Description : Explain the stability of carbonates & bicarbonates of alkali metals .
Last Answer : The alkali metals form salts with all the oxo-acids. They are generally soluble in water and thermally stable. Their carbonates (M2CO3) and in most cases the hydrogencarbonates (MHCO3) also are highly ... the formation of more stable Li2O and CO2. Its hydrogencarbonate does not exist as a solid.
Description : If the heat of solution of an ideal gas in a liquid is negative, then its solubility at a given partial pressure varies with the temperature as (A) Solubility increases as temperature ... (D) Solubility increases or decreases with temperature depending on the Gibbs free energy change of solution
Last Answer : (B) Solubility increases as temperature decreases
Description : Amongst the various ores of a metal (M) (sulphide, carbonates, oxides, hydrated or hydroxides) two ores [X] and [Y] show the following reactivity. (i)
Last Answer : Amongst the various ores of a metal (M) (sulphide, carbonates, oxides, hydrated or hydroxides) ... and hydroxide ores D. Carbonate and oxide ores
Description : With increase in temperature, the solubility of gases in liquids, at fixed pressure (A) Increases (B) Decreases (C) Remain same (D) Either (A) or (B), depends on the system
Last Answer : (B) Decreases
Description : With increase in temperature, the mutual solubility of two liquids (A) Increases (B) Decreases (C) Remains unchanged (D) Decreases exponentially
Last Answer : (A) Increases
Description : A negative heat of solution indicates that: w) an endothermic dissolving process occurs x) solute solubility increases with rising solution temperature y) solute solubility decreases with rising solution temperature z) super-saturation conditions exist
Last Answer : ANSWER: Y -- SOLUTE SOLUBILITY DECREASES WITH RISING SOLUTION TEMPERATURE
Description : When the wavelength of incident X-rays increases, the angle of diffraction (A) Decreases (B) Increases (C) Remain constant (D) Shows no systematic variation
Last Answer : Option A
Description : Diamond is chemically (a) a mixture of metal carbonates (b) pure carbon (c) a pure form of sand (d) a mixture of calcium and magnesium phosphates
Last Answer : Ans:(b)
Description : Metal carbonates decompose on heating to give metal oxide and carbon dioxide. Which of the metal carbonates is most stable thermally?
Last Answer : Metal carbonates decompose on heating to give metal oxide and carbon dioxide. Which of the metal carbonates is most ... C. `SrCO_(3)` D. `BaCO_(3)`
Description : Which of the following metal carbonates liberate. `CO_(2)(g)` on heating :
Last Answer : Which of the following metal carbonates liberate. `CO_(2)(g)` on heating : A. `Na_(2)CO_(3)` B. `K_(2)CO_(3)` C. `Rb_(2)CO_(3)` D. `Ag_(2)CO_(3)`
Description : How many of the following are metal carbonates : Dolomite ,Malachite ,Azurite ,Siderite Calamine , Magnasite ,Limestone ,Washing soda ,Cerussite
Last Answer : How many of the following are metal carbonates : Dolomite ,Malachite ,Azurite ,Siderite Calamine , Magnasite ,Limestone ,Washing soda ,Cerussite
Description : Choose the correct statement. (a) Electronegativity increases down a group (b) Electronegativity decreases down a group (c) Electronegativity decreases from left to right along a period (d) Electronegativity changes along a group, but remains constant along a period
Description : Assertion :- Metallic character increases on going down the group Reason :- I.E. decreases on going down the group
Last Answer : Assertion :- Metallic character increases on going down the group Reason :- I.E. decreases on going ... . D. If both Assertion & Reason are false
Description : When the nurse observes that the patient's heart rate increases during inspiration and decreases during expiration, the nurse reports that the patient is demonstrating a) sinus dysrhythmia. Sinus dysrhythmia ... occurs when the sinus node regularly creates an impulse at a faster-than-normal rate.
Last Answer : a) sinus dysrhythmia. Sinus dysrhythmia occurs when the sinus node creates an impulse at an irregular rhythm.
Description : What is the reason for the increasing stability of peroxide & superoxide of alkali metals down the group?
Last Answer : On combustion in excess of air, lithium forms mainly the oxide, Li2O (plus some peroxide Li2O2), sodium forms the peroxide, Na2O2 (and some superoxide NaO2) whilst potassium, rubidium and ... are also paramagnetic. Sodium peroxide is widely used as an oxidising agent in inorganic chemistry.
Description : Pick out the wrong statement regarding the solubility characteristics of high polymers. (A) Greater the degree of cross-linking in the polymer, lesser is its solubility (B) Polymers having more ... of the solvent (D) High molecular weight polymers on dissolving gives solution of very low viscosity
Last Answer : (D) High molecular weight polymers on dissolving gives solution of very low viscosity
Description : Why does solubility decreases with increasing molecular mass in carboxylic acid ?
Last Answer : Ans. Because of increase in alkyl chain length which is hydrophobic in nature.
Description : On increasing the temperature the solubility of most of the gases in water decreases. An important consequence of this effect is the thermal pollution of water, such as occurs around power plants cooled by a river or stream. How is the survival of fish affected by thermal pollution of water?
Last Answer : Ans.: When the water temperature of the river or stream is increases the solubility of oxygen in water decreases. Due to this decrease in dissolved oxygen the survival of fish becomes difficult.
Description : For concentrating an aqueous solution of a material like anhydrous Na2SO4, whose solubility decreases with rise in temperature, the most suitable evaporator is a __________ evaporator. (A) High pressure (B) Vacuum (C) Backward feed (D) None of these
Last Answer : (B) Vacuum
Description : What are the four main classes of regular variation which affect the extent of ionization in the ionosphere?
Last Answer : Daily, seasonal, 11-year, and 27-days variation
Description : Pick out the wrong statement. (A) Linear polymers are formed from bifunctional groups only and are normally thermoplastic (B) Cross-linked branched chain polymers are either elastometric or ... (D) Dibasic acids reacts with dihydric alcohols to give polyesters using addition polymerisation reaction
Last Answer : D) Dibasic acids reacts with dihydric alcohols to give polyesters using addition polymerisation reaction
Description : Pick out the wrong statement. (A) In solvent extraction, the distribution co-efficient should be as large as possible for solvent economy (B) With increase in pressure, the solubility of ... in distillation column (D) The capacity of a distillation column is maximum at total reflux
Last Answer : (D) The capacity of a distillation column is maximum at total reflux
Description : When acetone is added in a two layer mixture of methyl isobutyl ketone and water at 30°C, the acetone distributes between the two layers and the composition of the layer follows two solubility curves. For this system ... at the concentration of the plait point (D) All (A), (B) and (C
Last Answer : (D) All (A), (B) and (C
Description : Pick out the wrong statement. (A) At constant pressure, solubility of a gas in a liquid diminishes with rise in temperature (B) Normally, the gases which are easily liquefied are more soluble ... (D) At constant pressure, solubility of a gas in a liquid increases with rise in temperature
Last Answer : (A) At constant pressure, solubility of a gas in a liquid diminishes with rise in temperature
Description : As you go down into a well, your weight: w) increases slightly x) decreases slightly y) remains exactly the same
Last Answer : ANSWER: X -- DECREASES SLIGHTLY
Description : If there is a circular hole in a metal plate, what happens to the radius of the hole when the plate is heated? (1) Increases (2) Decreases (3) Unchanged (4) Depends upon the metal
Last Answer : (1) Increases Explanation: When a metal plate with a circular hole at its centre is heated, definitely along with the areal expansion of the plate the diameter of the circular hole also increases. Using ... of expansions, we find that the hole radius increases at the same linear rate as the metal.
Last Answer : Increases
Description : Which of the following statements about total body water composition are correct? A. Females and obese persons have an increased percentage of body water. B. Increased muscle mass is associated with ... age. E. Any person's percentage of body water is subject to wide physiologic variation.
Last Answer : Answer: CD DISCUSSION: Since fat contains little water, lean persons with a proportionately greater muscle mass have a greater than expected volume of total body water. Likewise, the ... decreases steadily and significantly with age. The actual figure for a healthy person is remarkably constant
Description : For all positive reaction orders for a particular duty, (A) Mixed reactor is always larger than the plug-flow reactor (B) Ratio of the volume of the mixed reactor to that of the plug-flow ... (C) Reactor size is independent of the type of flow (D) Density variation during reaction affects design
Last Answer : (A) Mixed reactor is always larger than the plug-flow reactor
Description : How can you show the effect of pressure on the solubility of carbon dioxide gas in water?
Last Answer : Feel Free to Answer
Description : The antibodies raised against a pure protein will show only one sharp spike on this technique: (A) Solubility curve (B) Solvent precipitation (C) Molecular weight determination (D) Immuno electrophoresis
Last Answer : Answer : D
Description : All the following statements about ketone bodies are true except (A) Their synthesis increases in diabetes mellitus (B) They are synthesized in mitchondria (C) They can deplete the alkali reserve (D) They can be oxidized in the liver
Description : Which of the following properties is not true for an alkali metal? (a) Low electronegativity (b) Low ionisation energy (c) Low atomic volume (d) Low density
Last Answer : Ans:(c)
Description : Most abundant alkali metal is?
Last Answer : Sodium (Na)
Description : Which alkali metal is denser than water?
Last Answer : Lithium
Description : The metal shows the characteristics of both acid and alkali?
Last Answer : Aluminium
Description : What is the most electrically positive and active metal of the alkali metal period ?
Last Answer : Alkali metal is the most electrically positive and active metal of all time .
Description : What is alkali metal ?
Last Answer : The first class elements of a periodic table are called alkali metals.
Last Answer : Copper ' Of alkali With Reaction By No.
Description : Which of the following alkali metal ions has the lowest ionic mobility in aqueous solutions?
Last Answer : Which of the following alkali metal ions has the lowest ionic mobility in aqueous solutions? A. `Li^(+)` B. `Na^(+)` C. `Rb^(+)` D. `Cs^(+)`
Description : The ease of adsorption of the hydrated alkali metal ions on ion-exchange resins follows the order:
Last Answer : The ease of adsorption of the hydrated alkali metal ions on ion-exchange resins follows the order: A. `K^(+)lt Na + ... (+)lt K^(+)lt Na^(+)lt Li^(+)`
Description : Alkali metal hydrogen fluorides have a formula `M[HF_2]`. They are found to contain a linear symmetrical anion having an overall F—H—F distance of 2.2
Last Answer : Alkali metal hydrogen fluorides have a formula `M[HF_2]`. They are found to contain a linear symmetrical ... F-atoms through two T bonds in the anion.
Description : Alkali metal salt "X" gives a pale violet colour in flame test "X" is :
Last Answer : Alkali metal salt "X" gives a pale violet colour in flame test "X" is : A. NaCl B. LiCl C. KCl D. None of these
Description : `Mf + XeF_(4) rarr M^(+) A^(-) (M^(+)-` alkali metal cation) The state of hybridisation of the central atom in A and sphere of the species are:
Last Answer : `Mf + XeF_(4) rarr M^(+) A^(-) (M^(+)-` alkali metal cation) The state of hybridisation of ... )d^(3)`, pentagonal planar D. no compound formed at all
Description : Why alkali metal have low ionization energy?
Last Answer : Ionization energy is the energy required to remove an electronfrom an atom or ion. Low ionization energy indicates that it takesless energy to remove an electron from the atom. The alkali ... are more and more electrons in theoutermost energy level, requiring more energy to remove anelectron.
Description : Which element is in the alkali metal family?
Last Answer : Lithium (Li) APEX
Description : An element with an atomic number of 17 is - (1) an alkali metal (2) a rare gas (3) a halogen gas (4) a transition metal
Last Answer : (3) a halogen gas Explanation: Chlorine has atomic number of 17. It is a halogen gas along with fluorine (F), bromine (Br), iodine (I), and astatine (At).
Description : Arrange the following in order of the increasing covalent character : MCl,MBr,MF,MI ( Where M=alkali metal)
Last Answer : Ans. MF < MCI < MB < MI
Description : when an alkali metal dissolves in liquid ammonia, the solution can acquire different colors. Explain .
Last Answer : Ans. The dilute solutions of alkali metals in liquid ammonia exhibit dark blue color because ammoniated electrons absorb energy corresponding the red region of the visible light. However, If the ... copper-bronze and the solution acquires metallic luster due to the formation of metal ion clusters.