1.单选题- (共9题)
①碱的水溶液通常呈碱性,所以碱性溶液一定是碱的溶液
②化合物是由不同种元素组成的纯净物,所以由不同种元素组成的纯净物一定是化合物
③分子是构成物质的微粒,所以物质一定都是由分子构成的
④有机物都含碳元素,所以含碳元素的化合物都是有机物
⑤蜡烛燃烧生成CO2和H2O,所以蜡烛的组成里一定含有C元素和H元素
A. ②⑤ B. ②④⑤ C. ①③④ D. ①②③
A.帕拉米韦中含有15个碳原子
B.帕拉米韦的相对分子质量为328g
C.帕拉米韦是由C、H、N、O四种元素组成
D.帕拉米韦分子中C、H、N、O的元素质量比为15:28:4:4
A.用肥皂水鉴别硬水和软水 |
B.用适量氯化钙溶液除去氢氧化钠中混有的少量碳酸钠 |
C.可用水鉴别氢氧化钠和硝酸铵两种白色固体 |
D.用紫色石蕊试液鉴别稀硫酸和蒸馏水 |
A.硫在氧气中燃烧产生蓝紫色火焰,生成无色无味的气体 |
B.把洁净的铜丝放入硝酸银溶液中,溶液由无色逐渐变蓝色 |
C.打开装有浓盐酸试剂瓶的瓶塞,在瓶口上方观察到白烟 |
D.生锈的铁钉放在一定量稀硫酸中,溶液变为浅绿色 |
A.氢氧化钙可用来改良酸性土壤,因为氢氧化钙溶液呈碱性 |
B.活性炭可作冰箱除臭剂,因为活性炭具有吸附性 |
C.汽油能去除油污,因为汽油具有乳化功能 |
D.钨可用于制作白炽灯丝,因为钨的的熔点高且能导电 |
2.选择题- (共11题)
Adding math talk to story time at home is a winning factor for children's math achievement, according to a new research from a university. The study from psychologists Sian Beilock and Susan Levine shows a marked increase in math achievement among children whose families used Bedtime Math, an iPad app that delivers engaging math story problems for parents and children to solve together.
Even children who used the app with their parents as little as once a week saw gains in math achievement by the end of the school year. The app's effect was especially strong for children whose parents tend to be anxious or uncomfortable with math.
Previous research from this group has demonstrated the importance of adults' attitudes about math for children's math success. For example, a recent study found that math-anxious parents who help their children with math homework actually weaken their children's math achievement.
The new findings demonstrate that structured, positive interactions around math at home can cut the link between parents' uneasiness about math and children's low math achievement.
“Many people experience high levels of anxiety when they have to solve a math problem, with a majority of adults feeling at least some worries about math,” said Beilock, professor in Psychology and author of Choke, a book about stress and performance. “These math-anxious parents are probably less likely to talk about math at home, which affects how competent their children are in math. Bedtime Math encourages a dialogue between parents and kids about math, and offers a way to engage in high-quality math interactions in a low-effort, high-impact way.”
Study participants included 587 first-grade students and their parents. Families were given an iPad installed with a version of the Bedtime Math app, with which parents and their children read stories and answer questions involving math, including topics like counting, shapes and problem-solving. A control group received a reading app that had similar stories without the math content and questions related to reading comprehension instead. Children's math achievement was assessed at the beginning and end of the school year. Parents completed a questionnaire about their nervousness with math.
The more times parents and children in the math group used the app, the higher children's achievement on a math assessment at the end of the school year. Indeed, children who frequently used the math app with their parents outperformed similar students in the reading group in math achievement at year's end.
Adding math talk to story time at home is a winning factor for children's math achievement, according to a new research from a university. The study from psychologists Sian Beilock and Susan Levine shows a marked increase in math achievement among children whose families used Bedtime Math, an iPad app that delivers engaging math story problems for parents and children to solve together.
Even children who used the app with their parents as little as once a week saw gains in math achievement by the end of the school year. The app's effect was especially strong for children whose parents tend to be anxious or uncomfortable with math.
Previous research from this group has demonstrated the importance of adults' attitudes about math for children's math success. For example, a recent study found that math-anxious parents who help their children with math homework actually weaken their children's math achievement.
The new findings demonstrate that structured, positive interactions around math at home can cut the link between parents' uneasiness about math and children's low math achievement.
“Many people experience high levels of anxiety when they have to solve a math problem, with a majority of adults feeling at least some worries about math,” said Beilock, professor in Psychology and author of Choke, a book about stress and performance. “These math-anxious parents are probably less likely to talk about math at home, which affects how competent their children are in math. Bedtime Math encourages a dialogue between parents and kids about math, and offers a way to engage in high-quality math interactions in a low-effort, high-impact way.”
Study participants included 587 first-grade students and their parents. Families were given an iPad installed with a version of the Bedtime Math app, with which parents and their children read stories and answer questions involving math, including topics like counting, shapes and problem-solving. A control group received a reading app that had similar stories without the math content and questions related to reading comprehension instead. Children's math achievement was assessed at the beginning and end of the school year. Parents completed a questionnaire about their nervousness with math.
The more times parents and children in the math group used the app, the higher children's achievement on a math assessment at the end of the school year. Indeed, children who frequently used the math app with their parents outperformed similar students in the reading group in math achievement at year's end.
Adding math talk to story time at home is a winning factor for children's math achievement, according to a new research from a university. The study from psychologists Sian Beilock and Susan Levine shows a marked increase in math achievement among children whose families used Bedtime Math, an iPad app that delivers engaging math story problems for parents and children to solve together.
Even children who used the app with their parents as little as once a week saw gains in math achievement by the end of the school year. The app's effect was especially strong for children whose parents tend to be anxious or uncomfortable with math.
Previous research from this group has demonstrated the importance of adults' attitudes about math for children's math success. For example, a recent study found that math-anxious parents who help their children with math homework actually weaken their children's math achievement.
The new findings demonstrate that structured, positive interactions around math at home can cut the link between parents' uneasiness about math and children's low math achievement.
“Many people experience high levels of anxiety when they have to solve a math problem, with a majority of adults feeling at least some worries about math,” said Beilock, professor in Psychology and author of Choke, a book about stress and performance. “These math-anxious parents are probably less likely to talk about math at home, which affects how competent their children are in math. Bedtime Math encourages a dialogue between parents and kids about math, and offers a way to engage in high-quality math interactions in a low-effort, high-impact way.”
Study participants included 587 first-grade students and their parents. Families were given an iPad installed with a version of the Bedtime Math app, with which parents and their children read stories and answer questions involving math, including topics like counting, shapes and problem-solving. A control group received a reading app that had similar stories without the math content and questions related to reading comprehension instead. Children's math achievement was assessed at the beginning and end of the school year. Parents completed a questionnaire about their nervousness with math.
The more times parents and children in the math group used the app, the higher children's achievement on a math assessment at the end of the school year. Indeed, children who frequently used the math app with their parents outperformed similar students in the reading group in math achievement at year's end.
Adding math talk to story time at home is a winning factor for children's math achievement, according to a new research from a university. The study from psychologists Sian Beilock and Susan Levine shows a marked increase in math achievement among children whose families used Bedtime Math, an iPad app that delivers engaging math story problems for parents and children to solve together.
Even children who used the app with their parents as little as once a week saw gains in math achievement by the end of the school year. The app's effect was especially strong for children whose parents tend to be anxious or uncomfortable with math.
Previous research from this group has demonstrated the importance of adults' attitudes about math for children's math success. For example, a recent study found that math-anxious parents who help their children with math homework actually weaken their children's math achievement.
The new findings demonstrate that structured, positive interactions around math at home can cut the link between parents' uneasiness about math and children's low math achievement.
“Many people experience high levels of anxiety when they have to solve a math problem, with a majority of adults feeling at least some worries about math,” said Beilock, professor in Psychology and author of Choke, a book about stress and performance. “These math-anxious parents are probably less likely to talk about math at home, which affects how competent their children are in math. Bedtime Math encourages a dialogue between parents and kids about math, and offers a way to engage in high-quality math interactions in a low-effort, high-impact way.”
Study participants included 587 first-grade students and their parents. Families were given an iPad installed with a version of the Bedtime Math app, with which parents and their children read stories and answer questions involving math, including topics like counting, shapes and problem-solving. A control group received a reading app that had similar stories without the math content and questions related to reading comprehension instead. Children's math achievement was assessed at the beginning and end of the school year. Parents completed a questionnaire about their nervousness with math.
The more times parents and children in the math group used the app, the higher children's achievement on a math assessment at the end of the school year. Indeed, children who frequently used the math app with their parents outperformed similar students in the reading group in math achievement at year's end.
3.填空题- (共4题)
(1)请从H、C、O、N四种元素中选一种或几种元素,写出符合下列要求的化学式.
①人体中含量最多的物质_______; ②最简单的有机物________;
③厨房中的酸性调味品 ; ④能使紫色石蕊试液变蓝的气体 。
(2)从生活走进化学,从化学走向社会。请回答下列问题:
①日常生活中的自来水属于 (填“纯净物”或“混合物”);自来水中的游离氯有少量可转变成氯离子,氯离子的符号是 。
②四月是鲜花盛开的季节,漫步在花丛中,会闻到花香,请用分子的观点解释闻到香味的原因___________________________________。
③在普通汽油中加入适量的燃料乙醇可制得乙醇汽油,用乙醇汽油作为汽车燃料越来越普遍。请你答出使用乙醇汽油的优点(一条即可)_____________________ __________。

(1)指出编号仪器名称:① ,② 。
(2)实验室利用A装置可制取氧气,反应的化学方程式为 。
(3)实验室制取并收集氢气应选择的装置是 (从A~E中选择),反应的化学方程式为 ,使用该套装置制取气体的优点是 ,若用F装置收集氢气,则气体应从 端进入。
(4)用块状石灰石和稀盐酸反应,观察到气泡逸出不明显后,测得试管内残留液的pH如下图中a点所示,向残留液中逐渐滴入碳酸钠溶液,并用pH计连续监测测得的曲线如下图,(pH为纵坐标,时间(秒)为横坐标)。请写出曲线中bc段发生反应的化学方程式: ,cd上升的原因是 。

(1)实验室用过氧化氢制氧气 ()反应;
(2)用氢氧化铝治疗胃酸过多______________________________( )反应;
(3)硝酸银不稳定,见光易分解,生成一种金属单质,一种能供给呼吸的气体,还有二氧化氮气体_________________________________________。


上述流程中涉及的部分反应的化学方程式为:
Al(OH)3 + NaOH === NaAlO2 + 2H2O (NaAlO2可溶于水)。
请回答下列问题。(1)上述氧化物中能与水反应的是____________。
(2)粉煤灰与过量的盐酸反应的主要化学方程式是__________________________(写出其中的一个)。
(3)操作2的名称是________。
(4)固体Ⅱ含有的主要物质的化学式为___________________。
(5)溶液Ⅱ与过量的CO2反应的化学方程式为:NaAlO2 + CO2 + 2H2O === Al(OH)3↓ + ___________。
4.实验题- (共1题)
1、该牙膏摩擦剂由碳酸钙、氢氧化铝组成;
2、牙膏中其它成分遇到盐酸无气体生成;
3、碱石灰的主要成分为生石灰和氢氧化钠固体。
利用下图所示装置(图中夹持仪器略去)进行实验,充分反应后,测定B中生成的BaCO3沉淀的质量,以确定碳酸钙的质量分数。请回答下列问题:

(1)B中反应生成BaCO3的化学方程式是 。
(2)C装置的作用是 。
(3)下列各项措施中,不能提高测定准确度的是 (填序号)。
|
(4)有同学认为该装置测定出来的碳酸钙质量分数会偏低,他的理由是
,解决方法是 。
(5)某同学认为不必测定B中生成的BaCO3质量,将B中的Ba(OH)2溶液换成浓H2SO4 ,通过测定C装置反应前后的质量差也可以测定CaCO3的质量分数。实验证明按此方法测定的结果明显偏高,原因是 。
(6)实验中准确称取8.00g样品三份,进行三次测定,测得BaCO3平均质量为3.94g 。请计算样品中碳酸钙的质量分数。(写出计算过程)
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【1】题量占比
单选题:(9道)
选择题:(11道)
填空题:(4道)
实验题:(1道)
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【2】:难度分析
1星难题:0
2星难题:0
3星难题:0
4星难题:2
5星难题:0
6星难题:9
7星难题:0
8星难题:2
9星难题:1