Question
Discuss chemical properties of lanthanoids.
✓
Answer
$\rightarrow$ In their chemical behaviour, in general, the earlier members of the series are quite reactive similar to calcium but, with increasing atomic number, they behave more like aluminium.
$\rightarrow$ The value of $E ^0$ of half reaction
$\operatorname{Ln}_{( aq )}^{3+}+3 e ^{-} \longrightarrow Ln ( s ) \text { range from }-2.21$
to $2.4 V$ except for $Eu$ that has $-2.0 V .$
$\rightarrow$ Lanthanoids heated with carbon forms carbides $Ln_3C, Ln_2C_3$ and $LnC_2$
$\rightarrow$ Lanthanoids form trihalides $LnX_3$ with halogen and liberates hydrogen gas when treated with dilute acids.
$\rightarrow$ These metals combine with oxygen to form oxides of type $Ln_2O_3$
$\rightarrow$ Oxides are basic in nature and when dissloved in water they form hydroxide $Ln(OH)_3.$
$\rightarrow$ The value of $E ^0$ of half reaction
$\operatorname{Ln}_{( aq )}^{3+}+3 e ^{-} \longrightarrow Ln ( s ) \text { range from }-2.21$
to $2.4 V$ except for $Eu$ that has $-2.0 V .$
$\rightarrow$ Lanthanoids heated with carbon forms carbides $Ln_3C, Ln_2C_3$ and $LnC_2$
$\rightarrow$ Lanthanoids form trihalides $LnX_3$ with halogen and liberates hydrogen gas when treated with dilute acids.
$\rightarrow$ These metals combine with oxygen to form oxides of type $Ln_2O_3$
$\rightarrow$ Oxides are basic in nature and when dissloved in water they form hydroxide $Ln(OH)_3.$
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