【正文】
,Na2CO3和HCl(3)取濾液少量,加入BaCl2溶液,無(wú)沉淀產(chǎn)生,再滴入幾滴酚酞試液,溶液變紅色,—?jiǎng)t證明溶液中還有OH。取濾液少量,加入足量BaCl2溶液,有白色沉淀產(chǎn)生,再取上—層清液滴入酚酞試液,若溶液不變色,則證明溶液中還含有CO32。若溶液變?yōu)榧t色,——?jiǎng)t證明溶液中同時(shí)還有CO3OH39.(10分)(1)CaCO3+2HCl=CaCl2+H2O+CO2↑(2分)(2)吸水作干燥劑(1分)(3)吸收多余的二氧化碳(1分)(4)可通過(guò)控制加酸的量,控制產(chǎn)生氣體的快慢;同時(shí)小試管中充滿鹽酸,可達(dá)到液封—催化劑的作用。MnO2(5)①2H2O2═══2H2O+O2↑(2分)②在D、E之間增加一個(gè)裝有澄清石灰水的洗氣瓶,石灰水變渾濁,則說(shuō)明有二氧化碳生成;再在F出點(diǎn)燃?xì)怏w,若產(chǎn)生藍(lán)色火焰,且在火焰上方罩一內(nèi)壁涂有石灰水的燒杯,石灰水變渾濁,則證明有CO生成(2分)(5分)(1)如右圖(1分)解:(2)設(shè)混合物中Na2CO3的質(zhì)量為x,100g硫酸溶液中H2SO4的質(zhì)量為y。Na2CO3+ H2SO4 = Na2SO4+H2O+ CO2↑1069844x = y = -=(3)稀硫酸的溶質(zhì)質(zhì)量分?jǐn)?shù)為:100%=%答:略(1分)(1分)(1分)(1分)第四篇:初中畢業(yè)生學(xué)業(yè)考試初中畢業(yè)生學(xué)業(yè)考試一、選擇題。,則實(shí)數(shù)n的最大值是()A.178。6x+8=0的解是()178。+bx+c=0中的二次項(xiàng)系數(shù)與常數(shù)項(xiàng)之和等于一次項(xiàng)系數(shù),那么方程必有一根是()4.第五篇:貴陽(yáng)市2013年初中畢業(yè)生模學(xué)業(yè)考試英語(yǔ)聽(tīng)力材料貴陽(yáng)市2013年初中畢業(yè)生學(xué)業(yè)考試 英語(yǔ)聽(tīng)力材料 I、聽(tīng)力測(cè)試(本大題共30分,每小題1分)A 聽(tīng)對(duì)話,選擇與對(duì)話內(nèi)容相符的圖,并將答題卡上該選項(xiàng)涂黑。(讀一遍)’s wrong with you ,Mike?I have a does the sign mean?It means you can’t take photos , what does your teacher look like?She’s thin with long , can you play the piano?Yes, I can play it very , would you like something to drink?A cup of coffee, are you going on vacation, Betty?I’ll go to Beijing with my 聽(tīng)句子,選擇恰當(dāng)?shù)膽?yīng)答,并將答題卡上該選項(xiàng)涂黑。(讀一遍) color is the bag? you for your ’s go for a ’s the time, please? often do you exercise? C 聽(tīng)對(duì)話,根據(jù)對(duì)話內(nèi)容,選擇正確的選項(xiàng)完成句子,并將答題卡上該選項(xiàng)涂黑。(讀二遍): What do you think of the movie, Rose?W: It’s : Jim, are you ready to do some volunteer work?M: Yes, I’d like to help clean up the city : Alice, are you afraid of cats?W: I’m afraid of : Where are you going , Ted?M: I’m going to the train station to meet my : Hi, were you doing at 6:00 ?M: Oh, I was cooking dinner at : You look so happy today, Mary,W: got a letter from my pen 聽(tīng)對(duì)話及問(wèn)題,根據(jù)對(duì)話內(nèi)容選擇正確的答案,并將答題卡上該選項(xiàng)涂黑。(讀二遍): What’s your favorite subject ,Peter?B: : Why?B: Because it’s : Which subject does Peter like? : When is your birthday, Tina?B: On May the : How old are you, now?B: I’m : When is Tina’s birthday? : What’s your hobby , Jack?B: I like collecting : How many stamps do you have ?B: About : What does Jack collect? : What can I do for you, Madam?B: I’m looking for a : The red one is five : OK, I’ll take : How much is the red Tshirt? : Excuse me, is there a supermarket near here? B: Yes, there’s : Where is it ? B: It’s next to the : Where’s the supermarket? : Tom, what are you going to be when you grow up ?B: I’m going to be an : How are you going to do that ?B: I’m going to take acting : How is Tom going to be an actor? E 聽(tīng)短文及問(wèn)題,根據(jù)短文內(nèi)容選擇正確答案,并將答題卡上該選項(xiàng)涂黑。(讀三遍)I’m Molly from I’m studying in a ’m not happy every are too many rules I my parents always tell me, ”Don’t do that!You have to do this!” For example , I have to get up early and make my can’t listen to music when I’m breakfast, I have to take the bus to class because I can’t be so, my teachers will be weekends, I have to finish doing my homework before I watch must read books before I go to I have to be on bed at 10:00 ’s parents are so strict with makes me need more time to play and should I do ? Questions :’s Molly from? can’t Molly do when she’s eating? does Molly go to school? does Molly go to bed?’s strict with Molly? is Molly unhappy every day?