All Free Chemistry MCQs with Answers

• A. A catalyst
• B. A Lewis acid
• C. An electron deficient specie
• D. All of the above

Explanation: AlBr3 is used as a catalyst, it is a lewis acid i.e is an electron-pair acceptor therefore it is also an electron deficient species so…

• A. Redox reaction
• B. Acid base reaction
• C. Substitution reaction
• D. Decomposition reaction

Explanation: The reaction is 'decomposition' as one mole of water is removed to form the hydronium ion

• A. Ethylene
• B. Acetylene
• C. Benzene
• D. All have equal strength

Explanation: Acetylene (ethyne) has a triple bond between the carbon atoms, allowing it to donate a pair of electrons more readily compared to…

• A. Sulphate ion
• B. Hydroxyl ion
• C. Per chlorate ion
• D. Iodide ion

Explanation: The hydroxyl ion (OH-) is a strong conjugate base. It readily accepts a proton (H+) to form water (H2O).

• A. 43
• B. 48
• C. 0.43
• D. 4.3

Explanation: pH=pKa+ Log NaHCO3/H2CO3 7=4.3*10^-7+ Log NaHCO3/H2CO3 Log NaHCO3/H2CO3=7 NaHCO3/H2CO3=10^7 NaHCO3=10^7* H2C03 NaHCO3=10^7*4.3^-7 NaHCO3=4.3

• A. pH = pKa + log([Acid]/[Salt])
• B. pH = pKa - log([Salt]/[Acid])
• C. pH = pKa + log([Salt]/[Acid])
• D. pH = pKa - log([Acid]/[Salt])

Explanation: Henderson-Hasselbalch equation to calculate the pH of a buffer solution ispH=pka+log[salt]/[Acid]

• A. P2O5
• B. H2SO4
• C. +CH3COONa
• D. CH3COOH

Explanation: Acetyl chloride reacts with sodium acetate to give acetic anhydride.

• A. Ester
• B. Amide
• C. Anhydride
• D. Amine

Explanation: Amines are derivatives of ammonia where H is replaced by one or more alkyl or aryl groups.

• A. Steroids
• B. Carbohydrates
• C. Vitamins
• D. Soap

Explanation: The formula CH3(CH2)14COO-Na represents a soap compound. Soaps are salts of fatty acids and are commonly used for cleaning purposes.

• A. Steroids
• B. Soaps
• C. Carbohydrates
• D. Vitamins

Explanation: The formula CH3(CH2)16COO-Na+ represents a compound known as soap.

• A. H2NCONH2
• B. NH4COONH4
• C. H2NCOONH2
• D. NH2COONH4

Explanation: The formula of ammonium carbamate is NH2COONH4.

• A. high acidity
• B. high basicity
• C. neutrality
• D. high temperature

Explanation: An ester is a compound derived from an oxoacid (organic or inorganic) in which at least one hydroxyl group (−OH) is replaced by an alkoxy…

• A. CH3COOH and CH3OCH3
• B. CH3COOH and C2H5OH
• C. CH3COOH and CH3CHO
• D. CH3COOH and CH3COCH3

Explanation: When primary alcohol is treated with a carboxylic acid in the presence of sulphuric acid a compound is formed.

• A. Esterificatoon
• B. Decarboxylation
• C. Saponification
• D. Transesterification

Explanation: Saponification is the process of hydrolyzing an ester in the presence of an alkali, typically sodium hydroxide (NaOH).

• A. Stabilize acid halides
• B. Consume HCl formed in the reaction
• C. Dehydrate alcohol
• D. Dehydrogenate acid halides

Explanation: This option is correct. During the reaction of acid halides with alcohols to form esters, hydrogen halide (such as HCl) is released as a…

• A. Methanoic acid
• B. Chloro methane
• C. Methanoyl chloride
• D. Chloro methanoate

Explanation: The correct IUPAC name for formyl chloride is Methanoyl chloride. This name indicates that the compound is derived from methane (the…

• A. Daltons Law
• B. Boyle's Law
• C. Avogadro's Law
• D. Charles law

Explanation: Charles' Law states that, at constant pressure, the volume of a fixed mass of gas is directly proportional to the absolute temperature.

• A. Alcohol
• B. Adeline
• C. Piece of paper
• D. Water absorbed on paper

Explanation: Water absorbed on paper: This option is correct. In paper chromatography, the stationary phase is usually achieved by impregnating the…

• A. Paper chromatography is an example of partition chromatography.
• B. Paper chromatography is most commonly used to separate biologically active substances.
• C. Paper chromatography can also be applied for separating some inorganic ions.
• D. Paper chromatography is always used for quantitative analysis.

Explanation: There are limitations to paper chromatography that include;Large quantities of sample cannot be applied on paper chromatography.In…

• A. Multiple bonds
• B. Hybridization
• C. Long chain or rings of carbon atoms
• D. Showing isomerism

Explanation: Catenation is the bonding of atoms of the same element into a series, called a chain.