问题 问答题

实验室中现有一种固体混合物,其中可能含有Na2SO4、BaCl2、(NH42SO4、CuO、Na2CO3五种物质中的两种或多种.按如图所示进行实验,出现的现象如图中所述(设过程中所有可能发生的反应都恰好完全进行).

试根据实验过程和发生的现象判断:

(1)气体B能使紫色的石蕊试液变______色.

(2)在混合物A中,一定存在的物质有______种.

(3)在溶液C中,一定大量存在的阳离子是______.

(4)写出步骤③中一定发生的一个化学反应的方程式______.

(5)滤渣D是(写化学式)______.

(6)固体混合物里,上述五种物质中,还不能确定存在的物质是(写化学式)______,得此结论的理由是______.

答案

(1)气体B通入澄清石灰水石灰水变浑浊,故该气体是二氧化碳,二氧化碳能够使紫色的石蕊试液变红;

(2)蓝色沉淀是氢氧化铜,因此原混合物中一定有氧化铜;二氧化碳和氢氧化钙反应生成碳酸钙白色沉淀和水,石灰水变浑浊,因此原混合物中Na2CO3一定存在;因为滤渣D不溶于稀硝酸,因此D是硫酸钡,那么原混合物中一定有BaCl2,由于C加入氢氧化钠溶液后会用气体产生,则该气体是氨气;所以固体中一定含有硫酸铵,硫酸铵能够与氯化钡反应生成硫酸钡沉淀,硫酸钠也能,故硫酸钠是否含有无法确定;所以固体中一定含有4中物质;

(3)溶液C中由以上分析可知含有的阳离子是Cu2+、NH4+

(4)步骤③中一定发生的反应是氯化铜和氢氧化钠的反应(氯化铵和氢氧化钠也可),方程式为:CuCl2+2NaOH═Cu(OH)2↓+2NaCl;

(5)由以上分析可知该滤渣是BaSO4

(6)由以上分析可知该混合物中还不能确定存在的物质是硫酸钠,因为滤渣D是BaSO4,而氯化钡和硫酸钠或硫酸铵都能生成该沉淀,故到底是有硫酸铵一种,还是两者都有无法确定;

阅读理解

Our spiritual intelligence quotient (精神智商),or SQ, helps us understand ourselves, and live fuller, happier lives.

Though we're all born with SQ, most of us don’t even realize that we have it. Fortunately, you don't have to sign up for classes to learn how to improve your SQ. Here are some simple steps that can lead you to this new level of understanding.

Sit Quietly. The process of developing spiritual intelligence begins with solitude (独处) and silence. To tune in to your spirit, you have to turn down the volume (强度) in your busy, noisy, complicated life and force yourself to do nothing at all. Start small by creating islands for silence in your day. In the car, instead of listening to the music, use the time to think. At work, shut the door to your office between meetings, take a few breaths and let them out very, very slowly. Enjoy the stillness in your home after the kids are finally in bed.

Step Outside.  For many people, nature sets their spirit free. Go outside to watch a beautiful sunset. If you are walking with the dog, take the time to admire flower in bloom; follow the light of a bird and watch clouds float overhead.

Ask Questions of Yourself. Ask open-ended questions, such as "What am I feeling? What are my choices? Where am I heading?"

But don't expect an answer to arrive through some supernatural form of e-mail. "Rarely do I get an immediate answer to my question," says Reverend Joan Carter, a Presbyterian minister in Sausalito, California. “But later that day I suddenly find myself thinking about a problem in a perspective(角度) I never considered before.”

Trust Your Spirit. While most of us rely on gut(本能的) feeling to realize danger, spiritual intelligence pushes us, not away from, but towards some action that will lead to a greater good.

68. The passage is mainly about           .

A. what your SQ is and in what way it can benefit our life

B. what your SQ is and in what way it can be improved

C. the relationship between your SQ and your life

D. advantages and disadvantages of SQ

69. The underlined phrase "tune in to your spirit" in the third paragraph probably means to _____.

A. get your spirit relaxed                   B. keep up your spirit

C. keep seated quietly                      D. change your spirit

70. The author mentions the example of Reverend Joan Carter to show that            .

A. there are no immediate answers to your questions

B. e-mails can't keep working out a problem

C. the more questions you ask, the better answers you'll get      

D. changing your way of thinking might help you solve a problem

71. From the passage, we can know that the most important thing to improve your SQ is      .

A. a peaceful mind    B. deep thought   C. spare time and hobbies   D. good spirits

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