问题 填空题

连接键盘和鼠标的 【18】 接口物理上虽然相同,但是二者不可以混用。

答案

参考答案:PS/2

解析: PC机上的两个PS/2接口一个连接鼠标,一个连接键盘,虽然外形一样,但是不可以混用。

填空题

Ⅰ.电离平衡常数(用K表示)的大小可以判断电解质的相对强弱。25℃时,有关物质的电离平衡常数如下表所示:

化学式HFH2CO3HClO
电离平衡常数

(K)

7.2×10-4K1=4.4×10-7

K2=4.7×10-11

3.0×10-8
 

(1)物质的量浓度均为0.1mol/L的下列四种溶液:①Na2CO3溶液 ②NaHCO3溶液 ③NaF溶液 ④NaClO溶液。依据数据判断pH由大到小的顺序是______________。

(2)25℃时,在20mL0.1mol·L—1氢氟酸中加入VmL0.1mol·L—1NaOH溶液,测得混合溶液的pH变化曲线如图所示,下列说法正确的是_______。

A.pH=3的HF溶液和pH=11的NaF溶液中,由水电离出的c(H+)相等

B.①点时pH=6,此时溶液中,c(F)-c(Na+)=9.9×10-7mol/L

C.②点时,溶液中的c(F)=c(Na+)

D.③点时V=20mL,此时溶液中c(F)<c(Na+)=0.1mol·L—1

(3)已知25℃时,①HF(aq)+OH(aq)=F(aq)+H2O(l)  ΔH=-akJ·mol—1

②H+(aq)+OH(aq)=H2O(l)        ΔH=-bkJ·mol—1

氢氟酸的电离方程式及热效应可表示为________________________。

(4)长期以来,一直认为氟的含氧酸不存在。1971年美国科学家用氟气通过细冰末时获得HFO,其结构式为H—O—F。HFO与等物质的量的H2O反应得到HF和化合物A,则每生成1molHF转移_______mol电子。

Ⅱ.氯化硫酰(SO2Cl2)主要用作氯化剂。它是一种无色液体,熔点–54.1℃,沸点69.1℃。氯化硫酰可用干燥的二氧化硫和氯气在活性炭催化剂存在下反应制取:

SO2(g)+Cl2(g)SO2Cl2(l)  △H=–97.3kJ·mol—1

(1)试写出常温常压下化学平衡常数K的表达式:K=_________________;

(2)对上述反应,若要使化学平衡常数K增大,化学反应速率v也增大,可采取的措施是_____(选填编号)。

a.降低温度                   b.移走SO2Cl2

c.增加反应物浓度             d.无法满足上述条件

(3)下列描述中能说明上述反应已达平衡的是____________(选填编号)。

a.υ(Cl 2)=υ(SO2)               b.容器中气体压强不随时间而变化 

c.c(Cl 2) : c(SO2)=1:1           d.容器中气体颜色不随时间两变化

(4)300℃时,体积为1L的密闭容器中充入16.20g SO2Cl2,达到平衡时容器中含SO2 7.616g。若在上述中的平衡体系中,再加入16.20g SO2Cl2,当再次达平衡时,容器中含SO2的质量范围是________________________。

单项选择题 案例分析题

Women are also underrepresented in the administration and this is because there are so few women full professors. In 1985,Regent Beryl Milburn produced a report blasting(轰动)the University of Texas System administration for not encouraging women.The University was rated认为 among the lowest for the system.In a 1987 update ,Milburn commended the progress that was made and called for even more improvement.

One of the positive results from her study was a System-wide program to inform women of available administrative jobs.

College of Communication Associate Dean Patrica Witherspoon,said it is important that woman be flexible when it comesto relocating if they want to rise in the ranks.

Although a woman may face a chilly climate on campus , many times in order for her to succeed , she must rise above the problems around her and concentrate on her work.

Until women make up a greater percentage of the senior positions in the University and all academia,inequities will exist存在.

"Women need to spend their energies(精力energy) and time doing scholarly activities that are important here at the University." Spirduso said. "If they do that will be successful in this system.If they spend their time in little groups mourning the sexual discrimination that they think exists here, they are wasting valuable study time."

Which of the following statements is true?()

A.the number of women professors in the University in 1987 was greater than that of 1985

B.the number of women professors in the University in 1987 was smaller than that of 1985

C.the number of women professors was the same as that of 1985

D.more and more women professors thought that sexual discrimination did exit in the University