Ions of an element of group 1 participate in the transmission of nerve signalsand transport of sugars and aminoacids into cells. This element imparts yellowcolour to the flame in flame test and forms an oxide and a peroxide withoxygen. Identify the element and write chemical reaction to show the formationof its peroxide. Why does the element impart colour to the flame?
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An element of group 2 forms covalent oxide which is amphoteric in natureand dissolves in water to give an amphoteric hydroxide. Identify the elementand write chemical reactions of the hydroxide of the element with an alkaliand an acid.
Lithium hydride can be used to prepare other useful hydrides. Berylliumhydride is one of them. Suggest a route for the preparation of beryllium hydridestarting from lithium hydride. Write chemical equations involved in the process.
When water is added to compound (A) of calcium, solution of compound (B)is formed. When carbon dioxide is passed into the solution, it turns milkydue to the formation of compound (C). If excess of carbon dioxide is passedinto the solution milkiness disappears due to the formation of compound(D). Identify the compounds A, B, C and D. Explain why the milkinessdisappears in the last step.
Assertion (A): Beryllium carbonate is kept in the atmosphere of carbondioxide.Reason (R) : Beryllium carbonate is unstable and decomposes to giveberyllium oxide and carbon dioxide.(i) Both A and R are correct and R is the correct explanation of A.(ii) Both A and R are correct but R is not the correct explanation of A.(iii) Both A and R are not correct.(iv) A is not correct but R is correct.
Match the elements given in Column I with the colour they impart to theflame given in Column II.Column I Column II(i) Cs (a) Apple green(ii) Na (b) Violet(iii) K (c) Brick red(iv) Ca (d) Yellow(v) Sr (e) Crimson red(vi) Ba (f) Blue
Show with an example that Ca O is a basic oxide?
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What happens when CaCO3 is subjected to heat?
What is milk of lime?
Mention the natural sources of calcium carbonate.
What is the formulae of caustic potash?
Anhydrous calcium sulphate can not be used as plaster of Paris. Give reason.
What happens when gypsum is heated to 390K?
What is quick lime? What happens when we add water to it?
Give two uses of(i) caustic soda(ii) quick lime
Mention the main compounds which constitute Portland cement.
Beryllium is reducing in nature. Why?
Give the reaction of magnesium with air?
Why beryllium is not attacked by an acid easily?
Why does the solubility of alkaline earth metal hydroxides in water increasedown the group?
Why sulphates of Mg and Be soluble in water?
Name the metal amongst alkaline earth metals whose salt do not impartcolour to a non – luminous flame.
Why is beryllium carbonate unusually unstable thermally as compared to theother carbonates of this group?
Why is Calcium preferred over sodium to remove last traces of moisture fromalcohol?
Why does beryllium show similarities with Al?
What is the nature of oxide formed by Be?
The alkaline earth metals are called s – block elements. Give reasons.
Which member of the alkaline earth metals family has:(i) least reactivity (ii) lowest density (iii) highest boiling point(iv) maximum reduction potential
The melting and boiling points of alkaline metals are higher than alkali metals.Give reason.
Compounds of alkaline earth metals are more extensively hydrated than thoseof alkali metals. Give reason.
Name the metal amongst alkaline earth metals whose salt do not impart colourto a non-luminous flame.
State one reason for alkaline earth metals in general having a greater tendencyto form complexes than alkali metals.
The second ionization enthalpy of calcium is more than the first. How is that
calcium forms CaCl2 and not CaCl give reasons.
Why do alkaline earth metals have low ionization enthalpy?
The atomic radii of alkaline earth metals are smaller than those of thecorresponding alkali metals. Explain why?
Name the elements present in Group 2
Solution of Na2 CO3 is alkaline. Give reason.
Give two uses of sodium carbonate?
What is the formula of soda ash?
Which compound of sodium is used:(i) as a component of baking powder.(ii) for softening hard water.
What is the difference between baking soda and baking powder?
Why does table salt get wet in rainy season?
Why is sodium hydrogen carbonate known as baking powder?
What is sodium amalgam?
Give the important uses of sodium carbonate.
How is sodium carbonate prepared?
Why metals like potassium and sodium can not be extracted by reduction oftheir oxides by carbon?
Lithium shows similarities with magnesium in its chemical behavior. What isthe cause of these similarities?
Write a reaction to show that bigger cat ions stabilize bigger anions.
Name the alkali metals that form super oxides when heated in excess of air.
Why are lithium compounds soluble in organic solvents?
Name the anomalous properties of lithium
Why are peroxides and super oxides stable in comparison to other oxides?
Why alkali metal hydroxides are make the strongest bases?
Name the lightest metal.
Why is potassium lighter than sodium?
What type of oxide is made by sodium?
Why do alkali metals and salts impart color to an oxidizing flame?
What makes lithium show properties different from rest of the alkali metals?
Why are lithium halides covalent in nature?
Why is lithium kept under kerosene oil?
What do you mean by diagonal relationship in the periodic table?
Why are melting and boiling points of alkali metals low?
Why is lithium salts mostly hydrated?
Why is Group I elements known as the most electropositive element?
Which one of the alkaline earth metal carbonates is thermally the most stable?
(a) MgCO3 (b) CaCO3 (c) SrCO3 (d) BaCO3
Which one of the following alkali metals gives hydrated salts?
(a) Li (b) Na (c) K (d) Cs
Which of the alkali metal is having least melting point?
(a) Na (b) K (c) Rb (d) Cs
How would you explain the following observations?
(i) BeO is almost insoluble but BeSO4 in soluble in water,
(ii) BaO is soluble but BaSO4 is insoluble in water,
(iii) LiI is more soluble than KI in ethanol.
Write balanced equations for reactions between
(a) Na2O2and water
(b) KO2 and water
(c) Na2O and CO2
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 ?
Comment on each of the following observations:
(a) The mobilities of the alkali metal ions in aqueous solution are Li+< Na+< K+ < Rb+ < Cs+
(b) Lithium is the only alkali metal to form a nitride directly.
(c)
(where M = Ca, Sr or Ba) is nearly constant.
What happens when
(i) sodium metal is dropped in water ?
(ii) sodium metal is heated in free supply of air ?
(iii) sodium peroxide dissolves in water ?
Explain the significance of sodium, potassium, magnesium and calcium inbiological fluids.
Why is LiF almost insoluble in water whereas LiCl soluble not only in water but also in acetone?
Why are lithium salts commonly hydrated and those of the other alkali metal ions usually anhydrous?
Describe the importance of the following: (i) limestone (ii) cement (iii) plaster of paris.
The hydroxides and carbonates of sodium and potassium are easily soluble in water while the corresponding salts of magnesium and calcium are sparingly soluble in water. Explain.
Draw the structure of (i) BeCl2 (vapour) (ii) BeCl2 (solid).
Describe two important uses of each of the following: (i) caustic soda (ii) sodium carbonate (iii) quicklime.
What happens when (i) magnesium is burnt in air (ii) quick lime is heated with silica (iii) chlorine reacts with slaked lime (iv) calcium nitrate is heated ?
Starting with sodium chloride how would you proceed to prepare (i) sodium metal (ii) sodium hydroxide (iii) sodium peroxide (iv) sodium carbonate?
Compare the solubility and thermal stability of the following compounds of the alkali metals with those of the alkaline earth metals. (a) Nitrates (b) Carbonates (c) Sulphates.
Find the oxidation state of sodium in Na2O2.
Why are alkali metals not found in nature?
Discuss the general characteristics and gradation in properties of alkaline earth metals.
What are the common physical and chemical features of alkali metals?
Why is Li2CO3 decomposed at a lower temperature whereas Na2CO3 at higher temperature?
Potassium carbonate cannot be prepared by Solvay process. Why?
Discuss the various reactions that occur in the Solvay process.
Beryllium and magnesium do not give colour to flame whereas other alkaline earth metals do so. Why?
When an alkali metal dissolves in liquid ammonia the solution can acquire different colours. Explain the reasons for this type of colour change.
Why are potassium and cesium, rather than lithium used in photoelectric cells?
Explain why alkali and alkaline earth metals cannot be obtained by chemical reduction methods?
In what ways lithium shows similarities to magnesium in its chemical behaviour?
Compare the alkali metals and alkaline earth metals with respect to (i) ionization enthalpy (ii) basicity of oxides and (iii) solubility of hydroxides.
Explain why is sodium less reactive than potassium?