HomerJS said:no mass heal range is 25feet +5 feet every 2 levels.
If used against undead creatures (requires a successful touch attack), mass heal reduces them to 1d4 hp.
AuraSeer said:A spell that requires touch is not necessarily limited to one target. Look at chill touch or water breathing, both of which are multiple-target touch spells.
Also, note that a "touch attack" does not imply that physical contact is necessary. (If that were the case, the spell would have a range of Touch.) A ranged spell that uses a touch attack simply makes a ranged touch attack-- like a ray or an acid arrow.
From the SRD
Touch Attack
Touch attacks come in two types: melee touch attacks and ranged touch attacks. A character can score critical hits with either type of attack. A character's opponent's AC against a touch attack does not include any armor bonus, shield bonus, or natural armor bonus. The target's size modifier, Dexterity modifier, and deflection bonus (if any) all apply normally.
From the SRD
Touch Attack
Touch Spells and Holding the Charge: If the character doesn't discharge a touch spell on the round the character casts the spell, the character can hold the discharge of the spell (hold the charge) indefinitely.
The character can make touch attacks round after round. The character can touch one friend (or the character can touch his or her self) as a standard action or up to six friends as a full-round action. If the character touches anything with the character's hand while holding a charge, the spell discharges. If the character casts another spell, the touch spell dissipates.