(1)t1℃时,甲乙两物质的溶解度曲线交于一点,故甲乙溶解度相等;故答案为:=(2)t2℃时,乙物质饱和溶液的溶质的质量分数是 80g 80g+100g ×100%=44.4%,故答案为:44.4%(3)t2℃时,乙的溶解度为80g,故把100g乙物质放入100g水中只能溶解80g,,充分搅拌后所得溶液为饱和溶液,故答案为:饱和.