某品牌洁厕灵的成分是硫酸与盐酸的混合溶液，某课外活动小组想测定该品牌洁厕灵溶液中HCl的质量．取20g该品牌的洁厕灵溶液于烧杯中，不断滴加溶质质量分数为17.1%的氢氧化钡溶液，反应过程中烧杯中产生沉淀质量和烧杯中溶液pH变化的部分数据如表所示：（已知BaCl₂溶液的pH=7）

求：

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What Will Be Done-With All This Denim?

    All the denim (牛仔布) will be donated to Cotton From Blue to Green, which recycles jeans into UltraTouch Natural Cotton Fiber Insulation (纤维隔热材料), which is used to help build houses in places that have been damaged by hurricanes and other natural disasters. Your jeans will help keep clothes out of landfills (垃圾场), and build houses for families to live in! UltraTouch is made of 85% recycled fibers and is an environmentally safe, natural cotton fiber insulation.

It's a Fact

    It takes about 500 pairs of jeans to recycle enough denim to insulate one average-size U.S house.

Here's How You Can Get Involved!

1). Get a parent's permission and select as many denim jeans as you like. (Any denim clothing is OK)

2). The denim must be used.

3). The denim can be any brand.

4). The denim can be any color or size but must have been worn by a human (no doll clothes!).

5). Jeans must be received by June 30, 2017.

    By donating denim, you can give it a “new life” by converting it into UltraTouch Natural Cotton Fiber Insulation. Click here for more information about the denim drive.

    UltraTouch is composed of 85% recycled fibers and is an environmentally safe, non- itch natural cotton fiber insulation. For more information about UltraTouch, click here.