Chiều rộng HCN là:                                       18:2=9(cm)

Diện tích HCN là :                                      18x9= 162(cm2)

                                                       Đáp số: 162cm2

Cậu tick cho mình nhé!

\(n_{Al_2O_3\left(bd\right)}=\dfrac{1\cdot10^6}{102}=\dfrac{500000}{51}\left(mol\right)\\ n_{Al_2O_3\left(pu\right)}=\dfrac{500000}{51}\cdot\dfrac{90\%}{100\%}=\dfrac{150000}{17}\left(mol\right)\)

Bảo toàn nguyên tố Al ta có:

\(n_{Al\left(sinhra\right)}=n_{Al\left(Al_2O_3pu\right)}=\dfrac{150000}{17}\cdot2=\dfrac{300000}{17}\left(mol\right)\\ \Rightarrow m_{Al\left(sinhra\right)}=\dfrac{300000}{17}\cdot27\approx476470,59\left(g\right)\approx0,47647\left(tan\right)\)

\(n_{O_2\left(tt\right)}=\dfrac{40000}{32}=1250\left(mol\right)\)

\(\Rightarrow n_{o_2\left(PTHH\right)}=\dfrac{1250\cdot100\%}{85\%}=\dfrac{25000}{17}\left(mol\right)\\ 2H_2O\underrightarrow{dp}2H_2+O_2\)

Theo PTHH => nH2O=2nO2=2*25000/17(mol)

\(m_{H_2O\left(can\right)}=\dfrac{25000}{17}\cdot2\cdot18\approx52941,18\left(g\right)\)

Trên tia đối của tia MA lấy điểm D sao cho AM = MD

Xét tam giác BMA và CMD, có:

BM = MC (gt)

AM = MD (gt)

BMA = DMC (đ đ)

=> BMA = CMD (cgc)

=> AB = DC và góc ABM = MCD 

=> AB // CD => BAC + DCA = 180 mà BAC = 90 => DCA = 90

Xét tam giác ABC và tam giác CDA, có:

AB =CD

BAC = ACD

AC chung

=> tam giác ABC = CDA (c.g.c)

=> BC = AD

Mà AM = 1/2 AD (gt)  => AM = 1/2 BC Hay AM = MB = MC = BC/2 

Đây là tính chất đường trung tuyến ứng với cạnh huyền trong tam giác vuông nhé. có thể chứng minh chiều ngược lại (cho AM = BC/2 => tam giác ABC vuông tại A)

\(n_{Al}=0,1\left(mol\right)\\ n_{CO_2}=1,5\left(mol\right)\\ 4Al+3CO_2\underrightarrow{t^o}2Al_2O_3+3C\)

n(bd) 0,1 1,5

n(spu) 0 1,425

\(2Mg+CO_2\underrightarrow{t^o}2MgO+C\)

2,85 1,425

\(m_{hh}=2,7+24\cdot2,85=71,1\left(g\right)\\ \Rightarrow\%m_{Al}=\dfrac{2,7\cdot100\%}{71,1}\approx3,797\%\\ \Rightarrow\%m_{Mg}=100\%-3,797\%=96,203\%\)

bạn viết đề bài hơi rồi nên mk làm theo cách mk hiểu, ban kiểm tra lại thể tích CO2 xem có phải là 3,36 l khong vi mk thay so mol CO2 hoi lon

1.This dish is brought to me by the waiter

2.These postcards are sent by our friends.

3.This story was told by their grandmother when they visited her last week.

4.This train ticket was ordered by Tim for his mother.

5.The special cameras weren't showed to me.

6.Her ticket was showed to the airline agent

7. His new shoes are lent to his friends.

8.5million pounds were left to her relatives

9.These boxes were handed to the customers.

10.The first prize was awarded to the reporter.

11.

12.Alice secretary wa appointed for the meeting

13.The broken cup is hided in the drawer.

14.This room is kept tidy all day

15.The party was voted to a greastest sucess

16.Some bananas and some flowers were given to Ann

17. The fridge was moved into the living room

18. Some cups of tea were bought to the visitors in the nest room

19. The new project is found to be worthless

20. the note wasn't taken to the manager.

Bạn kiểm tra lại đi chắc có sai sót gì đấy

ý b mk nhớ là luôn thỏa mãn