Đáp án:
\(\%m_{CaCO_3}=83,33\%\)
Giải thích các bước giải:
\(PTHH:CaCO_3+2HCl\to CaCl_2+H_2O+CO_2↑\\ n_{CO_2}=\dfrac{2,8}{22,4}=0,125\ mol.\\ Theo\ pt:\ n_{CaCO_3}=n_{CO_2}=0,125\ mol.\\ ⇒m_{CaCO_3}=0,125\times 100=12,5\ g.\\ ⇒\%m_{CaCO_3}=\dfrac{12,5}{15}\times 100\%=83,33\%\)
chúc bạn học tốt!
`CaCO_3` + 2`HCl → `CaCl_2` + `CO_2`↑ + `H_2``O`
$n_{CaCO_3}$bđ = `15/100` = 0,15 ( mol )
$n_{CO_2}$ = `2.8/22.4` = 0,125 ( mol )
mà $n_{CO_2}$ = $n_{CaCO_3}$pư = 0,125 mol
⇒ % $n_{CaCO_3}$ = `0.125/0.15` × 100% = 83,3%
v
Vẽ cho tui Ngụy Anh chibi trong Ma đạo vs
ke cho bo me nghe mot chuyen li thú mà em gap o truong không spam tren mạng
11. What ____________they (do)________________in the winter? 12. Today, we (have)______________English class. 13. Her favourite subject (be)__________________English. 14. Now, my brother (like)_________________eating bananas. 15. Look! A man (call)_________________you. 16. Keep silent ! I (listen )____________________to the radio. 17. ______________ you (play)_________________badminton now? 18. Everyday, my father (get up)_______________at 5.00 a.m. 19. Every morning, I (watch)_________________tv at 10.00. 20. Everyday, I (go) __________to school by bike. 21. Every morning, my father (have) ______________a cup of coffe. 22. At the moment, I(read)_______________a book and my brother (watch)_______ TV. 23. Hoa (live)________________in Hanoi, and Ha (live)________________in HCM City. 24. Hung and his friend (play)_______________badminton at the present. 25. They usually (get up)___________________at 6. oo in the morning. 26. Ha never (go)___________fishing in the winter but she always (do)________ it in the summer. 27. My teacher (tell)__________________Hoa about Math at the moment. 28. There (be)____________________ animals in the circus. 29. _______________he (watch)______________TV at 7.00 every morning? 30. What _____________she (do ) _________________at 7.00 am? 31. How old _________she (be)? 32. How ___________she (be)? 33. My children (Go)________________to school by bike. 34. We (go)_______________to supermarket to buy some food. 35. Mr. Hien (go)________________on business to Hanoi every month. 36. Ha (like)______________coffee very much, but I (not like)______________it. 37. She (like )________________Tea, but she (not like)____________________coffee. 38. I (love)_______________ cats, but I (not love)__________________dogs. 39. Everyday, I (go)______________to school on foot. 40. Who you _________________(wait) for Nam? - No, I ___________ (wait) for Mr. Hai. GIÚP CHÁU TÍP....
Một người đi xe đạp dự định đi từ A đến B dài 60 km trong một thời gian nhất định . Sau khi đi đc nửa quãng đường AB , anh ta nhận thấy vận tốc thực tế chỉ bằng 2/3 vận tốc dự định nên trên quãng đường còn lại anh đã tăng tốc thêm 3 km một giờ . Tuy vậy anh vẫn đến B chậm mất 40 phút . Hỏi vận tốc dự định của người đi xe đạp ?
Một người đàn ông mua một con ngựa với giá 60 đôla. Anh ta bán con ngựa với giá 70 đôla. Sau đó, anh ta mua lại con ngựa với giá 80 đô la. Và anh ta lại bán con ngựa với giá 90 đô la. Cuối cùng, người đàn ông đã kiếm được bao nhiêu tiền, lỗ hay là anh ấy hòa vốn? Đó mọi người giải đc nha!
Vẽ cho tui tranh Conan vs Haibara vs
cảm nghi về tình nhân ái qua dịch covid 19 giúp mình nha mn
Chia 60,8 g hh X gồm FeO ,Fe2O3, Fe3O4 thành 2 phần bằng nhau . Phần một cho tác dụng hết với dd HCl dư thì thu được 57,9 g muối khan , phần 2 cho tác dụng vừa đủ với dd hh chứa HCl ,H2SO4 loãng thì thu được 60,4 g hh muối khan . Tính mol HCl trong dd Y? LM CÁCH NÀO DỄ HIỂU NHẤT NHA CÁC BẠN!!! GIÚP MIK VSSSSSSSSSSSSS!
I My little brother, Carl, takes (53) ……………………………… our dad in that they both like to sing. The difference is that Dad’s got quite a good voice. Carl can’t sing at all! This doesn’t stop him, though. He’s always singing. He starts as soon as he wakes up, and doesn’t stop until he drops (54) ……………………………… at night. I usually get along very well (55) ……………………………… Carl, but he can be a bit annoying when he starts showing (56) ……………………………… You can count (57) ……………………………… him to do this whenever we have guests. My mum and dad will be talking to some friends, and then suddenly the conversation will be completely drowned (58) ……………………………… by Carl singing at the top of his lungs. The other day, I told him he should be on the radio. For a second he fell (59) ……………………………… it, until I told him that if he was on the radio, we could turn it off! II. Complete each second sentence using the word given, so that it has a similar meaning to the first sentence. Write between two and five words in each gap. 60. Was the concert fun? yourself Did …………………………………………………………………the concert? 61. I’m sure Kelly will do well in the talent contest. bound Kelly …………………………………………………………………well in the talent contest. 62. Don’t worry about your costume, concentrate on learning your lines! instead Concentrate on learning your lines …………………………………… about your costume! 63. We got there early and so we didn’t have to queue. avoid We managed to …………………………………………………………………there early. 64. Doug isn’t usually late. like It …………………………………………………………………be late. 65. Sean plays the guitar very well. talented Sean …………………………………………………………………the guitar. 66. You shouldn’t go backstage without a pass. supposed You …………………………………………………………………backstage without a pass. 67. I can’t understand why he won the award for best video. deserved I don’t think …………………………………..………………………the award for best video. 68. In the end, it was a thoroughly enjoyable evening. proved In the end, it …………………………………………………a thoroughly enjoyable evening. REALITY SHOWS IV Despite the (69) …………………………. (SUGGEST) by many critics that reality TV would be a very short-lived phenomenon, it is still increasing in (70) …………………………. (POPULAR). Several reality shows are (71) …………………………. CURRENT) watched by millions of viewers each night, and it’s clearly a form of (72) …………………………. (ENTERTAIN) that’s here to stay. Indeed, a number of people have become (73) …………………………. (FAME) because of their (74) …………………………. (INVOLVE) in reality TV shows, and have gone on to have successful careers as singers, (75) …………………………. (ACT) or TV presenters. We can watch with (76) …………………………. (EXCITE) each night the “goings-on” in the house (or jungle, or bar, or school of arts). The (77) …………………………. (CONVERSE) between the contestants are interesting so we don’t get (78) …………………………. (BORE), and there are frequently (79) …………………………. (VARY) conflicts, which provide further (80) …………………………. (AMUSE). If the contestants have to give some kind of (81) …………………………. (PERFORM) at the end of the week, that’s even more appealing. But there’s a (82) …………………………. (SAY) in the TV industry: “it’s all in the editing” and this is especially true of reality shows.
Một ô tô đi từ A đến B mất 5 giờ, nhưng khi từ B về A xe đi với vận tốc nhanh hơn lúc đi là 12km/h nên thời gian về chỉ mất 4 giờ . Tính vận tốc lúc đi của xe ô tô , biết rằng quãng đường lúc đi và lúc về như nhau.
Loga.vn - Cộng Đồng Luyện Thi Trực Tuyến