问题 填空题

(8分)(1)某温度时,在2 L密闭容器中,X、Y、Z三种物质的物质的量随时间变化曲线如下图所示。由图中数据分析,该反应的化学方程式为:____________________________

(2) 用Z表示从0—2min内该反应的平均反应速率为    

____________________

(3) 某时刻t(t﹤5min)测得Y、Z两者的物质的量之比为

3:1,则X的转化率为_________

(4) 该条件下,能说明反应已达到平衡状态的是       

a.容器内z物质的量浓度为0.25mol/L

b.正反应和逆反应的速率都为0       

c.容器内X、Y、Z物质的量之比为1∶3∶2

d.容器内X气体的体积分数不变  

e. 单位时间内消耗3a mol X,同时生成2a mol Z

答案

(每空2分)(1)3X+Y2Z     (2)0.05mol·L-1·min-1

(3)30%              (4)a d

题目分析:(1)由图象可以看出,反应中X、Y的物质的量减少,应为反应物,Z的物质的量增多,应为生成物,当反应进行到5min时,△n(X)=0.6mol,△n(Y)=0.2mol,△n(Z)=0.4mol,则△n(X):△n(Y):△n(Z)=3:1:2,参加反应的物质的物质的量之比等于化学计量数之比,则反应的方程式为:3X+Y2Z;

(2)从0—2min内Z的物质的量变化为0.2mol,则浓度变化量为0.1mol/L,故反应速率为0.1mol/L÷2min=0.05mol·L-1·min-1

(3)根据反应3X+Y2Z可 * * 段式如下:

3X+Y2Z

起始物质的量   1   1      0.1

变化物质的量   3x  x      2x

某时刻物质的量 1-3x 1-x     0.1+2x

故有:(1-x):(0.1+2x)=3:1,解得x=0.1,故X的转化率为0.3/1 ×100%=30%;

(4)a.容器内z物质的量浓度为0.25mol/L,根据图示可知Z的浓度不再改变,故已达到平衡;b.正反应和逆反应的速率都为0,则反应停止,不是平衡状态;c.容器内X、Y、Z物质的量之比为1∶3∶2,不能说明是否不变,不一定平衡;d.容器内X气体的体积分数不变,说明已达平衡;e. 单位时间内消耗3a mol X,同时生成2a mol Z ,均为同一方向,不可说明是否平衡;故选ad。

单项选择题
阅读理解

阅读理解。

     As is known, healthy foods can help save your life. Now, here is a list of healthy foods that can save your

memory. It is best that every person knows what he eats, as he takes in, can make or break himself, in terms

of health.

     Fish is helpful in regaining back the kind of memory that a person once has. Eating fish can help you save

the trouble of forgetfulness. Vegetables rich in fiber and other dark and green leafy kinds are very suitable for

people who want to avoid mental blocks. These foods contain high units of vitamin E.

     Another food that is considered having different effects on preventing this brain deficiency (缺陷) is

avocado (鳄梨), which is also rich in vitamins E and C. It is really good to know these healthy foods that can

save your memory are always at hand so as to help you in your fight against diseases. Sunflower seeds are

regarded as Vitamin C-powered seeds and also give you enough energy.

     As for red wine, do not over consume it, as it is said to have to be taken in moderate amounts in order to

help the body. Over-drinking can cause illness and like anything else. This is considered as one of the healthy

foods that can save your memory; alcohol can otherwise lose it.

     It is better to consume colored bread, rice and whole grains for you to get the best out of fiber. These

foods can lower the body's risk of being infected with Alzheimer's disease (老年痴呆病).

     Knowing the healthy foods that can save your memory is living the life that you have longed and desired.

Among the others, the best, of course, is exercise. Taking in different kind of exercises, physical activities

or sports can keep both your body and mind healthy.

1. If you suffer from loss of memory, you _____.

A. should eat cucumbers and cabbages

B. can drink as much wine as possible

C. had better take in fish in your meals

D. may as well take more vitamin C

2. To prevent mental disease from happening, _____.

A. people are advised to take avocados

B. it is best to eat vegetables high in fiber

C. it is better to have more sunflower seeds

D. red wine is the first and best choice

3. Which of the following is the most important for health?

A. Drinking a proper amount of red wine every day.

B. Eating bread made of whole grains.

C. Adding Vitamin C-powered seeds to meals.

D. Taking moderate exercise every day.

4. How many means for health does the author mention in the passage?

A. Six.

B. Seven.

C. Eight.

D. Nine.

5. Which of the following is most suitable for the passage? (① = Para.l ②= Para.2③ = Para.3④ = Para.4

    ⑤= Para. 5⑥ = Para. 6)

A.  B.  C.  D.