Which one of the following alkali metals give hydrated salts?

1

(a)

Li

(b)

Na

(c)

K

(d)

Cs

The reducing property of alkali metals follows the order

1

(a)

Na < K < Rb < Cs < Li

(b)

K < Na < Rb < Cs < Li

(c)

Li < Cs < Rb < K < Na

(d)

Rb < Cs < K < Na < Li

Lithium shows a diagonal relationship with

1

(a)

sodium

(b)

silicon

(c)

nitrogen

(d)

magnesium

The oxide of which of the following metals is amphoteric?

1

(a)

Pb

(b)

Mg

(c)

Ca

(d)

Al

Hydrides as well as halides of alkaline earth metals tend to polymerize

1

(a)

Sr

(b)

Ca

(c)

Be

(d)

Mg

Lithium is the only alkali metal that forms nitride directly on reaction with air. Explain.

1

(a)

Li⁺ ion being small in size can easily stablize small nitride ion N^3-,however other alkali metal ions because of their larger size cannot stablise smaller nitride ion.Thus,only lithium forms nitride.

Which colours are imparted to flame when the following elements are introduced in the flame one by one?
Calcium-Crimson red

1

(a)

Calcium-Crimson red

Beryllium and magnesium do not give colour to flame whereas other alkaline earth metals do so. Why?

1

(a)

Be and mg-atoms, due to their small size and high effective nuclear charge, bind their electrons more strongly. Therefore, they require high excitation energy and are not excited by Bunsen flame. While other alkaline earth metals impart a characteristic colour to the flame, due to easy excitation of electrons to higher energy levels.

What is epsom salt? What is the action of heat on it?

1

(a)

MgSO₄ . 7 H₂O;
\(Mg{ SO }_{ 4 }.7{ H }_{ 2 }O\xrightarrow [ 423K ]{ -6{ H }_{ 2 }o } Mg{ SO }_{ 4 }.{ H }_{ 2 }O\)
\(\\ \xrightarrow [ 573k ]{ -{ H }_{ 2 }O } Mg{ SO }_{ 4 }\xrightarrow [ Heat ]{ . } MgO+S{ O }_{ 3 }\)

Name the three forms of calcium carbonate

1

(a)

Limestone, chalk, marble.

Identify A, B, C, and  D and give their chemical formulae.
B + NaCl\( \rightarrow\) C + NH₄Cl

2

(a)

How would you explain BaO is soluble but BaSO₄ is insoluble in water.

2

(a)

Which electrolyte is used to obtain sodium in Castner's process?

2

(a)

What do you mean by diagonal relationship in periodic table?

2

(a)

What happens when sodium metal is heated in free supply of air ?

4

(a)

A certain salt X gives the results  Borax swells up to a glassy mass on strong heating.
Its aqueous solution alkaline to litmus.

4

(a)

Explain Lithium does not form alums

4

(a)

Dr.Sharma , cardiologist suggested his patienta to take more potassium ions for healthy heart. potassium ions are the most abundant cations within cell fluids, where they activate many enzymes, participate in the oxidation of glucose to pro duse ATP While sodiun ions are responsible for the transmission for nerve signals. What are the sources of potassium ?

4

(a)

Starting with sodium chloride how would you proceed to prepare? Sodium peroxide.

4

(a)

Compare four properties of alkali metals and alkaline earth metals

5

(a)

State Li is the best reducing agent in aqueous solution Why?

5

(a)