Chemistry - Study Mode

[#656] An acid having basicity one is
Correct Answer

(B) Disodium hydrogen phosphate

Explanation

Solution: The basicity of an acid is the number of hydrogen ions (H + ) which can be produced by the ionization of one molecule of the acid in aqueous solution. For example, the basicity of hydrochloric acid is 1 since one molecule of HCl produces one H+ ion in solution. Similarly, the basicity of Disodium phosphate (Na 2 HPO 4 ) is one since it has one H+ displaceable ion.

[#657] The acid present in red ants is
Correct Answer

(D) Formic acid

Explanation

Solution: Formic acid, systematically named methanoic acid, is the simplest carboxylic acid, and has the chemical formula HCOOH. It is an important intermediate in chemical synthesis and occurs naturally, most notably in some ants.

[#658] Bee sting contains
Correct Answer

(A) An acidic liquid

Explanation

Solution: Bee sting contains an acidic liquid.

[#659] Sweat contains water and ________
Correct Answer

(C) Salt

Explanation

Solution: Sweat contains water and dissolved salts. Sweat consists of water and salt. Besides these it also consists of lactic acid, glucose, amino acid and urea.

[#660] The substance most commonly used as a food preservative is
Correct Answer

(D) Sodium salt of benzoic acid

Explanation

Solution: A preservative is a naturally occurring or synthetically produced substance that is added to products such as foods, pharmaceuticals, paints, biological samples, wood, etc. to prevent decomposition by microbial growth or by undesirable chemical changes. Preservative food additives can be used alone or in conjunction with other methods of food preservation. Preservatives may be antimicrobial preservatives, which inhibit the growth of bacteria or fungi, including mold or they can be antioxidants such as oxygen absorbers, which inhibit the oxidation of food constituents. Common antimicrobial preservatives include sorbic acid and its salts, benzoic acid and its salts, calcium propionate, sodium nitrite (and sodium nitrate which converts to sodium nitrite “in situ”), sulfites (sulfur dioxide, sodium bisulfite, potassium hydrogen sulfite, etc.) and disodium EDTA.