中学生网络课堂本课配套习题挑战模式1/5
单选题
难度系数：
1.
“凯式定氮法”是通过测奶品中含氮量（氮元素的质量分数）来折算奶品中蛋白质含量的一种方法。为了提高氮的含量，不法分子将三聚氰胺（化学是为C3H6N6）添加进奶品中，冒充蛋白质，使许多婴幼儿长期服用后产生结石，严重影响婴幼儿的健康。如果不法分子向1000g牛奶中添加2.52g三聚氰胺，能够冒充蛋白质的质量为____（已知蛋白质中所含氮元素的质量分数约为16%）
| A: 2.52g |
| B: 4.44g |
| C: 10.5g |
| D: 12.32g |
一次做对，真牛！
+5奖励规则>
- 提示1：PHA+Mi41MmfkuInogZrmsLDog7rkuK1O5YWD57Sg55qE6LSo6YeP562J5LqO6IO95aSf5YaS5YWF55qE6JuL55m96LSo55qE6LSo6YeP5LitTuWFg+e0oOeahOi0qOmHjzwvcD4=
- 提示2：PHA+6K6+6IO95aSf5YaS5YWF6JuL55m96LSo55qE6LSo6YeP5Li6eO+8jOWImTwvcD4=
- 提示3：PHA+PGltZyBoZWlnaHQ9IjczIiB3aWR0aD0iMjkzIiBkYXRhLWNrZS1zYXZlZC1zcmM9Imh0dHBzOi8vcDEucWluZ2d1by5jb20vRzEvTTAwLzM0LzBBL3JCQUNFMU1TODFPVGkyMENBQUFQc2tLY2VNVTQ1NS5wbmciIHNyYz0iaHR0cHM6Ly9wMS5xaW5nZ3VvLmNvbS9HMS9NMDAvMzQvMEEvckJBQ0UxTVM4MU9UaTIwQ0FBQVBza0tjZU1VNDU1LnBuZyI+PC9wPg==
- 答案：Qw==
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
本课配套习题挑战模式2/5
单选题
难度系数：
2.
“凯式定氮法”是通过测奶品中含氮量（氮元素的质量分数）来折算奶品中蛋白质含量的一种方法。为了提高氮的含量，不法分子将三聚氰胺（化学是为C3H6N6）添加进奶品中，冒充蛋白质，使许多婴幼儿长期服用后产生结石，严重影响婴幼儿的健康。如果不法分子向1000g牛奶中添加2.52g三聚氰胺，能够冒充蛋白质的质量为____
（已知蛋白质中所含氮元素的质量分数约为16%）
| A: 2.52g |
| B: 4.44g |
| C: 10.5g |
| D: 12.32g |
一次做对，真牛！
+5奖励规则>
- 提示1：PHA+Mi41MmfkuInogZrmsLDog7rkuK1O5YWD57Sg55qE6LSo6YeP562J5LqO6IO95aSf5YaS5YWF55qE6JuL55m96LSo55qE6LSo6YeP5LitTuWFg+e0oOeahOi0qOmHjzwvcD4=
- 提示2：PHA+6K6+6IO95aSf5YaS5YWF6JuL55m96LSo55qE6LSo6YeP5Li6eO+8jOWImTwvcD4=
- 提示3：PHA+PGltZyBoZWlnaHQ9IjczIiB3aWR0aD0iMjkzIiBkYXRhLWNrZS1zYXZlZC1zcmM9Imh0dHBzOi8vcDEucWluZ2d1by5jb20vRzEvTTAwLzJFLzg5L3JCQUNFMU1Sb1RYUTZCZ2VBQUFQc2kwdzcxODE2Mi5wbmciIHNyYz0iaHR0cHM6Ly9wMS5xaW5nZ3VvLmNvbS9HMS9NMDAvMkUvODkvckJBQ0UxTVJvVFhRNkJnZUFBQVBzaTB3NzE4MTYyLnBuZyI+PC9wPg==
- 答案：Qw==
PGRpdj7op6PvvJrnlLHpopjmhI/lj6/nn6XvvIwyLjUyZ+S4ieiBmuawsOiDuuS4rU7lhYPntKDnmoTotKjph4/nrYnkuo7og73lpJ/lhpLlhYXnmoTom4vnmb3otKjnmoTotKjph4/kuK1O5YWD57Sg55qE6LSo6YeP77yMPGJyPuiuvuiDveWkn+WGkuWFheibi+eZvei0qOeahOi0qOmHj+S4unjvvIzliJk8L2Rpdj48ZGl2PjxpbWcgaGVpZ2h0PSI2OCIgd2lkdGg9IjI5OCIgZGF0YS1ja2Utc2F2ZWQtc3JjPSJodHRwczovL3AyLnFpbmdndW8uY29tL0cxL00wMC8yRS84OS9yQkFDRTFNUm9UV3hULWN6QUFBRmxXcE45Nm8wNjAucG5nIiBzcmM9Imh0dHBzOi8vcDIucWluZ2d1by5jb20vRzEvTTAwLzJFLzg5L3JCQUNFMU1Sb1RXeFQtY3pBQUFGbFdwTjk2bzA2MC5wbmciPjwvZGl2Pg==
本课配套习题挑战模式3/5
单选题
难度系数：
3.
某粗盐样品中含有可溶性的氯化镁、氯化钙杂质和不溶性的泥沙。常温下，将140g该粗盐样品溶解于水中，过滤得到不足3g泥沙和1000g溶液。取出500g溶液进行测定，其中含有镁元素1.2g，钙元素2g，氯元素42.6g。则原粗盐中氯化钠的质量分数约为_____
| A: 83.6% |
| B: 86.3% |
| C: 88.1% |
| D: 91.6% |
一次做对，真牛！
+5奖励规则>
- 提示1：PHA+5Yip55So5YyW5ZCI54mp55qE6LSo6YePPeWFg+e0oOi0qOmHj8O35YyW5ZCI54mp5Lit6K+l5YWD57Sg55qE6LSo6YeP5YiG5pWw77yM55SxTWflhYPntKDjgIFDYeWFg+e0oOeahOi0qOmHj+iuoeeul+WHuk1nQ2w8c3ViPjI8L3N1Yj7lkoxDYUNsPHN1Yj4yPC9zdWI+55qE6LSo6YeP77yb5YaN5Yip55SoTWdDbDxzdWI+Mjwvc3ViPuOAgUNhQ2w8c3ViPjI8L3N1Yj7kuKTljJblkIjniannmoTotKjph4/orqHnrpflhbbkuK1DbOWFg+e0oOeahOi0qOmHj++8mzxicj48L3A+
- 提示2：PHA+54S25ZCO5Yip55So5bey5rWL5a6a5Ye655qEQ2zlhYPntKDnmoTmgLvotKjph4/lh4/ljrtNZ0NsPHN1Yj4yPC9zdWI+44CBQ2FDbDxzdWI+Mjwvc3ViPuS4rUNs5YWD57Sg6LSo6YeP5Y+v5rGC5b6XTmFDbOS4rUNs5YWD57Sg6LSo6YeP77yM5YaN5Yip55So5YWD57Sg6LSo6YeP5LiO5YyW5ZCI54mp6LSo6YeP55qE5YWz57O75byP77yM6K6h566X5Ye6TmFDbOeahOi0qOmHj++8mzxicj48L3A+
- 提示3：PHA+5pyA5ZCO77yM5Yip55So5omA6K6h566XTmFDbOi0qOmHj+eahDLlgI3kuI4xNDBn57KX55uQ55qE5q+U77yM5rGC5b6X57KX55uQ5LitTmFDbOeahOi0qOmHj+WIhuaVsC48L3A+
- 答案：QQ==
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
本课配套习题挑战模式4/5
单选题
难度系数：
4.
在CO、HCOOH、OHC-COOH的混合物中，已知氢元素的质量分数为y，则碳元素的质量分数为_____
| A:
|
| B:
|
| C:
|
| D:
|
一次做对，真牛！
+5奖励规则>
- 提示1：PHA+5aaC5p6c5oqKSENPT0jnmoTnu4TmiJDooajnpLrkuLpDT+KAokg8c3ViPjI8L3N1Yj5P44CBT0hDLUNPT0jnmoTnu4TmiJDooajnpLrkuLoyQ0/igKJIPHN1Yj4yPC9zdWI+T++8jOmCo+S5iOaVtOS4qua3t+WQiOawlOS9k+WImeeUsUNP5ZKMSDxzdWI+Mjwvc3ViPk/nu4TmiJDvvJs8L3A+
- 提示2：PHA+5qC55o2u5re35ZCI54mp5Lit5rCi5YWD57Sg55qE6LSo6YeP5YiG5pWw5Y+v6K6h566X5Ye65re35ZCI54mp5Lit5rC055qE6LSo6YeP5Y+KQ0/nmoTotKjph4/liIbmlbDvvIznlLFDT+eahOi0qOmHj+WIhuaVsOWPr+i/m+S4gOatpeiuoeeul+WHukPlhYPntKDlnKjmt7flkIjnianotKjkuK3nmoTotKjph4/liIbmlbAuPC9wPg==
- 答案：QQ==
PGRpdj48aW1nIGhlaWdodD0iMTAyIiB3aWR0aD0iNTUzIiBkYXRhLWNrZS1zYXZlZC1zcmM9Imh0dHBzOi8vcDEucWluZ2d1by5jb20vRzEvTTAwLzBCLzk3L3JCQUNGRk1ScENlVFkzSUtBQUFxcXpWRFhDUTI4LmpwZWciIHNyYz0iaHR0cHM6Ly9wMS5xaW5nZ3VvLmNvbS9HMS9NMDAvMEIvOTcvckJBQ0ZGTVJwQ2VUWTNJS0FBQXFxelZEWENRMjguanBlZyI+PC9kaXY+
本课配套习题挑战模式5/5
单选题
难度系数：
5.
某技术员在分析醋酸溶液中溶质的含量时，测得溶液中氧元素的质量分数为80%，则该醋酸溶液中，醋酸的质量分数为_____
| A: 5% |
| B: 14% |
| C: 20% |
| D: 25% |
一次做对，真牛！
+5奖励规则>
- 提示1：PHA+55Sx5LqO6aKY55uu5Lit5rKh57uZ5Ye65piO56Gu55qE5pWw5YC877yM5omA6Kej562U5pe25Y+v5Lul6K6+5Ye65rq25ray5Lit5rC055qE6LSo6YeP5ZKM5rq26LSo55qE6LSo6YeP77yM5qC55o2u5rCn5YWD57Sg55qE6LSo6YeP5YiG5pWw5p2l5YiX5byP6K6h566X5Y+v5b6X5Ye65rq25YmC5ZKM5rq26LSo6LSo6YeP55qE5YWz57O777yM54S25ZCO6K6h566X6K+l5rq25ray5Lit5rq26LSo55qE6LSo6YeP5YiG5pWwLjwvcD4=
- 答案：RA==
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
