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

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

1 Answer

Answer :

Li
by

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What are the uses of alkali metals ?

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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?

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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. 

Give the names of four alkali metals:

Description : Give the names of four alkali metals: 

Last Answer : ANSWER: LITHIUM, SODIUM, POTASSIUM, RUBIDIUM, CESIUM, AND FRANCIUM  

Name any four alkali metals.

Description : Name any four alkali metals.

Last Answer : ANSWER: LITHIUM, SODIUM, POTASSIUM, RUBIDIUM, CESIUM, AND FRANCIUM

The elements in group 1A of the periodic table are called: w) halogens x) alkaline earths y) alkali metals z) rare earths

Description : The elements in group 1A of the periodic table are called: w) halogens x) alkaline earths y) alkali metals z) rare earths

Last Answer : ANSWER: Y -- ALKALI METALS

Which of the following alkali metals has highest specific heat? (1) Caesium (2) Rubidium (3) Potassium (4) Lithium

Description : Which of the following alkali metals has highest specific heat? (1) Caesium (2) Rubidium (3) Potassium (4) Lithium

Last Answer : Lithium