All Free Chemistry MCQs with Answers
Every Chemistry question in the bank, across all chapters, each with the correct answer and a written explanation. Free and unlimited, with no account needed.
13,720 questions · page 488 of 686
- A. Size of IIA is greater than IA
- B. LE of IIA is higher than IA
- C. LE of IIA is less than IA
- D. IIA provide more binding electron
Explanation: The melting points of Group IIA elements are considerably higher than those of Group IA elements because Group IIA elements (alkaline…
Correct answer: IIA provide more binding electron- A. Be
- B. Ca
- C. Mg
- D. Sr
Explanation: Among the elements Be, Mg, Ca, and Sr, Magnesium (Mg) has the lowest melting point.
Correct answer: Mg- A. IA
- B. VIIA
- C. VIIIA
- D. VA
Explanation: In the case of alkali metals (Group IA), the melting and boiling points decrease down the group due to the weakening of metallic bonding…
Correct answer: IA- A. Alkali
- B. Amphoteric
- C. Acidic
- D. None of these
Explanation: The elements of group I-A, also known as the alkali metals, react violently with water to produce hydrogen gas and a basic solution of the…
Correct answer: Alkali- A. Decomposition
- B. Acid-base
- C. Combustion
- D. All of these
Explanation: The correct answer is Option B: Acid-base. The reaction between lithium oxide (Li2O) and water (H2) to form lithium hydroxide (LiOH) is…
Correct answer: Acid-base- A. Ba
- B. Li
- C. Ca
- D. All of these
Explanation: Barium is an alkaline earth metal that can form peroxides with Oxygen. Ba+O2500-600°C BaO2 (Barium peroxide).
Correct answer: Ba- A. Mg
- B. Ca
- C. Sr
- D. Ba
Explanation: Barium is a highly reactive metal that requires storage under oil to prevent contact with air.
Correct answer: Ba- A. Na
- B. Rb
- C. K
- D. Cs
Explanation: The correct answer is Cesium (Cs) because as you go down the group of alkali metals, the atomic size increases leading to higher density.
Correct answer: Cs- A. The atomic and ionic radii increase from Be to Ra
- B. Hardness of alkaline earth metals decreases from Be to Ra
- C. Electropositive character decreases from Be to Ra
- D. Melting and boiling points generally decrease from Be to Ra
Explanation: The correct statement is that the atomic and ionic radii increase from Be to Ra.
Correct answer: Electropositive character decreases from Be to Ra- A. Alkaline earth metals are less reactive than alkali metals
- B. Alkaline earth metals except Mg react with dilute acid to give hydrogen gas
- C. Alkaline earth metals are less basic than alkali metals
- D. Alkaline earth metals form ionic bonds with electronegative elements
Explanation: The correct answer is Option B. While most alkaline earth metals react with dilute acids to produce hydrogen gas, magnesium (Mg) also…
Correct answer: Alkaline earth metals except Mg react with dilute acid to give hydrogen gas- A. MgO
- B. SiO2
- C. Al2O3
- D. NO2
Explanation: Magnesium oxide (MgO) is the correct answer as it is an insoluble oxide of an alkaline earth metal, making it unlikely to dissolve in…
Correct answer: MgO- A. Option A
- B. Option B
- C. Option C
- D. Option D
Explanation: The correct answer is Option B. The statement is incorrect because it mistakenly describes the properties of alkaline earth metals (Group…
Correct answer: Option B- A. The elements of both the families are strongly electropositive
- B. All the elements of the two families are highly reactive
- C. None of the elements of the two families occur in the' free state in nature.
- D. The bicarbonates of all the elements of the two families are insoluble in water
Explanation: The correct answer is Option D: The bicarbonates of all the elements of the two families are insoluble in water.
Correct answer: The bicarbonates of all the elements of the two families are insoluble in water- A. Na and K
- B. Li and Na
- C. K and Rb
- D. Rb and Cs
Explanation: Caesium reacts explosively with water, potentially shattering the container, to form caesium hydroxide and hydrogen.
Correct answer: Rb and Cs- A. The alkali metals have one electron in their valence shells whereas the alkaline earth metals have two electrons
- B. The alkaline earth metals are harder and heavier than alkali metals
- C. The carbonates and sulphates of alkali metals except Li2CO3 are soluble in water, whereas those of alkaline earth metals are insoluble
- D. Reactions of alkaline earth metals are more vigorous than those of alkali metals
Explanation: The incorrect statement about alkali and alkaline earth metals is Reactions of alkaline earth metals are more vigorous than those of…
Correct answer: Reactions of alkaline earth metals are more vigorous than those of alkali metals- A. 1 Only
- B. 2 Only
- C. 3 and 4 only
- D. 1,2,3 and 4
Explanation: Lithium exhibits unique properties among alkali metals. It reacts slowly with water, forms stable complex compounds, is harder and lighter…
Correct answer: 1,2,3 and 4- A. It is non-reactive metal
- B. It forms stable layer of oxide
- C. It has non-reactive nature with the acid
- D. It has small size
Explanation: Beryllium becomes passive on reaction with concentrated nitric acid (HNO3) because it forms a thin, protective layer of beryllium oxide…
Correct answer: It forms stable layer of oxide- A. It is as hard as iron.
- B. It is not resistant towards complete oxidation.
- C. Its melting and boiling points are higher than other alkaline earth metal.
- D. It is the only member of alkaline earth metals which reacts with sodium hydroxide to produce hydrogen gas.
Explanation: Beryllium, in particular, is quite resistant towards complete oxidation, even by acids, because of its BeO coating.
Correct answer: It is not resistant towards complete oxidation.- A. Li
- B. Na
- C. K
- D. Cs
Explanation: The element that reacts only with nitrogen and carbon is lithium (Li). It forms specific compounds with these elements, distinguishing it…
Correct answer: Li- A. Be
- B. K
- C. Cl
- D. P
Explanation: The correct answer is beryllium (Be) because it is considered a bridge element with properties that are intermediate between elements in…
Correct answer: Be