(1)已知: ①Fe(s)+O2(g)=FeO(s) ΔH=-272.0 kJ·

题型:填空题

问题:

(1)已知:

①Fe(s)+O2(g)=FeO(s) ΔH=-272.0 kJ·mol1

②2Al(s)+O2(g)=Al2O3(s) ΔH=-1675.7 kJ·mol1

Al和FeO发生铝热反应的热化学方程式是____________________________________

(2)某可逆反应在不同条件下的反应历程分别为A、B(如上图所示)。

①根据图判断该反应达到平衡后,其他条件不变,升高温度,反应物的转化率________(填“增大”“减小”或“不变”);

②其中B历程表明此反应采用的条件为________(选填序号)。

A.升高温度      B.增大反应物的浓度   C.降低温度  D.使用催化剂

(3)1000 ℃时,硫酸钠与氢气发生下列反应:Na2SO4(s)+4H2(g)Na2S(s)+4H2O(g)

该反应的平衡常数表达式为________________________________;

已知K1000 <K1200 ,若降低体系温度,混合气体的平均相对分子质量将会________(填“增大”“减小”或“不变”)。

(4)常温下,如果取0.1 mol·L1 HA溶液与0.1 mol·L1 NaOH溶液等体积混合(混合后溶液体积的变化忽略不计),测得混合液的pH=8。

①混合液中由水电离出的OH浓度与0.1 mol·L1 NaOH溶液中由水电离出的OH浓度之比为________;

②已知NH4A溶液为中性,又知将HA溶液加到Na2CO3溶液中有气体放出,试推断(NH4)2CO3溶液的pH________7(填“<”“>”或“=”);相同温度下,等物质的量浓度的下列四种盐溶液按pH由大到小的排列顺序为(填序号)________。

a.NH4HCO3  b.NH4A       c.(NH4)2CO3  d.NH4Cl

考点:焓变、反应热中和热燃烧热
题型:填空题

A small ,white envelope stuck among the branches of our Christmas tree and it has been there for the past ten years or so.

It all began because my husband Justin hated Christmas—oh, not the true meaning of Christmas.Overspending was one thing, but compared to the difficult experience of choosing gifts—running around at the last minute to get a tie for Uncle Harry and a pair of gloves for Grandma…,spending money is nothing. I felt too tired to think of any special gifts.

Knowing Justin felt the same way, I decided one year not to buy the usual shirts, sweaters, ties and so on. I reached for something special just for Justin. The inspiration came in an unusual way.

Our son Kevin, who was 12 that year, was wrestling (摔跤)at the junior level at the school he attended; and shortly before Christmas, there was a match against a team sponsored (赞助) by an inner-city church.These youngsters, dressed in such worn-out shoes that shoe strings seemed to be the only thing holding them together, while our boys were in their blue and gold uniforms and new wrestling shoes.

As the match began, I was shocked to see that the other team were wrestling without wearing helmets (头盔) to protect their ears. Well, our boys ended up defeating them. We took every weight class.

Justin, seated beside me, shook his head sadly, “I wish just one of them could have won,” he said. “They have a lot potential (潜力) , but losing like this could take the heart out of them.” Justin loved kids—all kids, and he knew them, having coached little league football and baseball. That’s when the idea for his present came. That afternoon, I went to a local sporting goods store and bought different kinds of wrestling helmets and shoes. I sent them to inner-city church without leaving my name.

On Christmas Eve, I placed the envelope on the tree, the note inside telling Justin what I had done and that was his gift from me. His smile was the brightest thing about Christmas that year and since then the envelope has become the highlight of our Christmas.

小题1: Justin hated Christmas because _____.

A.he didn’t enjoy receiving gifts

B.he had a hard time choosing gifts

C.he spent too much money buying gifts

D.he disliked putting gifts under the Christmas tree小题2:We know from the passage that the team sponsored by inner-city church_____.

A.were well dressed

B.paid no attention to safety

C.feared Kevin’s team

D.couldn’t afford a helmet小题3: How did Justin feel about the team’s failure ?

A.Upset

B.Angry

C.Hopeless

D.Shameful小题4: Why did the writer send gifts to the inner-city church without leaving her name ?

A.To avoid being thanked

B.To play a joke on Justin

C.To give Justin a surprise

D.To protect her private information小题5:Which of the following can be the best title for the passage?

A.The Church Gift

B.A Special Note

C.The White Envelope

D.A Christmas Card

题型:填空题

如图所示,两列简谐横波均沿x轴传播,传播速度的大小相等.其中一列沿x轴正方向传播(图中实线),另一列沿x轴负方向传播(图中虚线).这两列波的频率相等,振动方向均沿y轴方向.则关于图中x=1、x=2、x=3、x=4各点的振动,正确的说法是

[ ]

A.x=2、x=4的点振动最强烈

B.x=2、x=4的点振动最弱

C.x=1、x=3的点振动最强烈

D.x=1、x=3的点振动的振幅最小

题型:填空题

鲁迅先生说:陶渊明诗“论客所佩服的‘悠然见南山’之处,也还有“精卫衔微木,(),刑天舞干戚,()之类的‘()式。在证明着他并非整天整夜的飘飘然。

题型:填空题

接触性皮炎最常见的病因是()

A.花粉

B.动物皮毛

C.化学性物质

D.微生物

E.以上都不是

题型:填空题

某批进口货物,自载运货物的运输工具申报进境之日起,已超过3个月,收货人或其代理人仍未向海关申报。这种情况海关应采取下列选项中的( )方式处理。

A.将货物提取变卖,价款扣除各项费税后,余款保存一年,经收货人申请可以发还,逾期无人申请的上缴国库

B.将货物扣留,待收货人或其代理人报关时罚款处理

C.将货物没收,全部变价上缴国库

D.将货物扣留,待收货人或其代理人报关时,除按日征收滞报金外,加处罚款

更多题库