All Free Chemistry MCQs with Answers

• A. Lithium
• B. Radium
• C. Boron
• D. Uranium

Explanation: The correct answer is Radium. Marie and Pierre Curie successfully isolated radium from pitchblende in 1902, contributing greatly to the…

• A. Magnesium and Sodium
• B. Magnesium and Copper
• C. Magnesium and Barium
• D. Magnesium and Potassium

Explanation: Refer to the image below. As we can see in the periodic table, Magnesium and Barium are the only two metals from the options which are in…

• A. hydride ion
• B. hydronium ion
• C. proton
• D. hydroxyl ion

Explanation: The Ionization of a hydrogen atom refers to the process of removing an electron from a hydrogen atom, resulting in the formation of a…

• A. K2CO3
• B. Li2CO3
• C. Na2CO3
• D. Rb2CO3

Explanation: All except Lithium are soluble in water and stable to heat.

• A. Orange red
• B. Golden yellow
• C. Red
• D. Pink

Explanation: The flame of Ca is orange-red so, A is the correct option. A yellow flame is of Sodium (Na), Red flame is of Lithium (Li), and Pink flame…

• A. BaCO3
• B. MgCO3
• C. CaCO3
• D. SrCO3

Explanation: 'Barium carbonate' is thermally the most stable. As we move down the group, the charge density of the cation decreases due to increasing…

• A. Ba
• B. Be
• C. Mg
• D. Ca

Explanation: The alkaline earth metals burn in oxygen to produce oxides or in the case of barium, peroxide.

• A. alkaline earth metals
• B. alkali metals
• C. chalcogens
• D. noble metals

Explanation: Group 1 elements include the alkali metals, Li, Na, K, Rb, Cs, Fr. The alkali metals are all soft, shiny and metallic when cut.

• A. Bromine
• B. Fluorine
• C. Chlorine
• D. Iodine

Explanation: One of the easiest and cost effective way to clean water is to add some amount of chlorine into it.

• A. Lanthanides
• B. Actinides
• C. Alkali metals
• D. Noble gases

Explanation: The reactivity of lanthanides is generally lower than that of the corresponding alkali and alkaline earth metals.

• A. Na
• B. K
• C. Cs
• D. Mg

Explanation: Alkali metals are Group 1 metals and Mg is in Group 2 and the rest of the three options are elements from Group 1.

• A. Cs
• B. Na
• C. Li
• D. K

Explanation: Li more closely resembles the metals of group 2 than the metals of its own group (1).

• A. HF
• B. NaCl
• C. HCl
• D. CsF

Explanation: CsF has the highest ionic character because Cs is the most electropositive element and Fluorine is the most electronegative element.

• A. Number of shells
• B. Number of electrons
• C. Electronic configuration
• D. Number of protons

Explanation: The atomic number of Na is 11, so it has 11 electrons and 11 protons . But Na+ has lost 1 electron, so Na+ has 10 electrons and 11…

• A. Ⅰ-B
• B. Ⅱ-B
• C. Ⅰ-A
• D. Ⅲ-A

Explanation: The given valence shell electronic configuration is 4s2, 4p1. The group number is represented by valence electrons.

• A. CaCl
• B. CaCl₂
• C. Ca2CI2
• D. Ca2CI

Explanation: The electronic configuration of Ca is 1s2 2s2 2p6 3s2 3p6 4s2 3d10. Since, calcium has 20 electrons, it can lose 2 electrons to attain…

• A. Very slow
• B. Moderately slow
• C. Very fast
• D. Not occurs

Explanation: The ionic reactions of inorganic compounds are very fast because these reactions involve combination of opposite ions without involving…

• A. Decreases
• B. Increases
• C. Remains same
• D. Irregular trend

Explanation: Metallic property is ability of an atom to lose electrons to form positive ions.Metallic property in of p-block elements increases because…

• A. M2O
• B. M2O4
• C. MO2
• D. M2O2

Explanation: The oxidation state of superoxide is O2^-½. Hence, the molecular formula will be MO2, where M is M^+1 and O is O^-½.

• A. Potassium
• B. Sodium
• C. Lithium
• D. Calcium

Explanation: Sodium is known to react vigorously with water, producing hydrogen gas and a characteristic yellowish-golden flame.