问题 填空题

据媒体披露,顾客反映:某连锁餐饮企业“ XX 豆浆”所提供的油条有氨气的异味。经记者采访,店方承认连锁店是用碳酸氢铵和水配成溶液发的面,使油条膨松。以卜是记者与“ xx 豆浆”品控部某经理的对话:

记者:“为什么部分油条有氨气的气味? ”

经理:“我们对油条中的碳酸氢铵是定量化标准,对各门店的油条制作采取规范化标准。”“顾客感到味呛,可能是油温不够所致。因为今天的厨师是新手。”

对稍有化学知识的人来说,经理的话可谓一语道破大机。由以上信息,你可以得出:

( 1 )碳酸氢铵的物理性质是                           

( 2 )碳酸氢铵的化学性质是                                 ;

( 3) 传统膨化剂使用的是 NaHC03,其加热后分解生成碳酸钠、水和二氧化碳,请写出该反应的化学方程式                                     

答案

( 1 )物理性质是  易溶于水                        

( 2 )化学性质是                受热易分解                 ;

( 3)化学方程式 2 NaHCO3  Na2CO3+H2O+ CO2                        

(1)用碳酸氢铵和水配成溶液,说明碳酸氢铵能溶于水,这是碳酸氢氨的物理性质;

(2)使油条蓬松并有氨气的异味,说明碳酸氢氨受热易分解生成二氧化碳和氨气,是碳酸氢氨的化学性质;

(3)NaHCO3加热后分解生成碳酸钠、最常见的溶剂和二氧化碳,化学方程式为:2NaHCO3Na2CO3+H2O+CO2↑.

故答案为:

(1)可溶于水的固体;

(2)受热易分解(3)2NaHCO3Na2CO3+H2O+CO2↑.

单项选择题
阅读理解

Eleven months ago, an act of good sportsmanship(体育精神)changed a girls’ running race into something bigger.

Jenna Huff received a national sportsmanship award from the US Olympic Committee for what she did for Deb Guthmann.

In the race, Jenna was behind Deb until the final few meters of the 5-kilometer race.

Then something awful happened. Deb’s right hip(髋部)broke. She screamed in pain and stopped.

Jenna had never met Deb and had been taught to pass every runner she could to win.

Instead, Jenna stopped with no hesitation.

“Come on.” Jenna told Deb. “We’re going to run.”

Jenna took Deb’s left elbow with her right hand. She helped her jog the last few meters. At the finishing line, she pushed Deb in front of her, reasoning Deb would have beaten her anyway if not for the injury. That act helped Deb’s team win the regional race and advance to the state meet.

Both girls are now 17.

Jenna is still an athlete for her school.

She and her parents went to Colorado to accept an award for the national sportsmanship award. Jenna had to give a five-minute speech to the crowd, a crowd which included a number of former Olympians. “I’m pretty scared about my speech,” Jenna said the other night when we talked on the phone. “You want to hear part of it?” She read me one part including the words from Albert Einstein: “Each of us comes for a short visit, not knowing why, yet sometimes seeming to a divine(神圣的)purpose. From the standpoint of daily life, however, there is one thing we do know:That we are here for the sake of(为了)others.”

Deb is also still running. She received a full scholarship to Emmanuel College in Franklin Springs, Georgia. The award was because of her excellent academic record and great sports potential.

But she recently got hurt again and was unable to run for weeks.

Even so, I am confident Deb will write a happier ending for herself one day. Both of these young women make you feel confident about the future. They are strong, compassionate(富于同情心的)and smart.

As Einstein said-and as Jenna showed 11 months ago— “we are here for the sake of others”.

小题1:The story is intended to __________.

A.tell us an unexpected story in the girls’ running race

B.introduce a famous sportswoman

C.show the beauty of good sportsmanship

D.remind athletes to pay attention to their safety during the race小题2:The reason why Jenna pushed Deb in front of her at the finishing line is that __________.

A.she wanted to get the prize

B.she thought she didn’t match Deb in reality

C.she helped Deb’s team to win the regional race

D.Deb had been injured小题3:Deb received a full scholarship to Emmanuel College because __________.

A.she is still running

B.she was good at her academy and sports

C.she showed the good sportsmanship in the race

D.she never gave up even though she had been injured小题4:What can we know from the passage?

A.Jenna was the last one to reach the finishing line.

B.Deb went to Colorado to accept the prize with her parents.

C.The author had a face-to-face interview with Jenna the other night.

D.Helping each other can make a big difference to people’s lives.