Since the arp request wants to know the Mac address of an ip address which belongs to any one device what's the purpose of sending a broadcast Anyway even though we know only that ip address device will respond? Can't it unicast to the receiver ip directly?
Chicken meet Egg
Ethernet can't "send something to an IP address", it can only send something to a MAC address. The whole point of ARP is to convert the IP address of the next hop (which may or may not be the destination) into a MAC address so we can send the packet.