问题 填空题

已知:25℃时,弱电解质的电离平衡常数:Ka(CH3COOH)=1.8×10-5,Ka(HClO)=3.0×10-8,Ka(HF)=

3.5×10-4,Ka1(H2CO3)=4.3×10-7,Ka2(H2CO3)=5.6×10-11。回答下列问题:

(1)25℃时,将10 mL pH =1的CH3COOH溶液和10 mL pH =1的HF溶液分别与10 mL 0.1mol/L的NaHCO3溶液混合。

①画出产生的气体体积(V)随时间(t)变化的示意图。

②反应结束后所得的两溶液中,c(CH3COO-)_______c(F-)(填“>”、“<”或“=”)。

(2)25℃时,将少量CO2通入足量NaClO中,写出该反应的离子方程式_________,此反应的平衡常数K=

________________。

(3)0.18 mol/LCH3COONa溶液的pH为____。

答案

(1)①

②>

(2)CO2+H2O+ClO=HCO3-+ HClO;14.3

(3)9

完形填空
A man was walking along the street when he saw a woman struggling with a large package(包裹). It was half in and half out of her car.
He was a         kind of man so he went up to the woman and said, "Let me give you a hand with that package. It looks very        ."
"That's very kind of you," the woman said. "I'm having a lot of         with it. I think it's stuck."
"Together we'll soon move it," the man said. "I'll get into the         and take the other end."
"Oh, that's very        . Thank you so much," the woman said gratefully. He got into the back         of the car and took hold of the other end of the package.
"Right," he said, "I'm ready." And he began to push with all his        .
For several minutes the man and the woman struggled with the package. Soon they were both red in face and out of        .
"Let's pause for a minute," the man said. "You're right. It really is        ."
They paused for a few         to wipe the perspiration from their faces and get their breath back.
Then the man said, "Let's try again. Are you        ?"
They         took hold of the package again.
"One, two, three!" the man said, and again they         their struggle with the package.
At last, when they were both        , the man said, "I'm sorry, but the package really seems to be        stuck. I don't think there's any way we can get it out of the car."
"Get it out of the car!" the woman cried. "You fool! I'm trying to get it in!"
小题1:
A.helpfulB.carefulC.usefulD.hopeful
小题2:
A.bigB.smallC.heavyD.light
小题3:
A.problemsB.troubleC.painD.worry
小题4:
A.seatB.packageC.streetD.car
小题5:
A.sensibleB.interesting C.possibleD.moving
小题6:
A.carB.boxC.seatD.chair
小题7:
A.powerB.strengthC.handsD.arms
小题8:
A.mindB.airC.exerciseD.breath
小题9:
A.stuckB.takenC.shakenD.broken
小题10:
A.timesB.hoursC.momentsD.days
小题11:
A.alrightB.readyC.OKD.right
小题12:
A.bothB.allC.eachD.every
小题13:
A.stoppedB.keptC.pausedD.continued
小题14:
A.interestedB.excitedC.exhaustedD.surprised
小题15:
A.mostlyB.completelyC.nearlyD.greatly
单项选择题