Question

write a short note on hydration enthalpy in alkali metals​

Answer 1

Answer:

The hydration enthalpy is the enthalpy change when 1 mole of gaseous ions dissolve in sufficient water to give an infinitely dilute solution. Hydration enthalpies are always negative. ... Because Li+ is much smaller than the other alkali metal cations, it's hydration energy is the highest.

Answer 2

ᴀɴsᴡᴇʀ :-

☞ᴛʜᴇ ʜᴇᴀᴛ ᴇɴᴇʀɢʏ ʀᴇʟᴇᴀsᴇᴅ ᴡʜᴇɴ ɴᴇᴡ ʙᴏɴᴅs ᴀʀᴇ ᴍᴀᴅᴇ ʙᴇᴛᴡᴇᴇɴ ᴛʜᴇ ɪᴏɴs ᴀɴᴅ ᴡᴀᴛᴇʀ ᴍᴏʟᴇᴄᴜʟᴇs ɪs ᴋɴᴏᴡɴ ᴀs ᴛʜᴇ ʜʏᴅʀᴀᴛɪᴏɴ ᴇɴᴛʜᴀʟᴘʏ ᴏғ ᴛʜᴇ ɪᴏɴ.

☞ᴛʜᴇ ʜʏᴅʀᴀᴛɪᴏɴ ᴇɴᴛʜᴀʟᴘʏ ɪs ᴛʜᴇ ᴇɴᴛʜᴀʟᴘʏ ᴄʜᴀɴɢᴇ ᴡʜᴇɴ 1 ᴍᴏʟᴇ ᴏғ ɢᴀsᴇᴏᴜs ɪᴏɴs ᴅɪssᴏʟᴠᴇ ɪɴ sᴜғғɪᴄɪᴇɴᴛ ᴡᴀᴛᴇʀ ᴛᴏ ɢɪᴠᴇ ᴀɴ ɪɴғɪɴɪᴛᴇʟʏ ᴅɪʟᴜᴛᴇ sᴏʟᴜᴛɪᴏɴ. ʜʏᴅʀᴀᴛɪᴏɴ ᴇɴᴛʜᴀʟᴘɪᴇs ᴀʀᴇ ᴀʟᴡᴀʏs ɴᴇɢᴀᴛɪᴠᴇ.

☞ᴛʜᴇ sᴛᴀɴᴅᴀʀᴅ ʀᴇᴅᴜᴄᴛɪᴏɴ ᴘᴏᴛᴇɴᴛɪᴀʟs (ᴇ°) ᴏғ ᴛʜᴇ ᴀʟᴋᴀʟɪ ᴍᴇᴛᴀʟs ᴅᴏ ɴᴏᴛ ғᴏʟʟᴏᴡ ᴛʜᴇ ᴛʀᴇɴᴅ ʙᴀsᴇᴅ ᴏɴ ɪᴏɴɪᴢᴀᴛɪᴏɴ ᴇɴᴇʀɢɪᴇs. ᴜɴᴇxᴘᴇᴄᴛᴇᴅʟʏ, ʟɪᴛʜɪᴜᴍ ɪs ᴛʜᴇ sᴛʀᴏɴɢᴇsᴛ ʀᴇᴅᴜᴄᴛᴀɴᴛ, ᴀɴᴅ sᴏᴅɪᴜᴍ ɪs ᴛʜᴇ ᴡᴇᴀᴋᴇsᴛ. ʙᴇᴄᴀᴜsᴇ ʟɪ+ ɪs ᴍᴜᴄʜ sᴍᴀʟʟᴇʀ ᴛʜᴀɴ ᴛʜᴇ ᴏᴛʜᴇʀ ᴀʟᴋᴀʟɪ ᴍᴇᴛᴀʟ ᴄᴀᴛɪᴏɴs, ɪᴛ's ʜʏᴅʀᴀᴛɪᴏɴ ᴇɴᴇʀɢʏ ɪs ᴛʜᴇ ʜɪɢʜᴇsᴛ.