What is alkali ?

What is alkali ?
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1 Answer

Answer :

The compounds that react with acids to produce salts and water are called bases.
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Related questions

What is 'acid and alkali' according to scientist Lewis ?

Description : What is 'acid and alkali' according to scientist Lewis ?

Last Answer : Lewis, the scientist who advocated the electronic doctrine of acid and alkali. According to his theory, the compound that receives electrons is called acid. And the compound that rejects electrons is called alkali.

What are the alkali metals ?

Description : What are the alkali metals ?

Last Answer : The remaining 6 elements of hydrogen in group 1 of the periodic table .

What is the nature of acid deficient alkali ?

Description : What is the nature of acid deficient alkali ?

Last Answer : The stronger the acid , the more proton it tends to drop. Then the tendency of the acid-binding base to bind to protons is very low. That is, it is mildly alkaline. Conversely, mild acids are ... it is highly alkaline. Thus the acid-binding base is mild and the mild acid-binding base is intense.

Why Copper Oxide Is Not Alkali ?

Description : Why Copper Oxide Is Not Alkali ?

Last Answer : Substances that soothe the acid and destroy its characteristic properties are therefore alkaline. Alkalis are those substances which dissolve in water. Copper oxide only soothes the acid and eliminates its characteristic ... , but it does not dissolve in water. So copper oxide is not an alkali.

What is the difference between alkali and alkali ?

Description : What is the difference between alkali and alkali ?

Last Answer : Alkalis are a class of chemical compounds that are capable of absorbing hydrogen ions. Such as metal oxides or hydroxides are alkalis. Water-soluble alkalis that provide hydroxide ions ( OH−) are called alkalis ... is why it is said that not all alkalis are alkalis , but all alkalis are alkalis.

What is alkali ?

Description : What is alkali ?

Last Answer : Alkalis that give hydrochloride ( OH-) ions in aqueous solution are called alkalis

What is alkali metal ?

Description : What is alkali metal ?

Last Answer : The first class elements of a periodic table are called alkali metals.

Iodine value is used to estimate – (1) Hydroxyl groups in oil (2) Alkali, content in oil (3) Unsaturation in oil (4) Carboxylic groups in oil

Description : Iodine value is used to estimate – (1) Hydroxyl groups in oil (2) Alkali, content in oil (3) Unsaturation in oil (4) Carboxylic groups in oil

Last Answer : (3) Unsaturation in oil Explanation: Iodine value is used to estimate unsatwation in oil.

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

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).

0.257g of organic substance was heated with conc. sulphuric acid and then distilled with excess of strong alkali .the ammonia gas evolved was absorbed in 50ml of .1M HCl which required 23.2ml of c for neutralization at the end of the process. Determine the % of nitrogen in the compound ?

Description : 0.257g of organic substance was heated with conc. sulphuric acid and then distilled with excess of strong alkali .the ammonia gas evolved was absorbed in 50ml of .1M HCl which required 23.2ml of c for neutralization at the end of the process. Determine the % of nitrogen in the compound ?

Last Answer : A. Vol of 0 .1M HCl taken = 50ml Vol of .1MNaOH used for neutralization of unused acid=23.2ml Now, 23.2 ml of .1MNaOH =23.2ml of .1MHCl Vol of .1MHCl unused=23.2ml Vol of .1MHCl required ... NH3 solution contain nitrogen = 14*26.8/10*1000 Percentage of Nitrogen=14*26.8*100/10*1000*.257 =14.6%

How does the of Hydration Enthalpy of alkaline earth metals vary & compare it with alkali metals

Description : How does the of Hydration Enthalpy of alkaline earth metals vary & compare it with alkali metals

Last Answer : Ans The hydration enthalpies of alkaline earth metal ions decrease with increase in ionic size down the group. Be2+> Mg2+ > Ca2+ > Sr2+ > Ba2+ The hydration enthalpies of alkaline earth metal ions ... MgCl2 and CaCl2 exist as MgCl2.6H2O and CaCl2· 6H2O while NaCl and KCl do not form such hydrates.

How does the of Ionization Enthalpy of alkaline earth metals vary in comparison to alkali metals

Description : How does the of Ionization Enthalpy of alkaline earth metals vary in comparison to alkali metals

Last Answer : Ans The alkaline earth metals have low ionization enthalpies due to fairly large size of the atoms. Since the atomic size increases down the group, their ionization enthalpy decreases The first ... enthalpies of the alkaline earth metals are smaller than those of the corresponding alkali metals.

How does the atomic and Ionic Radii of alkaline earth metals vary in comparison to alkali metals

Description : How does the atomic and Ionic Radii of alkaline earth metals vary in comparison to alkali metals

Last Answer : Ans The atomic and ionic radii of the alkaline earth metals are smaller than those of the corresponding alkali metals in the same periods. This is due to the increased nuclear charge in these elements. Within the group, the atomic and ionic radii increase with increase in atomic number.

Give reason .the compounds of alkaline earth metals are less ionic than alkali metals

Description : Give reason .the compounds of alkaline earth metals are less ionic than alkali metals

Last Answer : Ans This is due to increased nuclear charge and smaller size.

Arrange the following in order of the increasing covalent character : MCl,MBr,MF,MI ( Where M=alkali metal)

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

Give reason for the following: (i)alkali metals do not occur free in nature. (ii)alkali metals have low I .E. (iii)LiI is more soluble than KI in ethanol.

Description : Give reason for the following: (i)alkali metals do not occur free in nature. (ii)alkali metals have low I .E. (iii)LiI is more soluble than KI in ethanol.

Last Answer : Ans.(i)They are highly reactive in natur (ii) Because of large atomic size. (III)LiI is more covalent in character than KI

when an alkali metal dissolves in liquid ammonia, the solution can acquire different colors. Explain .

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.

State as to why: (a) A solution of Na2CO3 is alkaline? (b)alkali metals are prepared by electrolysis of their fused chlorides ? (c)sodium is found to be more useful than potassium ?

Description : State as to why: (a) A solution of Na2CO3 is alkaline? (b)alkali metals are prepared by electrolysis of their fused chlorides ? (c)sodium is found to be more useful than potassium ?

Last Answer : Ans. (a) It undergoes hydrolysis to produce a strong base NaOH . (b) When the aq. Solution of any alkali metal is subjected to electrolysis ,H2 instead of the alkali metal is produced at the ... of sugars and amino acids into the cells. Thus, sodium is found to be more useful than potassium.

why alkali metals impart color to the flame?

Description : why alkali metals impart color to the flame?

Last Answer : Ans. Alkali metals have low ionization enththalpies. Their valence electrons get excited by absorbing energy from the flame. When these electrons return to the ground state, the energy is emitted In the form of light.

Which alkali metal has the highest ionic radii ?

Description : Which alkali metal has the highest ionic radii ?

Last Answer : Ans.Cs.

Which alkali metal will have highest hydration enthalpy ?

Description : Which alkali metal will have highest hydration enthalpy ?

Last Answer : Ans. Li

what are the common physical features of alkali metals?

Description : what are the common physical features of alkali metals?

Last Answer : Ans. Large Atomic and ionic radii, Low ionization enthalpies, metallic character, low melting and boiling Point, form ionic bond, low density,show flame coloration ,photoelectric effect.

When a cation is highly polarizing ? Which alkali metal cation has the highest polarizing power ?

Description : When a cation is highly polarizing ? Which alkali metal cation has the highest polarizing power ?

Last Answer : Ans. A cation is highly polarizing if its charge/size ratio is very high.Li+ has the highest polarizing power .

Name the alkali metal which forms only the normal oxide on heating with air ?

Description : Name the alkali metal which forms only the normal oxide on heating with air ?

Last Answer : Ans. Li.

Name the alkali metal which shows diagonal relationship with Mg?

Description : Name the alkali metal which shows diagonal relationship with Mg?

Last Answer : Ans.Li

what do you understand by “Non stoichiometric hydrides”? Do you think this type of hydrides to be formed by alkali metals? Justify your answer.

Description : what do you understand by “Non stoichiometric hydrides”? Do you think this type of hydrides to be formed by alkali metals? Justify your answer.

Last Answer : Ans: Hydrides which are deficient in hydrogen and in which the ratio of hydrogen to metal is fractional are called non-stoichiometric hydrides. This type of hydrides are formed by d-and ... they form only stoichiometric hydrides. In other words alkali metals do not form non-stoichiometric hydrides.

Give point of resemblance of hydrogen with alkali metal.

Description : Give point of resemblance of hydrogen with alkali metal.

Last Answer : Ans: 1 like alkali metals hydrogen also has one electron in its valence shell 2 like alkali metals hydrogen loses its only electron to form proton(H+) 3 like alkalis metals hydrogen ... the same way as alkali metals are librated at the cathode during the electrolysis of their fused halides

Give reason for the appearance of colour in alkali metal halides.

Description : Give reason for the appearance of colour in alkali metal halides. 

Last Answer : Due to F-centres.

Which one of the alkali metals, forms only, the normal oxide, M2O on heating in air (1) Na (2) Rb (3) K (4) Li

Description : Which one of the alkali metals, forms only, the normal oxide, M2O on heating in air (1) Na (2) Rb (3) K (4) Li

Last Answer : Li

Buffer solutions have constant acidity and alkalinity because: (1) they have fixed value of pH (2) these give unionised acid or base on reaction with added acid or alkali (3) acids and alkalies in these solutions are shielded from attack by other ions (4) they have large excess of H+ or OH– ions

Description : Buffer solutions have constant acidity and alkalinity because: (1) they have fixed value of pH (2) these give unionised acid or base on reaction with added acid or alkali (3) acids and alkalies in these solutions are shielded from attack by other ions (4) they have large excess of H+ or OH– ions

Last Answer : these give unionised acid or base on reaction with added acid or alkali

Mention the Points of Difference between ‘Lithium and other Alkali Metals’

Description : Mention the Points of Difference between ‘Lithium and other Alkali Metals’

Last Answer : (i) Lithium is much harder. Its m.p. and b.p. are higher than the other alkali metals. (ii) Lithium is least reactive but the strongest reducing agent among all the alkali metals. ... and Li2O are comparatively much less soluble in water than the corresponding compounds of other alkali metals. 

Explain the stability of carbonates & bicarbonates of alkali metals .

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.  

What is the reason for the increasing stability of peroxide & superoxide of alkali metals down the group?

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.  

What are the uses of alkali metals ?

Description : What are the uses of alkali metals ? 

Last Answer : Lithium metal is used to make useful alloys, for example with lead to make white metal' bearings for motor engines, with aluminium to make aircraft parts, and with magnesium to make armour ... also used as an excellent absorbent of carbon dioxide. Caesium is used in devising photoelectric cells. 

Why do the the alkali metals give blue solution ,when treated with liq NH3?

Description : Why do the the alkali metals give blue solution ,when treated with liq NH3? 

Last Answer : The alkali metals dissolve in liquid ammonia giving deep blue solutions which are conducting in nature. The blue colour of the solution is due to the ammoniated electron which absorbs ... ammonia.) In concentrated solution, the blue colour changes to bronze colour and becomes diamagnetic.  

How does alkali metals react with halogens?

Description : How does alkali metals react with halogens?  

Last Answer : The alkali metals readily react vigorously with halogens to form ionic halides, M+X-. However, lithium halides are somewhat covalent. It is because of the high polarisation capability of lithium ion ( ... size can be easily distorted, among halides, lithium iodide is the most covalent in nature. 

Explain the reactivity of alkali metals towards water.

Description : Explain the reactivity of alkali metals towards water. 

Last Answer : The alkali metals react with water to form hydroxide and dihydrogen. It may be noted that although lithium has most negative E0 value, its reaction with water is less vigorous than ... explosively with water. They also react with proton donors such as alcohol, gaseous ammonia and alkynes.  

How does the of Hydration Enthalpy of alkaline earth metals vary & compare it with alkali metals

Description : How does the of Hydration Enthalpy of alkaline earth metals vary & compare it with alkali metals  

Last Answer : The hydration enthalpies of alkaline earth metal ions decrease with increase in ionic size down the group. Be2+> Mg2+ > Ca2+ > Sr2+ > Ba2+ The hydration enthalpies of alkaline earth metal ... and CaCl2 exist as MgCl2.6H2O and CaCl2· 6H2O while NaCl and KCl do not form such hydrates.  

How does the of Ionization Enthalpy of alkaline earth metals vary in comparison to alkali metals

Description : How does the of Ionization Enthalpy of alkaline earth metals vary in comparison to alkali metals 

Last Answer : The alkaline earth metals have low ionization enthalpies due to fairly large size of the atoms. Since the atomic size increases down the group, their ionization enthalpy decreases The first ionisation ... of the alkaline earth metals are smaller than those of the corresponding alkali metals.  

How does the atomic and Ionic Radii of alkaline earth metals vary in comparison to alkali metals

Description : How does the atomic and Ionic Radii of alkaline earth metals vary in comparison to alkali metals 

Last Answer : The atomic and ionic radii of the alkaline earth metals are smaller than those of the corresponding alkali metals in the same periods. This is due to the increased nuclear charge in these elements. Within the group, the atomic and ionic radii increase with increase in atomic number.

What happens when alkali metals react with dihydrogen?

Description : What happens when alkali metals react with dihydrogen? 

Last Answer : The alkali metals react with dihydrogen at about 673K (lithium at 1073K) to form hydrides. All the alkali metal hydrides are ionic solids with high melting points. 

Give reason for the colour imparted to the flame by alkali metals

Description : Give reason for the colour imparted to the flame by alkali metals 

Last Answer : The alkali metals and their salts impart characteristic colour to an oxidizing flame. This is because the heat from the flame excites the outermost orbital electron to a higher energy level. When the ... electron comes back to the ground state, there is emission of radiation in the visible region. 

Give reason .the melting point and boiling point of alkali metals are low

Description : Give reason .the melting point and boiling point of alkali metals are low 

Last Answer : The melting and boiling points of the alkali metals are low indicating weak metallic bonding due to the presence of only a single valence electron in them. 

How the atomic and ionic radii varies in alkali metals

Description : How the atomic and ionic radii varies in alkali metals 

Last Answer : The atomic and ionic radii of alkali metals increase on moving down the group i.e., they increase in size while going from Li to Cs.

Why alkali metals are highly electro positive & they are not found in free state ?

Description : Why alkali metals are highly electro positive & they are not found in free state ?

Last Answer : The loosely held s-electron in the outermost valence shell of these elements makes them the most electropositive metals. They readily lose electron to give monovalent M+ ions. Hence they are never found in free state in nature. 

Give reason .the compounds of alkaline earth metals are less ionic than alkali metals

Description : Give reason .the compounds of alkaline earth metals are less ionic than alkali metals

Last Answer : This is due to increased nuclear charge and smaller size. 

Name the gas liberated when alkali metals react with dil acid?

Description : Name the gas liberated when alkali metals react with dil acid?  

Last Answer : The alkaline earth metals readily react with acids liberating dihydrogen gas . M + 2HCl →→MCl2 + H2

Give reason for the higher melting point and boiling point of alkali earth metals than alkali metals.

Description : Give reason for the higher melting point and boiling point of alkali earth metals than alkali metals. 

Last Answer : The melting and boiling points of these metals are higher than the corresponding alkali metals due to smaller sizes. 

How the ionization enthalpy varies in alkali metals

Description : How the ionization enthalpy varies in alkali metals 

Last Answer : Ionization enthalpy decrease down the group from Li to Cs. 

Why I group elements are called alkali metals ?

Description : Why I group elements are called alkali metals ? 

Last Answer : These are called so because they form hydroxides on reaction with water which are strongly alkaline in nature.