Coat the chicken pieces with mixture of flour and salt. In a skillet, brown chicken on both sides in hot oil. Transfer the chicken pices to the crock pot. Blend the thawed lemonade concentrate, the 1/2 cup water, brown sugar, catsup, and vinegar; pour over chicken. Cover and cook on high heat setting until tender, 3 to 3 1/2 hours. Remove the chicken to platter; keep warm.Skim fat from the pan juices. Measure juices; add water if necessary, to make 1 1/4 cups liquid. Place the liquid into a sauce pan. Blend 1 T of cold water with the cornstarch. Stir into the pan juices. Cook and stir till thickened and bubbly. Remove from heat. Pass the sauce with chicken; serve over rice.