问题 选择题

某温度时,在2L密闭容器中气态物质X和Y反应生成气态物质Z,它们的物质的量随时间的变化如图所示,则下列说法错误的是(   )

A.反应的化学方程式是X+2Y 2Z

B.该反应在0-3min时间内产物Z的平均反应速率0.083mol·L1·min1

C.在3分钟时Y和Z的浓度相等

D.其他条件不变,升高温度,若正反应速率增大,则逆反应速率将减小

答案

答案:D

由图像可知X、Y的物质的量减少,Z的物质的量增加,所以X、Y是反应物,Z是生成物。反应进行到3min时,X、Y、Z的物质的量分别为0.75mol、0.5mol、0.5mol,即X、Y、Z的变化量分别为0.25mol、0.5mol、0.5mol,所以方程式为X+2Y  2Z。反应在0-3min时间内产物Z的平均反应速率为0.083mol·L1·min1。温度升高反应速率一定增大,因此选项D不正确。答案是D。

单项选择题 共用题干题
单项选择题

Almost every day the media discovers an African American community fighting some form of environmental threat from land fills, garbage dumps, petrochemical plants, refineries, bus depots, and the list goes on. For years, residents watched helplessly as their communities became dumping grounds.
But citizens didn’t remain silent for long. Local activists have been organizing under the mantie of environmental justice since as far back as 1968. More than three decades ago, the concept of environmental justice had not registered on the radar screens of many environmental or civil rights groups. But environmental justice fits squarely under the civil rights umbrella. It should not be forgotten that Dr. Martin Luther King Jr. went to Memphis on an environmental and economic justice mission in 1968, seeking support for striking garbage workers who were underpaid and whose basic duties exposed them to environmentally hazardous conditions.
In 1979, a landmark environmental discrimination lawsuit filed in Houston, followed by similar litigation efforts in the 1980s, rallied activists to stand up to corporations and demand government intervention.
In 1991, a new breed of environmental activists gathered in Washington, D.C. , to bring national attention to pollution problems threatening low-income and minority communities. Leaders introduced the concept of environmental justice, protesting that Black, poor and working-class communities often received less environmental protection than White or more affluent communities. The first National People of Color Environmental Leadership Summit effectively broadened what "the environment" was understood to mean. It expanded the definition to include where we live, work, play, worship and go to school, as well as the physical and natural world. In the process, the environmental justice movement changed the way environmentalism is practiced in the United States and, ultimately, worldwide.
Because many issues identified at the inaugural summit remain unaddressed, the second National People of Color Environmental Leadership Summit was convened in Washington, D.C. , this past October. The second summit was planned for 500 delegates ; but more than 1,400 people attended the four-day gathering.
"We are pleased that the Summit Ⅱ was able to attract a record number of grassroots activists, academicians, students, researchers, planners, policy analysts and government officials. We proved to the world that our movement is alive and well, and growing," says Beverly Wright, chair of the summit. The meeting produced two dozen policy papers that show powerful environmental and health disparities between people of color and Whites.

In 1968, Martin Luther King Jr. went to Memphis to help the garbage workers ______.

A.get relieved of some of their basic duties

B.know what environmental justice was

C.fight for better working conditions

D.recognize their dangerous surroundings