实验测定：

①称取一定质量的样品加入稀盐酸中充分溶解，将所得溶液转移至容器瓶并配制成l00.00mL 溶液A．

②量取25.00mL溶液A，加入盐酸酸化的BaCl₂溶液至沉淀完全，过滤、洗涤、干燥至恒重，得到白色固体9.32g．

③量取25.00mL溶液A，加入足量KI，用2.000mol•L^﹣1Na₂S₂O₃溶液进行滴定（已知反应为I₂+2Na₂S₂O₃═2NaI+Na₂S₄O₆，消耗30.00mL Na₂S₂O₃溶液至终点．

    The giraffe is the tallest modern land animal. It can be over 5. 5 meters tall. Its neck alone may be 1. 9 meters long. Yet the giraffe has only seven bones in its neck, the same number as in the humans'. Even a small bird has many more bones in its neck than a tall giraffe. Each bone in a giraffe's neck is very long, while the bones in a human's neck are short. That makes the difference. A female giraffe gives birth to one baby at a time. The baby, called a calf, is about 1. 9 meters tall at birth. By the age of eight it is full-grown. The giraffe eats mostly leaves. Because it has a long neck, it can reach the high leaves on the trees.

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物质KCl的溶解度曲线如图所示：

实验过程中，向100g水中不断加入固体KCl或改变温度，得到相应的溶液①～④．