Websockets help

I am trying to understand how the json is structured for websockets. The websocket api documents have a few snippets and they are helpful.
After a successful connection and authentication, I can turn a thermostat on with

{
  "id": 24,
  "type": "call_service",
  "domain": "climate",
  "service": "turn_on",
  "service_data": {
   "entity_id": "climate.thermostat"
  }
}

But the following fails to change the temperature of the thermostat.

{
	"id": "25",
	"domain": "climate",
	"type": "call_service",
	"service": "set_temperature",
	"service_data": {
		"entity_id ": "climate.thermostat",
		"temperature": "72"
	}
}

The above returns a successful message
{"id": 25, "type": "result", "success": true, "result": null}
but the thermostat is not changed.
Either the json is not formatted for how HA expects it or there is an issue with HA which is unlikely. Can someone please help me understand what I am missing.

this extra space after thermostat is intentional? or a error?

it is an error. I had edited the json prior to posting this. I will fix the post.