Acid-base chemistry is classified under three fundamental models: the Arrhenius theory, defining acids as aqueous hydronium ion (H+ / H3O+) donors and bases as hydroxide ion (OH-) donors; the Bronsted-Lowry theory, defining acids as proton donors and bases as proton acceptors forming conjugate pairs; and the Lewis model, defining acids as electron-pair acceptors (e.g., BF3) and bases as electron-pair donors (e.g., NH3). In 1909, S.P.L. Sorensen formulated the logarithmic pH scale, pH = -log10[H+], where neutral solutions at 25 degrees Celsius register pH = 7, acidic solutions < 7, and alkaline solutions > 7. Human arterial blood maintains a strictly buffered homeostatic range between 7.35 and 7.45. Chemical indicators signal equivalence points through visual chromic shifts: litmus (derived from lichens) turns red in acid and blue in base; phenolphthalein shifts from colourless to pink at pH 8.2 to 10.0; and methyl orange transitions from red to yellow across pH 3.1 to 4.4. Neutralization reactions between acids and bases yield salts and water, producing commercially significant compounds including baking soda (NaHCO3), washing soda (Na2CO3.10H2O), bleaching powder (CaOCl2), and Plaster of Paris (CaSO4.0.5H2O).
High-yield conceptual summaries for competitive exams and rapid revision.
Acid-base definitions span Arrhenius (H+/OH- ions in aqueous media), Bronsted-Lowry (proton exchange), and Lewis (electron-pair exchange).
S.P.L. Sorensen introduced the logarithmic pH scale in 1909 (pH = -log10[H+]), where neutral aqueous solutions at 25 degrees Celsius exhibit pH 7.
Human arterial blood pH is tightly regulated within a narrow physiological buffer range of 7.35 to 7.45.
Chemical indicators identify solution acidity: litmus turns red in acid and blue in alkali, phenolphthalein turns pink in base, and methyl orange turns red in acid.
Commercial industrial salts include Bleaching Powder (CaOCl2), Baking Soda (NaHCO3), Washing Soda (Na2CO3.10H2O), and Plaster of Paris (CaSO4.0.5H2O).
Showing 25 Curated Questions239 Total in Bank
1ID: GK-GSCI-00482
easyChemistry in Everyday Life
What is the primary acid present in household vinegar?
Verified Explanation
Vinegar is an aqueous solution containing typically 5% to 8% acetic acid (CH3COOH) by volume, produced by the fermentation of ethanol by acetic acid bacteria.
2ID: GK-COMP-00003
hardDBMS, SQL Basics & File Systems
In database management systems (DBMS), what does the acronym ACID stand for in the context of transaction processing guarantees?
Verified Explanation
ACID transactions guarantee Atomicity (all or nothing), Consistency (preserves database rules), Isolation (concurrent execution without interference), and Durability (committed changes persist even after system failures).
3ID: GK-COMP-00346
easyDBMS, SQL Basics & File Systems
Which ACID property of database transactions guarantees that concurrent execution of multiple transactions results in a system state equivalent to executing them sequentially one after another?
Verified Explanation
Isolation (the 'I' in ACID) ensures that concurrent transaction executions do not interfere with one another and produce the same state as if transactions were executed serially (serializability).
4ID: GK-COMP-00590
mediumDBMS, SQL Basics & File Systems
What do the letters in the acronym 'ACID' represent regarding relational database transaction management?
Verified Explanation
ACID properties ensure reliable database transactions: Atomicity (all or nothing), Consistency (preserves schema rules), Isolation (concurrent execution behaves as serial), and Durability (committed changes persist).
5ID: GK-ENV-00479
easyPollution & Greenhouse Gases
Which two atmospheric pollutants are the primary chemical precursors responsible for causing acid rain?
Verified Explanation
Sulfur dioxide (SO2) and nitrogen oxides (NOx) react with atmospheric water vapour, oxygen, and oxidants to form dilute sulfuric acid (H2SO4) and nitric acid (HNO3), lowering rain pH below 5.6.
6ID: GK-HLTH-00247
hardICMR Guidelines, POSHAN Abhiyaan & Nutrition
Periconceptional maternal supplementation with Folic Acid (Vitamin B9) before and during the first trimester of pregnancy is critically prescribed to prevent which severe congenital malformations?
Verified Explanation
Periconceptional folic acid supplementation (400 mcg daily starting at least 1 month prior to conception and continuing through the first 12 weeks) prevents up to 70% of Neural Tube Defects (NTDs) like anencephaly and spina bifida by ensuring proper embryological closure of the neural tube.
7ID: GK-HLTH-00248
hardICMR Guidelines, POSHAN Abhiyaan & Nutrition
At the molecular level, why does Vitamin C (Ascorbic Acid) deficiency cause the clinical bleeding, spongy gums, and poor wound healing seen in Scurvy?
Verified Explanation
Ascorbic acid acts as an essential electron-donor cofactor for the enzymes prolyl hydroxylase and lysyl hydroxylase. Without Vitamin C, unhydroxylated pro-collagen peptide chains cannot form stable hydrogen bonds to assemble the collagen triple helix, weakening capillary walls and connective tissues.
Deficiency of Vitamin C (ascorbic acid), which impairs collagen synthesis in blood vessels and gums, leads to which classic nutritional deficiency disease?
Verified Explanation
Scurvy is caused by severe deficiency of Vitamin C (ascorbic acid). Because Vitamin C is essential for proline and lysine hydroxylation in collagen synthesis, its deficiency results in fragile capillaries, bleeding gums, skin petechiae, and delayed wound healing.
9ID: GK-GSCI-00026
mediumChemistry in Everyday Life
What is the chemical name of the acid present in vinegar?
Verified Explanation
Commercial vinegar typically contains 5% to 8% acetic acid produced through fermentation by Acetobacter.
10ID: GK-GSCI-00027
mediumChemistry in Everyday Life
The sour taste of curd and yogurt is caused by the presence of which organic acid?
Verified Explanation
Lactobacillus bacteria ferment lactose sugar in milk into lactic acid, which curdles casein proteins.
11ID: GK-GSCI-00158
easyChemistry in Everyday Life
Which inorganic acid is naturally produced in the human stomach to aid digestion and activate pepsin?
Verified Explanation
Parietal cells in the gastric glands of the stomach secrete hydrochloric acid (HCl), creating an acidic environment (pH 1.5-3.5) essential for digestive enzymes.
12ID: GK-GSCI-00163
easyChemistry in Everyday Life
What is the primary organic acid found in household vinegar?
Verified Explanation
Vinegar is typically a 4% to 8% aqueous solution of acetic acid (CH3COOH), produced through the bacterial fermentation of ethanol.
13ID: GK-GSCI-00198
hardChemistry in Everyday Life
According to the Henderson-Hasselbalch equation, what is the pH of an acidic buffer solution composed of equal molar concentrations of acetic acid (CH3COOH) and sodium acetate (CH3COONa), given pKa = 4.76?
Verified Explanation
The Henderson-Hasselbalch equation is pH = pKa + log([Conjugate Base] / [Weak Acid]). When [Base] = [Acid], log(1) = 0, so pH = pKa = 4.76.
14ID: GK-GSCI-00203
easyChemistry in Everyday Life
Which organic acid is naturally predominant in citrus fruits such as lemons, limes, and oranges?
Verified Explanation
Citric acid (C6H8O7) is a weak tricarboxylic organic acid naturally found in high concentrations in citrus fruits.
15ID: GK-GSCI-00257
easyChemistry in Everyday Life
Which acid is naturally present in lemons and oranges giving them their sour taste?
Verified Explanation
Citric acid is a weak organic acid found naturally in citrus fruits like lemons, limes, and oranges.
16ID: GK-GSCI-00262
easyChemistry in Everyday Life
Which gas is evolved when vinegar (acetic acid) reacts with baking soda (sodium bicarbonate)?
Verified Explanation
The reaction between acetic acid and sodium bicarbonate produces sodium acetate, water, and carbon dioxide gas (CO2).
17ID: GK-GSCI-00298
hardBiological Principles & Living Systems
Which unique property of the genetic code ensures that multiple distinct codons can code for the exact same amino acid?
Verified Explanation
The genetic code is degenerate (or redundant) because there are 64 possible triplet codons but only 20 standard amino acids, allowing several codons (wobble base pairing) to specify one amino acid.
18ID: GK-GSCI-00317
easyChemistry in Everyday Life
Which organic tricarboxylic acid is naturally found in citrus fruits like lemons and oranges?
Verified Explanation
Citrus fruits are rich in citric acid (C6H8O7), a weak organic acid that gives them their characteristic sour taste and acts as a natural antioxidant preservative.
19ID: GK-GSCI-00367
easyChemistry in Everyday Life
Which organic acid is naturally present in vinegar?
Verified Explanation
Vinegar is typically a 4% to 8% aqueous solution of ethanoic acid (acetic acid, CH3COOH), produced by the fermentation of ethanol by acetic acid bacteria.
20ID: GK-GSCI-00387
mediumChemistry in Everyday Life
Which synthetic polymer is produced by the step-growth polymerization of hexamethylenediamine and adipic acid?
Verified Explanation
Nylon 6,6 is a polyamide condensation polymer synthesized from two 6-carbon monomers: hexamethylenediamine and adipic acid, releasing water molecules during polymerization.
21ID: GK-GSCI-00417
easyChemistry in Everyday Life
Which acid is naturally present in lemon and orange citrus juices?
Verified Explanation
Citric acid is a tricarboxylic organic acid naturally found in high concentrations in citrus fruits such as lemons, limes, and oranges.
22ID: GK-GSCI-00437
mediumChemistry in Everyday Life
What is the volumetric ratio of concentrated Hydrochloric acid (HCl) to concentrated Nitric acid (HNO3) in 'Aqua Regia'?
Verified Explanation
Aqua Regia is a fuming mixture formed by combining concentrated hydrochloric acid and concentrated nitric acid in a fresh molar/volumetric ratio of 3:1.
23ID: GK-GSCI-00477
easyChemistry in Everyday Life
Which gas is released when dilute hydrochloric acid reacts with active metals such as zinc?
Verified Explanation
When active metals like zinc react with dilute hydrochloric acid, single displacement occurs (Zn + 2HCl -> ZnCl2 + H2), liberating colourless, odorless hydrogen gas which burns with a characteristic pop sound.
24ID: GK-GSCI-00541
easyChemistry in Everyday Life
Which acid is naturally present in sour milk and curd?
Verified Explanation
Lactic acid is produced by the fermentation of milk sugar (lactose) by lactic acid bacteria (Lactobacillus), giving curd its characteristic sour taste.
25ID: GK-GSCI-00576
hardChemistry in Everyday Life
Which synthetic food preservative is chemically known as the sodium salt of benzoic acid (E211), most effective at acidic pH (< 4.5)?
Verified Explanation
Sodium benzoate (C6H5COONa) converts to undissociated benzoic acid in acidic media (pH 2.5–4.0), inhibiting bacterial and fungal growth in pickles, fruit juices, and carbonated drinks.