配套习题- 中考化学计算——技巧篇之守恒法（1） -【青果学院】

1/5单选题

难度：

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

正确答案：Qw==

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

2/5单选题

难度：

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

正确答案：Qw==

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

3/5单选题

难度：

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%

正确答案：QQ==

PGRpdj48aW1nIHNyYz0iaHR0cHM6Ly9wMS5xaW5nZ3VvLmNvbS9HMS9NMDAvMEIvOTcvckJBQ0ZGTVJwQWp6azhVWkFBQWxLaWhYLW9VNzU3LnBuZyIgZGF0YS1ja2Utc2F2ZWQtc3JjPSJodHRwczovL3AxLnFpbmdndW8uY29tL0cxL00wMC8wQi85Ny9yQkFDRkZNUnBBanprOFVaQUFBbEtpaFgtb1U3NTcucG5nIiBoZWlnaHQ9IjIzMiIgd2lkdGg9IjM2NSI+PC9kaXY+PGRpdj7miYDku6Xljp/nspfnm5DkuK3msK/ljJbpkqDnmoTotKjph4/liIbmlbDkuLo8aW1nIHNyYz0iaHR0cHM6Ly9wMS5xaW5nZ3VvLmNvbS9HMS9NMDAvMkUvOUQvckJBQ0UxTVJwQWpnNkktUEFBQUJ3WFIwSlhNOTIyLnBuZyIgZGF0YS1ja2Utc2F2ZWQtc3JjPSJodHRwczovL3AxLnFpbmdndW8uY29tL0cxL00wMC8yRS85RC9yQkFDRTFNUnBBamc2SS1QQUFBQndYUjBKWE05MjIucG5nIiBoZWlnaHQ9IjQyIiB3aWR0aD0iMjYiPsOXMTAwJT04My42JTwvZGl2Pg==

4/5单选题

难度：

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

正确答案：QQ==

PGRpdj48aW1nIGhlaWdodD0iMTAyIiB3aWR0aD0iNTUzIiBkYXRhLWNrZS1zYXZlZC1zcmM9Imh0dHBzOi8vcDEucWluZ2d1by5jb20vRzEvTTAwLzBCLzk3L3JCQUNGRk1ScENlVFkzSUtBQUFxcXpWRFhDUTI4LmpwZWciIHNyYz0iaHR0cHM6Ly9wMS5xaW5nZ3VvLmNvbS9HMS9NMDAvMEIvOTcvckJBQ0ZGTVJwQ2VUWTNJS0FBQXFxelZEWENRMjguanBlZyI+PC9kaXY+

5/5单选题

难度：

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%

正确答案：RA==

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