问题 选择题

下列叙述正确的是

A.0.1 mol·L-1醋酸溶液中:c(H+)= c(CH3COO)+c(OH)

B.中和pH与体积都相同的硫酸和醋酸,消耗NaOH的量后者大于前者

C.同温同浓度的NaOH和澄清石灰水中,水的电离程度相同

D.NaHCO3溶液中:c(Na+)>c(HCO3)>c(H2CO3)>c(OH)>c(H+)

答案

AB

醋酸溶液中带电离子只有H+、CH3COO、OH,由电荷守恒原理可知,c(H+)= c(CH3COO)+c(OH),故A正确;硫酸和醋酸分别是强酸、弱酸,溶质浓度相同时溶液pH:硫酸<醋酸,而溶液pH相同时溶质浓度:硫酸<<醋酸,则pH和体积都相同时溶质的物质的量:硫酸<<醋酸,则醋酸消耗NaOH的量远远大于硫酸,故B正确;NaOH、Ca(OH)2分别是一元强碱、二元强碱,同温同浓度溶液中c(OH):NaOH<Ca(OH)2,强碱电离产生的c(OH)越大,水的电离平衡(H2OH++OH)越向左移动,水的电离程度越小,则NaOH溶液中水的电离程度较小,故C错误;电离程度:NaHCO3>H2O,碳酸氢钠溶液呈弱碱性,说明其水解程度(HCO3+H2OH2CO3+OH)大于电离程度(HCO3H++CO32),由于HCO3电离程度很小,可以忽略不计,而水的电离(H2OH++OH)受到促进,则溶液中c(Na+)>c(HCO3)>c(OH)>c(H2CO3)>c(H+),故D错误。

完形填空

[1]Having good communication skills is really important in every walk of life. The right method of communication is therefore very important in whatever you do. Here are some effective ways to improve communication skills that can help you to bring about a change in many aspects of your life.

Observe and listen

[2] Look and observe the people around you who make easy and effective conversations. This should give you an insight and an understanding that could open up new ways for better ways to communicate with others. Meanwhile,communication is not just about speaking effectively and in an impressive manner, you also need to be a good listener. It is important to be a good listener in order to understand what the other person is saying, and reply accordingly.

Take Your Time

[3] Think twice before you speak once. When conversing with someone, remember that you need to take time to think before you react to what is being said. It is an excellent communication skill to take a few moments and process all the information before you respond.

Keep it Light

[4] Having a sense of humor helps to make any conservation light and fun to be in! Develop ______________ and use it. As a good communicator, one should know where to draw the line with humor.

Body Language

[5] Sporting the right kind of body language is another important key factor in improving communication skills. Maintain eye contact as you speak; sit and stand in an erect (直立的) position, and have a firm handshake; do not give wrong signals by crossing your arms and legs; avoid moving your body or playing with small things frequently. Always remember that your gestures say a lot about your personality as an individual.

小题1:What is the main idea of the passage?(no more than 6 words)

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小题2:According to the writer, why is it important to be a good listener? (no more than 20 words)

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小题3:What is the meaning of the underlined word “conversing” in Paragraph 3? (no more than 3 words)

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小题4:Fill in the blank in Paragraph 4 with proper words. (no more than 5 words)

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小题5:List 3 gestures that you should avoid while communicating with others. (no more than 15 words)

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