnallite
c) Potash

  1. Only a

  2. Only a and b

  3. Only b and c

  4. All a,b and c
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Potassium Chloride can be extracted from-

$a.$ Sylvite (Potassium Chloride in natural mineral form)
$b.$ Carnallite $(KCl\cdot MgCl _2\cdot 6H _2O)$
$c.$ Potash (rich in potassium chloride)

Multiple choice chemistry chemical changes electrochemical reactions electrolysis and its applications electrolytic cells and electrolysis

In Down's process for the manufacture of sodium, $CaCl _2$ is added to:

  1. decrease the melting point

  2. increase the melting point

  3. decrease the interionic interactions

  4. increase the interionic interactions
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

$CaCl _2$ is added to lower the melting point from 1080 K (melting point of NaCl) to 850 K. This is due to following reasons.
a. At such high temperature, it is very difficult to maintain Na in the molten state during electrolysis.
b. Moreover, Na is voltile at this temperature and a part of it would vapourize.
c. Molten Na, gets dispersed in molten NaCl to form metallic fog at high temperature.
d. Both Na and $Cl _2$ produced in the electrolysis have a corrosive action on the vessel used.
The over all reactions nare as follows :
At cathode : $Na^{\oplus} + e^{-} \rightarrow Na$
At anode : $Cl^{\ominus} \rightarrow \displaystyle \frac{1}{2} Cl _2 + e^{-}$

Multiple choice chemistry chemical changes electrochemical reactions electrolysis and its applications electrolytic cells and electrolysis

Which of the following aqueous solutions remain alkaline after electrolysis ?

  1. $CH _{3}COONa$
  2. $KNO _{3}$
  3. $NaCl$
  4. $LiF$
Reveal answer Fill a bubble to check yourself
A,C Correct answer
Explanation

a. Reduction potential of $H _{2}O\, >$ Reduction potential of $Na^{\oplus}$
Hence, 
Cathode : $2H _{2}O\, +\, 2e^{-}\, \rightarrow\, 2 \overset{\ominus}{O}H\, +\,\begin{matrix} H _{2}\ (solution\, is\, basic)\end{matrix}$

Anode : $CH _{3}\, COO^{\ominus}\, \overset{Kolbe's\, electrolysis}{\rightarrow}\, C _{2}H _{6}\, (Ethane)\, +\, 2CO _{2}$

b. $K^{\oplus}$ does not undergo reduction but reduction of $H _{2}O$ occurs to give $\overset{\ominus}{O}\, H$ ion and $H _{2}(g)$.
Similarly, $NO^{\ominus} _{3}$ ion does not undergo oxidation but oxidation of $H _{2}O$ occurs to give $H^{\oplus}$ ions and $O _{2}(g)$. 
$H^{\oplus}$ and $\overset {\ominus}{O}H$ ions get neutralised and pH = 7 (neutral solution).
c. $Na^{\oplus}$ ions do not undergo reduction but reduction of $H _{2}O$ occurs to give $\overset{\ominus}{O}H$ ions and $H _{2}(g)$. (Hence, solution is basic). $Cl^{\ominus}$ undergoes oxidation to give $Cl _{2}(g)$. 
d. Same explanation as in (b).

Hence, options A and C are correct.

Multiple choice chemistry the s-block elements (alkali and alkaline earth metals) some important compounds of calcium some important compounds of magnesium and calcium compounds of s block elements

The reaction of water with slaked lime is studied by ________ .

  1. putting slaked lime into water taken in a test tube

  2. putting a lot of water into slaked lime.

  3. sprinkling a little water on slaked lime.

  4. none of the above method.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The reaction of water with calcium oxide (quicklime) to form slaked lime is highly exothermic. To study it safely, one typically adds small amounts of water to the lime or vice-versa under controlled conditions, but the standard laboratory demonstration involves adding water to the solid.

Multiple choice chemistry the s-block elements (alkali and alkaline earth metals) some important compounds of calcium some important compounds of magnesium and calcium compounds of s block elements

The function of quick lime mixture is to:

  1. Absorb moisture present in soda lime

  2. increase the efficiency of soda lime

  3. Increase the pH of soda lime

  4. Take part in reaction with NaOH
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

$CaO$ is a compound that absorbs moisture easily and rapidly.

So it is used in some lime. It also adsorbs $CO _2$
Hence option A is the correct answer.

Multiple choice chemistry the s-block elements (alkali and alkaline earth metals) some important compounds of calcium some important compounds of magnesium and calcium compounds of s block elements

Setting of plaster of paris involves:

  1. oxidation with atmospheric oxygen
  2. combination with atmospheric $CO _{2}$

  3. dehydration

  4. hydration to yield another hydrate
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

On hydration of Plaster of Paris, converts into Gypsum.
$\underset {\text {Plaster of Paris}}{CaSO _{4} \cdot \dfrac {1}{2} H _{2}O} + \dfrac {3}{2} H _{2}O\rightarrow \underset {Gypsum}{CaSO _{4}\cdot 2H _{2}O}$

Multiple choice chemistry the s-block elements (alkali and alkaline earth metals) some important compounds of calcium some important compounds of magnesium and calcium compounds of s block elements

Identify which contributes for strengthening of lime mortar structures and contributes for weakening of RCC structures the factor(s).

  1. Usage of water containing dissolved salts

  2. Addition of lime
  3. Absorption of $CO _2$ from atmospheric air

  4. Both B and C
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Absorption of $CO _{2}$ from atmospheric air contributes for strengthening for lime mortar structure as when atmospheric $CO _{2}$ combines with hydrated lime, limestone is formed which is a solid.

RCC structures are plain cement concrete reinforced with steel bars. Generally, the pH of new concrete is 12-13 which surrounds embedded reinforcement with the passivating layer of highly alkaline cement protecting reinforcement against corrosion. When atmospheric $CO _{2}$ comes in contact with the RCC structure it gets corroded and production of $CaCO _{3}$ occurs due to which alkalinity of the concrete decreases and the steel reinforcement is then susceptible to corrosion. This is how RCC structure gets weaken in the presence of atmospheric $CO _{2}$