A Quiz Every Chemistry Student Has To Pass

The correct answer is CH3CH2OH because it is the chemical formula for ethanol, which is a type of alcohol commonly found in alcoholic beverages. The other options listed are not alcohols. CH3OCH3 is dimethyl ether, CH3COOH is acetic acid, and CH3CH2Br is bromoethane.

Urease is not involved in the fermentation of starch. Urease is an enzyme that catalyzes the hydrolysis of urea into carbon dioxide and ammonia. It is not involved in the breakdown of starch into simpler sugars during fermentation. Diastase, zymase, and invertase are all enzymes that are involved in the fermentation process and play a role in breaking down starch into fermentable sugars.

HCLO4 is the strongest acid among the given options. This is because HCLO4, also known as perchloric acid, has the highest acidity due to the presence of four chlorine atoms bonded to a central oxygen atom. The electronegativity of chlorine increases with the addition of more chlorine atoms, making the acid more acidic. Therefore, HCLO4 has the highest acidity and is the strongest acid among the given options.

Grignard reagent is the correct answer because it is a strong nucleophile that can react with both aldehydes and ketones. It adds to the carbonyl group, forming an alcohol as the product. Fehling's reagent and Benedict's reagent are used to test for the presence of reducing sugars, which include aldehydes but not ketones. Tollen's reagent is used to distinguish aldehydes from ketones, as it only reacts with aldehydes to produce a silver mirror.

Clay is not a calcarious material because it is primarily composed of fine particles of minerals such as kaolinite, illite, and montmorillonite. These minerals are formed from the weathering of other rocks and do not contain calcium carbonate, which is the main component of calcarious materials like lime, marble, and marine shell. Therefore, clay does not have the characteristic properties of calcarious materials such as high alkalinity or the ability to effervesce when reacted with acids.

The correct answer is Al2O3.2H2O. This is because Al2O3.2H2O, also known as bauxite, is the chief ore of aluminium. Bauxite is a mixture of hydrated aluminium oxide minerals, including gibbsite (Al2O3.3H2O), boehmite (Al2O3.H2O), and diaspore (Al2O3.H2O). It is the primary source of aluminium and is extensively mined for its aluminium content.

The coordination number of Pt in [PtCl(NO2)(NH3)4] is 6. This is because there are four NH3 ligands and two other ligands, Cl and NO2, making a total of six ligands surrounding the central Pt atom. The coordination number represents the number of ligands attached to the central metal atom or ion in a complex.

The correct answer is NaNO3, which stands for sodium nitrate. Sodium nitrate is commonly known as Chile saltpetre and is used in fertilizers, food preservation, and fireworks. It is a white crystalline solid that is highly soluble in water. The chemical formula NaNO3 indicates that it consists of one sodium (Na) atom, one nitrogen (N) atom, and three oxygen (O) atoms.

In this reaction, acetone (a carbonyl compound) reacts with HCN (a nucleophile) to form a cyanohydrin. The nucleophile attacks the electrophilic carbon of the carbonyl group in acetone, leading to the addition of the nucleophile and the formation of a new carbon-nitrogen bond. This reaction is an example of nucleophilic addition, where a nucleophile adds to a polar or unsaturated bond.

Ethene is the most reactive compound among the given options. This is because ethene contains a double bond between its carbon atoms, which makes it more susceptible to reactions. The double bond is a region of high electron density, making it more attractive to electrophiles and facilitating addition reactions. In contrast, benzene has a stable aromatic ring, ethane has only single bonds, and ethyne has a triple bond, all of which make them less reactive compared to ethene.