Chemistry Section 14

---

• The correct atomic weight sequence is Co > Ni > Fe.
• The limit of the visible spectrum is 3800 to 7600 A°.
• The wave-number of the second line in the Lyman series is 3R/4.
• The magnetic quantum number specifies the orientation of orbitals.
• The azimuthal quantum number defines the angular momentum of an electron.
• The energy of one mole of photons with a frequency of 4×10^14 Hz is 159.6 kJ.
• Helium (He) shows more ideal behavior at 0°C.
• When a gas is heated from 300K to 600K at constant pressure, its kinetic energy becomes double.
• The volume of gas becomes twice at 546 K when pressure is constant.
• The gas with a density of 1.964 g dm^-3 at 273 K and 76 cm Hg is CO2.
• (CH3)3CBr is hydrolyzed by SN1 mechanism.
• Grignard reagent is treated with H2O to form hydrocarbon.
• Grignard reagent gives carboxylic acid with CO2.
• The law of traids is applicable to Cl, Br, I.
• The concept of telluric helix was developed by A.E de Chancourtois.
• Elements in group 18 exist as monoatomic molecules.
• The element with electronic configuration [kr] 4d10, 4f14, 5s2, 5p6, 5d1, 6s2 belongs to the f-block.
• The bridge element among the options is Be.
• The common oxidation state of lanthanides is +3.
• The most soluble substance in water among the options is MgSO4.
• The aqueous solution with the highest boiling point is 0.15 m CaCl2.
• The mass of 3.2 moles of ammonia (NH3) gas is 54.4 grams.
• The moles in 22.2 grams of Calcium chloride (CaCl2) are 0.2 moles.
• The mass percent of silver in AgNO3 is 63.5%.
• The percent of iron in the ore with a mass of 35.8 grams and iron mass of 27.9 grams is 78% Fe.
• The molecular formula of a compound with empirical formula C2H6O and molar mass 138 g/mole is C6H18O3.
• The molecular formula of a compound with empirical formula CH2 and molar mass 56 g/mole is C4H8.
• The density of argon gas at 30°C and 1.05 atm is 1.68 g/L.
• Ethyl Mercaptan (C6H5-CO-CH3) is used as an indicator in volumetric analysis.
• The poisonous gas in jet plane exhaust fumes is carbon monoxide (CO).
• The O-O linkage is present in H2SO8.
• The number of lone pairs in XeOF4 is 1.
• Argon gas was discovered by Ramsay.
• SO2 reacts with Cl in sunlight to form Sulphuryl chloride.
• The oxidation state +1 for phosphorus is found in H3PO2.
• The electric bulb filament is made of tungsten.
• Tetraethyl lead is used as a petrol additive.
• The average salinity of seawater is 3.5%.
• Ethyl Mercaptan is added to LPG cooking gas for imparting a detectable smell.
• Marsh gas is methane (CH4).
• Potassium Permanganate is used for purifying drinking water as an oxidizing agent.
• The pH of a 0.001 M solution of Nitric acid (HNO3) is 3.
• The set of quantum numbers not allowed is n=2, l=2, m1=1, ms=-1/2.
• Smelting is used to reduce an ore.
• MnO2 is the amphoteric oxide of manganese.
• Forth flotation is a process used for the concentration of ore.
• Carbon is used as a reducing agent in smelting.
• Parke’s process is used in the extraction of silver.
• In the extraction of iron, the reaction Fe2O3+3CO forms 2Fe+3CO2.
• The formula of Gypsum is CaSO4.2H2O.
• Orthophosphoric acid has a basicity of 3.
• The electronic configuration of Calcium (Ca) atom is Ar, 4s2.
• The chemical symbol for Tungsten is W.
• The composition of ‘Golden spangles’ is PbCrO4.
• The lead pencil does not contain any percentage of lead; it’s a misconception.
• The compound formed in the Borax bead test is Metaborate.
• Noble gases are called zero group elements because they have both zero valency and zero electronegativity.
• The chemical symbol for Tungsten is W.
• The compound Galena has the formula PbS.
• The percentage of lead in a lead pencil is actually zero; there is no lead present in pencils.
• In the Borax bead test, a Metaborate compound is formed.
• Water molecule has a V-shaped geometry.
• The shape of I3- (tri-iodine) ion is linear.
• BeCl2 has a hybridization of type Sp.
• Molecular Orbital Theory is also called Antibonding theory.
• The formula for Cassiterite, an ore of tin, is SnO2.
• The percentage of gold in ‘Golden spangles’ is zero; it does not contain gold.
• Ethylene diamine is a bidentate ligand.
• Methyl orange indicator is used when the acid is strong.
• The reaction 2HI ⇌ H2 + I2 follows Kp = Kc relationship.
• Lucas reagent reacts the fastest with (CH3)3COH.
• The empirical formula for the compound with 24g carbon, 2g hydrogen, and 64g oxygen is CHO2.
• Noble gases are called zero group elements due to their zero valency and zero electronegativity.
• The element with the chemical symbol W is Tungsten.
• The composition of ‘Golden spangles’ is PbCrO4.
• Passing SO2 solution over K2Cr2O7 turns it green.
• If a bivalent metal has an equivalent weight of 12, its oxide’s molecular weight will be 40.
• The weight of a metal with an equivalent of 12 that gives 0.475g of its chloride is 0.18g.
• To produce 224 ml of H2 by reacting with an acid, 7.5g of Zinc (at. Wt=65) is required.
• AgCl is not soluble in HNO3.
• Curd in water is formed by the anions of soap, Sodium hexadecanoate and Sodium octadecanoate.
• Nitrogen atom in pyridine has Sp2 hybridization.
• The IUPAC name for pyridine is Azine.
• There are 16 isomeric aldoses possible for the molecular formula C6H12O6.
• The systematic name of sucrose is 1-α-D- glucopyranosyl-2-β-D-fructopyranoside.
• Treatment of sucrose with conc. HNO3 results in Nitrosucrose.
• Alpha (α) particles are helium (He) nuclei with a charge of 2e.
• Elements emitting natural radioactivity are known as radioactive elements.
• An alpha particle is a helium nucleus comprising two protons and two neutrons with a charge of 2e.
• In SI base units, 1 Bq is equal to 1 disintegration per second.
• Enzymes are examples of ‘globular’ proteins.
• Steel tubes are used when ammonia is used as a refrigerant in a vapor compression cycle.
• The solution remaining after crystal formation is called the mother liquor.
• Rayon is an artificial manmade fiber.
• Human brain and heart are composed of 73% water.
• Carbon, Diamond, and Graphite are together called allotropes.
• Actinides are elements with atomic numbers from 89 to 103.
• A falling barometer indicates rainfall.
• One fathom is equal to 6 feet.
• Metal-bearing rocks are called ores.
• Soil pollution is caused by acid rain.
• Radiation causes skin cancer.
• The practical problem in hydrogen production is its weight.
• [Pt(NH3)]Cl2 produces 3 ions.
• Stone is a solid substance.
• Barrett’s esophagus is an example of metaplasia.
• Ethylene gas is used for artificial ripening of green fruit.
• Phonon is the quantum of an elastic wave.
• The concept of ensemble was introduced by Gibbs.
• Water has stronger London dispersion forces.
• Urea as a fertilizer contains 46% N.
• Honey is the most viscous substance.
• Aufbau’s principle is not the name of any scientist.
• Animal wastes are commonly used for the generation of biogas.
• The electronic configuration of Sodium is 1s2,2s2,2p6,3s1.
• Air is a mixture.
• The elements used for the formation of alloys include Chromium.
• The bond energy of H-F is 562 kJ/mol.
• Benzene gives mainly substitution reactions.
• The chemical formula of sand is SiO2.
• Sand and Naphthalene can be separated by the sublimation method.
• The boiling point of a liquid is determined to check its purity and nature.
• Ethyl alcohol shows a high boiling point due to hydrogen bonding.
• The boiling point of ethyl alcohol is 78°C.
• Sublimation is the process in which solid changes directly into vapors without passing through the liquid state.
• The pH of milk is 6.5-7.
• The % of N in KNO3 is 13.86%.
• Isotone refers to elements that have the same number of neutrons.
• Schwartz introduced the term “Concentration window” for drawing arbitrary lines of demarcation.
• Algae serves as an aquatic solar fuel cell.
• One-third of the solar flux absorbed by Earth’s surface is used to drive the hydrologic cycle.
• Polyamides are synthetic polymers commonly known as Nylon.
• The rate of ozone formation depends on the flux of ultraviolet radiation.
• Traffic policemen on duty at busy street crossings during heavy traffic rush hours are advised to use oxygen tanks.
• Earth absorbs radiation in the visible range but emits radiation at the same rate in the infrared.
• The mass of one mole of Iodine is 254g.
• Atoms of all elements always contain protons in the nucleus.
• Chemistry is derived from the Greek language.
• A metallic atom loses its valence electron to form a cation.
• An acid-base reaction is always exothermic.
• The size of Na+ ion is smaller than the size of a Na atom.
• Urea is a synthetic fertilizer.
• All metals do not form acidic oxides.
• The smallest particle that is indivisible is an atom.
• Diamond is one of the allotropic modifications of carbon.
• When radiation of light passes through a prism, it undergoes refraction.
• Petra means rock.
• The radiations with the highest speed are gamma radiations.
• Radiations with negative charge are beta radiations.
• The discovery of proton resulted from the process of canal rays.
• Nitrate (NO3) ions are obtained by the process of nitrification.
• Hookworm is a parasitic worm that infects the small intestine.