Question
Question: Thermal stability of hydrides of alkali metals decreases in the order....
Thermal stability of hydrides of alkali metals decreases in the order.
A
LiH > NaH > KH > RbH > CsH
B
CsH > RbH > KH > NaH > LiH
C
LiH = NaH > KH = RbH > CsH
D
LiH > NaH > CsH > RbH > KH
Answer
LiH > NaH > KH > RbH > CsH
Explanation
Solution
: Since electropositive character increases from Li to Cs, reactivity of hydrides increases from Li to Cs while thermal stability decreases from Li to Cs.