Question

Rate of evaporation decreases when common salt is added to water. Why ?​

Answer 1

Explanation:

◤ᴡʜʏ? ᴡʜᴇɴ ᴀ ɴᴏɴ-ᴠᴏʟᴀᴛɪʟᴇ ꜱᴏʟᴜᴛᴇ ᴛʜᴀᴛ ɪꜱ ꜱᴀʟᴛ ɪꜱ ᴀᴅᴅᴇᴅ ᴛᴏ ᴀ ꜱᴏʟᴠᴇɴᴛ ᴛʜᴀᴛ ᴡᴀᴛᴇʀ, ᴛʜᴇ ᴠᴀᴘᴏᴜʀ ᴘʀᴇꜱꜱᴜʀᴇ ᴏꜰ ᴛʜᴇ ʀᴇꜱᴜʟᴛɪɴɢ ꜱᴏʟᴜᴛɪᴏɴ (ꜱᴀʟᴛ ꜱᴏʟᴜᴛɪᴏɴ) ɪꜱ ʟᴇꜱꜱ ᴛʜᴀɴ ᴛʜᴇ ᴠᴀᴘᴏᴜʀ ᴘʀᴇꜱꜱᴜʀᴇ ᴀʙᴏᴠᴇ ᴛʜᴇ ᴘᴜʀᴇ ꜱᴏʟᴠᴇɴᴛ (ᴡᴀᴛᴇʀ). ᴛʜᴜꜱ ʀᴀᴛᴇ ᴏꜰ ᴇᴠᴀᴘᴏʀᴀᴛɪᴏɴ ᴅᴇᴄʀᴇᴀꜱᴇꜱ.◢

Answer 2

Explanation:

why? When a non-volatile solute that is salt is added to a solvent that water, the vapour pressure of the resulting solution (salt solution) is less than the vapour pressure above the pure solvent (water). Thus rate of evaporation decreases