You have identified the promise to take turns at cleaning the kitchen and taking out the garbage as a social arrangement, enforced by peer pressure and cooperation.
Unlike the promise to pay rent, the promise made by each of the persons living in the shared house to help with keeping the house clean is clearly only a social or domestic arrangement. Such promises are not enforceable in the courts: they depend for enforcement on the need for cooperation within the group and the willingness of the group to exert pressure on an individual who breaks their promise.