题干

下表是氯化钠和硝酸钾在不同温度下的溶解度。(假设硝酸钾与氯化钠同时溶解在水中各自的溶解度不变,实验过程中水分损失忽略不计)。
温度(℃)
0
20
40
60
80
100
溶解度(g/100g水)
KNO3
13.3
31.6
64.0
110.0
169.0
246.0
NaCl
35.7
36.0
36.6
37.3
38.4
39.8
①由表可知,20℃时,氯化钠的溶解度是____。影响硝酸钾溶解度的因素是____。 
②在80℃的100g水中溶解NaCl和KNO3,进行以下实验:
Ⅰ.操作1的名称是____
Ⅱ.溶液a冷却至b的过程中出现的现象是____。溶液d中所含的溶质是____
Ⅲ.对整个实验过程分析正确的是____
A.无法判断a、d溶液中氯化钠溶液的状态            B.固体c是纯净物
C.溶液a中硝酸钾的质量分数为 169269
             D.硝酸钾溶液始终处于饱和状态
上一题 下一题 0.0难度 选择题 更新时间:2019-12-24 04:45:36

答案(点此获取答案解析)

36.0g/100g水,温度,过滤,有固体析出或溶液变浑浊,KNO3、NaCl,BD

同类题3

根据短文理解,选择正确答案。

    Hannah Levine decided she wanted to give hugs to all of the children and families in need at local hospitals.

    Because she couldn't give them one by one, Levine, then a sixth-grader, decided she would use her talents(才能) to do the next best thing. She began to knit(编织) hats, scarves, and blankets for families staying at the Ronald McDonald House at Stanford. Her creations also went to Bundle of Joy, a program that provides newborn baby items for families in need, and to Knitting Pals by the Bay, a local organization that provides hand-knitted caps to cancer patients.

    “I love to knit, and I thought it would be a great idea to make all these handmade items for kids and adults who need them. It would be like a hug for them,” Levine explained.

    Levine started the project about a year ago. “I think it's just really fun to do, and it keeps me busy,” said Levine, now 13.

    Once she got started, Levine realized that her project could be much bigger than the goods she was able to produce with just her own hands. So she sent emails to her school and communities(社区), asking for knitted donations(捐赠物) to the project she named “Hannah's Warm Hugs”. She also posted advertisements at Starbucks and other locations in her area. The warm goods began to gush in.

    “It was amazing; more strangers than people she knew started dropping donations at our door,” said Levine's mother, Laura Levine. “We ended up with this huge box of items she was donating.”

    The knitted items numbered in the hundreds. Levine made her first round of donations around Hanukkah (an eight-day Jewish holiday in November or December) and later received thank-you letters from the organizations. Levine is still knitting, and she said the project will continue.

    “It has turned into a bigger thing than she had thought,” her mom said. “It made her feel pretty good; it made us feel pretty good.”