Đáp án:
nC2H5OH = 0,05 mol; nCH3COOH = 0,05 mol
CH3COOH + C2H5OH → CH3COOC2H5 + H2O (đk nhiệt độ, H2)
Khối lượng CH3COOC2H5 = 0,05 x 88 = 4,4 gam.
Giải thích các bước giải:
Đáp án: 4,4
phân tích đa thức thành nhân tử
Complete the sentences with the correct form of be able to or have to and the verb given. 1. "You must invite cousin Jane to your party." "……………………………………… (I / have to ask) her? She's much younger than the other kids who will be there." 2. Students ……………………………………… (have to do) a lot of homework. This sometimes means that they ……………………………………… (not be able to spend) much time on hobbies. 3. Olga is starting college in London next October. She ……………………………………… (not have to look for) a flat as her sister is studying there and Olga ……………………………………… (be able to live) with her. 4. "I went to the U2 concert last week. My dad ……………………………………… (be able to get) tickets." "……………………………………… (he / have to pay) a lot for them?" 5. We …………………………………… (not be able to find) a room in a hotel so we ………………………………… (have to stay) at a small guesthouse on the island. 6. "……………………………………… (you / be able to babysit) for us on Saturday night?" "Yes, but I ……………………………………… (have to be) home by midnight." Your friend is having a party and wants some help planning it. Give your friend some advice. Use should / ought to / must / have to / need, positive or negative. 1. It’s important that the music is good so you ………………………… hire a DJ. 2. You ………………………… spend a lot on food, as nobody eats much at parties. 3. You ……………………… have the party on a week day because we'll Have to get up early for school the next day. 4. You ………………………… give out the invitations soon. Don't wait till the last minute as people might have other plans. 5. You ………………………… buy new clothes to wear at the party - you’ve got lots of cool things to wear. 6. you ………………………… make much noise as it will keep your neighbours awake.
I.Arrange these words to make meaningful sentnces 1.you/have/finished /homework/your/yet ? 2.printer/under/this/guarantee/is 3.vacation/since/we/haven't/last/had/a/year. 4.Hanoi/homeless/give/in/clothes/away/they/warm/to/people 5/our/a/in/makes/volunteering/difference/community II give the correct form of the verbs in brackets 1.How many times (you/be)..........................to the cinema this month ? 2.How many times (she/go)........................... to the cinema last moth? 3.(you/ever/be)....................to Rusia? 4.(you/go).................. to Moscow when you were in Russia ? 5.(he /do)............his homework yet? 6.No ,he still(not/finish)......................it 7.(you/play)..............football when you were younger ? 8. (ever/you/play)..................... baseball ? 9.My life has been very sad because I (not/ever ?be)............................in love . 10.How (spend/you/usually)........................... your weekend when you (be) ...........a child ?
Giúp mik b1 nha Mik sẽ vote 5 sao
Tính giá trị biểu thức : A = $3^{2}$. $3^{3}$ + $2^{3}$. $2^{2}$ B = $3.4^{2}$ - $2^{2}$.$3$ C = $2^{10}$$-$ $2$ D = ($2^{9}$.$3$ + $2^{9}$.$5$) - $2^{12}$
Tìm giá trị lớn nhất của biểu thức P=(1- √x ) / (√X) + 2
vẽ cho mình 1 bức tranh có cô gái đang lướt ván bay trên vũ trụ cùng với 2 con robot trên trời ít nhất có 3 hành tinh không có chữ kí thay vào đó là chữ PA được khắc nên bức tranh phải vẽ bằng bút bi đen có màu, tô đen trắng cũng được vẽ trên giấy ko vẽ bằng app
5 bạn A, B, C, D, E mỗi người vẽ 4 đường thẳng và đếm số giao điểm của các đường thẳng đó. Biết : A đếm được 2 giao điểm B đếm được 3 giao điểm C đếm được 5 giao điểm D đếm được 6 giao điểm E đếm được 7 giao điểm. Chứng minh rằng một người trong số họ đã sai.
Complete the dialogues with the modals below. 1. can - will - needn't Ellen: Is anything wrong? You don't seem very happy. Mary: I'm worried about tomorrow's English exam. I think it……………………… be difficult. Ellen: But you ……………………… worry about that. You're really good at English! Mary: Well, I know that I ……………………… speak it well but I'm not that good at writing compositions. 2. can't - won't - shall - will - ought to Thomas: ……………………… we go to the cafe? James: I don't really want to. I've got toothache and I ……………………… eat anything. Thomas: You ……………………… go to the dentist's. It ……………………… get better on its own. James: I know. It's just that I'm a bit scared. ……………………… you come with me? 3. might - can - should - can't Sister: There's someone at the door. Brother: Go and answer it then. Sister: But I don't know who it is and it's dark outside. It ……………………… be a burglar. Brother: It ……………………… be a burglar, silly! They don't ring doorbells. Sister: I suppose you're right. But ……………………… you answer it, please? Just in case. Brother: Okay. Anyway, it's probably Paul. He ……………………… be here soon. 4. should - could - mustn't - will Boy: ……………………… you help me? I want to go to the zoo. ……………………… I take the number 12 bus? Woman: No, you ……………………… take the number 12. It doesn't go to the zoo. Take the number 21. Boy: Does it stop right outside the zoo? Woman: No, but the driver ……………………… tell you where to get off. Boy: Thanks.
Tìm x (Có giải thích với ạ) 5^x+1 + 6.5^x+1 = 875
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