问题 选择题

右图表示可逆反应mA(g)+nB(g)pC(g)在不同温度(T)、压强(P)下,生成物C的质量分数C%的变化情况。下列关于该正反应热效应及方程式中A. B. C的化学计量数的判断中,正确的是

A.吸热反应,m+n<p    B.吸热反应,m+n>p

C.放热反应,m+n<p    D.放热反应,m+n>p

答案

答案:C

题目分析:根据图像可知,温度为T2时反应首先达到平衡状态,则T2大于T1。温度高C的百分含量低,这说明升高温度平衡逆反应方向移动,因此正反应是放热反应;同样分析可知,压强为P2时反应首先达到平衡状态,则P2大于P1。压强高C的百分含量低,这说明增大压强平衡逆反应方向移动,因此正反应是体积增大的可逆反应,即m+n<p,答案选C。

点评:该题是高考中的常见题型,属于中等难度的试题。试题综合性强,旨在考查学生灵活运用基础知识解决实际问题的能力。该类试题需要明确的是在分析有关图像时应该注意:一、ν-t 图像或 c-t 图像:1.ν-t 图像:分清正逆反应,分清各因素(浓度、温度、压强、催化剂)对反应速率和平衡移动的影响。 二、平衡图像 1.出现拐点的图像:分析依据“先拐先平”。在转化率-时间图像或物质的百分含量-时间图像中,先出现拐点的曲线先达到平衡(代表温度高或压强大或使用合适的催化剂等)。

阅读理解

阅读理解。

The Home of My People

     When Lewis and Clark stepped onto the Weippe Prairie in present-day Idaho in September 1805, they

met the Nez Perce Indians. In the following years, the white explorers (探险者) began to fight with the

Indians for their land. Some Nez Perce chiefs signed agreements with the U.S. government, selling part

of their lands. But the government always broke those agreements and demanded more land.

     Other chiefs refused to go along with the government's plans. The most famous was Chief Joseph,

whose people lived in the Wallowa Valley(present-day Oregon).  "In order to have all people understand

how much land we owned," he once explained,"my father planted poles around it and said:  'Inside is the

home of my people…It circled around the graves (坟墓) of our fathers, and we will never give up these

graves to any man. '

     But in 1874, the U.S. government declared the valley open for white settlement and ordered the Nez

Perce onto a reservation (保留地). Seeing that resistance was useless, Chief Joseph agreed to move.

     Later, fighting broke out between the Nez Perce and U.S. soldiers. Chief Joseph tried to lead his people

to Canada, winning several battles against the soldiers during their flight. But finally, he was forced to give

in.

1. Which historic site (on the map)lies in the south of today's Nez Perce Reservation?

A. Buffalo Eddy.

B. Dug Bar.

C. Joseph Canyon Viewpoint.

D. Chief Looking Glass Camp.

2. What can we learn about the Nez Perce lands from the map?

A. They were in the state of Oregon.

B. They have become a historic site.

C. They have become much smaller.

D. They were limited to the Wallowa Valley.

3. From Paragraph 3, we know that the Indians wanted to ______.

A. show off their land

B. keep their land

C. turn their place into a graveyard

D. build their homes around the poles

单项选择题 A1/A2型题