All Free Chemistry MCQs with Answers

• A. Hg
• B. Pb
• C. Fe
• D. As

Explanation: Lead poisoning is an unusual and frequently overlooked medical complication of gunshot wounds with retained bullet fragments.

• A. Water gas
• B. Coal gas
• C. Producer gas
• D. None of these options

Explanation: Water gas is a source of commercial hydrogen production. It is a mixture of water and carbon monoxide that gives carbon dioxide and…

• A. Reducing
• B. Basic
• C. Hydrating
• D. Sulphonating
• E. Both C and D

Explanation: The explanation for this question will be added soon.

• A. PbO
• B. Pb3O4
• C. Pb2O4
• D. Pb2O5

Explanation: Lead(II, IV) oxide, also called minium, red lead or triplumbic tetroxide, is a bright red or orange crystalline pigment.

• A. Marsh gas
• B. Coal gas
• C. Producer gas
• D. None of these

Explanation: All three options A, B, and C can give hydrogen when reacted with steam however, commercially only the steam-methane reforming method is…

• A. Ammonia
• B. Urea
• C. Di ammonium hydrogen phosphate
• D. Ammonium nitrate

Explanation: Anhydrous ammonia, NH 3, is typically among the least expensive sources of nitrogen and contains 82 percent nitrogen by weight, the…

• A. CaO2
• B. CO2
• C. SnO2
• D. SiO2

Explanation: SnO2 is an amphoteric oxide because it can act as both an acid and a base and react with both acidic and basic solutions to form salts.

• A. Zinc oxide and alumina
• B. Alumina and silica
• C. Silica and Chromium oxide
• D. Zinc oxide and Chromium oxide

Explanation: The industrial preparation of methanol usually involves a catalyst composed of zinc oxide and chromium oxide.

• A. N2
• B. NO2
• C. H2
• D. O2

Explanation: Nitric oxide, NO, reacts with oxygen gas to form nitrogen dioxide, a dark brown gas

• A. CH3CH2CH3CH3CHO
• B. CH3CH2CH2COCH3
• C. CH3CH2CH(CH3)CHO
• D. CH3CH2COCH2CH3

Explanation: b) CH3CH2CH2COCH3:This compound is 2-pentanone, which is a ketone with the molecular formula C5H10O.

• A. Acetaldehyde
• B. Acetone
• C. Aldehydes
• D. Alkene

Explanation: NaBH4 cannot reduce alkenes into alkanes because in a C=C there is no nucleophilic nature, the H- ion needs a positive carbon to attack…

• A. Aldol condensation reaction
• B. Cannizaro reaction
• C. Clemenson condensation reaction
• D. Wolfkishner reaction

Explanation: According to PTB page 237, 50% concentrated NaOH solution is generally used in Cannizaro reaction as it is used for aldehydes which do not…

• A. Formaldehyde
• B. Acetaldehyde
• C. Acetone
• D. Butanone

Explanation: The Cannizzaro reaction is basically a chemical reaction which involves the base-induced disproportionation of an aldehyde lacking a…

• A. Butanal
• B. Methanal
• C. Ethanal
• D. All of these

Explanation: Option A: Butanal, also known as butyraldehyde, is an aldehyde with the chemical formula C4H8O.

• A. Acetaldehyde
• B. 3-hexanone
• C. Butanone
• D. Acetone

Explanation: 3-hexanone does not give the iodoform test. The iodoform test is a chemical test used to detect the presence of methyl ketones.

• A. Nucleophilic
• B. Electrophilic
• C. Neutral
• D. All of these options are correct

Explanation: The carbon present in aldehyde is electrophilic. An electrophile is a molecule or ion that has a partial positive charge and is attracted…

• A. Ketones
• B. Hydrocarbons
• C. Alcohols
• D. Ethers

Explanation: Grignard reagent,R-Mg-X, reacts with carbonyl group in aldehydes to give secondary alcohols with the exception of methanal which gives…

• A. Propanone
• B. 3-Propanone
• C. 2-Butanone.
• D. 2-Propanone.

Explanation: "Propane-2-one," tells us that acetone is a compound with a three-carbon chain (propane) and a ketone functional group (-C=O) on the…

• A. Alkenes
• B. Alkanes
• C. Alkynes
• D. Alcohols

Explanation: Option B is correct since the reduction of aldehydes and ketones to alkanes is done in Wolff Krishner's reaction.

• A. Phenols
• B. Acetone
• C. Ethanal
• D. Methanol

Explanation: Positive iodoform test is given by a methyl ketone or a secondary alcohol with a methyl group in the alpha position.