Free s-Block and p-Block Elements MCQs with Answers
1,359 s-Block and p-Block Elements MCQs from Chemistry, each with the correct answer and a written explanation of why it is correct. Free and unlimited, with no account needed.
The s and p blocks are studied through their valence-shell configurations, periodic trends and characteristic chemical properties. Work covers the reactions of Group I and Group II elements, the behaviour of Group IV elements, and how atomic size, ionization energy, electronegativity and metallic character change across periods and down groups.
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1,359 questions · page 10 of 68
- A. NaOH
- B. KOH
- C. NaCl
- D. NaBH4
Explanation: Potash refers to potassium compounds, and caustic potash is potassium hydroxide, KOH. Sodium hydroxide, NaOH, is called caustic soda.
Correct answer: KOH- A. being s-block elements
- B. inert gas configurations
- C. ns1 electronic configuration
- D. being metals
Explanation: An alkali metal has the outer configuration ns1, so removal of its first electron produces a stable noble-gas configuration.
Correct answer: inert gas configurations- A. Lithium
- B. Sodium
- C. Potassium
- D. Rubidium
Explanation: Lithium reacts with oxygen mainly to form the normal oxide, Li2O. The larger alkali metals form peroxides or superoxides because their…
Correct answer: Lithium- A. Water
- B. HCI
- C. Na+
- D. NaCl
Explanation: At the cathode of a diaphragm cell, water is reduced more readily than sodium ions: 2H2O + 2e− → H2 + 2OH−.
Correct answer: Water- A. Na K
- B. Mg Ca
- C. Li Na
- D. Li Ca
Explanation: Lithium nitrate decomposes on heating to lithium oxide, nitrogen dioxide and oxygen: 4LiNO3 → 2Li2O + 4NO2 + O2.
Correct answer: Li Na- A. Base
- B. Basic salt
- C. Ashes
- D. Spirit
Explanation: The term alkali comes from an Arabic word referring to the ashes of plants, from which alkaline substances such as carbonates were…
Correct answer: Ashes- A. LiOH
- B. NaOH
- C. KOH
- D. CsOH
Explanation: LiOH has the greatest covalent character among the alkali-metal hydroxides because the small Li+ ion strongly polarizes OH−.
Correct answer: LiOH- A. sodium
- B. hydrogen
- C. chlorine
- D. oxygen
Explanation: In dilute aqueous sodium chloride, water is preferentially oxidized at the anode: 2H2O → O2 + 4H+ + 4e−.
Correct answer: oxygen- A. It corrodes the organic tissues
- B. It is used in soda water
- C. It reacts with chlorine gas
- D. It reacts with fats to form soap
Explanation: Sodium hydroxide is called caustic soda because it is strongly corrosive and can chemically burn organic tissues.
Correct answer: It corrodes the organic tissues- A. Hydroxide ions to reach anode
- B. Chlorine gas to mix
- C. Cathode to decay
- D. All of the above
Explanation: In a diaphragm cell, the anode compartment is kept at a slightly higher liquid level so brine flows towards the cathode compartment.
Correct answer: Hydroxide ions to reach anode- A. Water
- B. NaCl
- C. Aqueous sodium hydroxide
- D. H2SO4
Explanation: Heating ammonium chloride with aqueous sodium hydroxide gives ammonia, water and sodium chloride: NH4Cl + NaOH → NH3 + H2O + NaCl.
Correct answer: Aqueous sodium hydroxide- A. Sodium carbonate
- B. Sodium bicarbonate
- C. Sodium metal
- D. Sodium hydroxide
Explanation: The Downs cell electrolyses molten sodium chloride to produce sodium metal at the cathode and chlorine gas at the anode.
Correct answer: Sodium metal- A. Low electronegativity
- B. Low electropositivity
- C. Low charge density
- D. Not known yet
Explanation: Lithium ion has a small size and high charge density, so it strongly polarizes the carbonate ion and makes Li2CO3 less stable on heating…
Correct answer: Low electropositivity- A. small size
- B. high charge density
- C. less electropositivity
- D. all of the above
Explanation: Lithium differs from the other alkali metals because its atom and ion are unusually small, giving Li+ a high charge density; it is also…
Correct answer: all of the above- A. NaNO3
- B. CaCO3
- C. Ba (NO3)2
- D. NH4Cl
Explanation: Chile saltpetre is the mineral name for sodium nitrate, NaNO3, a naturally occurring nitrate deposit from Chile.
Correct answer: NaNO3- A. Their oxides are basic
- B. Their oxide and hydroxides are water soluble
- C. Both A & B
- D. They are found in earth
Explanation: Group 1 metals are called alkali metals because their oxides and hydroxides produce soluble alkaline solutions in water.
Correct answer: Both A & B- A. Hard water
- B. Heavy water
- C. Soft water
- D. Water gas
Explanation: Deuterium is the heavy isotope of hydrogen, so its oxide is D2O, commonly called heavy water.
Correct answer: Heavy water- A. form starch sugar and fibrous material
- B. ripen the seeds and fruits
- C. increase the resistance against disease
- D. all the above statements are correct
Explanation: Potassium activates enzymes and improves several plant processes, including starch and sugar formation, seed and fruit development, and…
Correct answer: all the above statements are correct- A. Na K
- B. Mg Ca
- C. Li Na
- D. Li Ca
Explanation: Lithium nitrate decomposes to lithium oxide, whereas sodium nitrate decomposes to sodium nitrite: 4LiNO3 -> 2Li2O + 4NO2 + O2 and 2NaNO3…
Correct answer: Li Na- A. Chlorine
- B. Silver nitrate
- C. Copper Sulfate
- D. Nitric acid
Explanation: Copper sulfate is mixed with milk of lime to form Bordeaux mixture, which is used as a fungicide against fungi and moulds.
Correct answer: Copper Sulfate