Cố gắng giải nhanh giúp mik nhé!
Mik cảm ơn.
Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
![](https://rs.olm.vn/images/avt/0.png?1311)
![](https://rs.olm.vn/images/avt/0.png?1311)
\(n_{Cu}=\dfrac{6.4}{64}=0.1\left(mol\right)\)
\(2Cu+O_2\underrightarrow{^{t^0}}2CuO\)
\(0.1....................0.1\)
\(m_{CuO\left(tt\right)}=0.1\cdot80=8\left(g\right)\)
\(H\%=\dfrac{m_{lt}}{m_{tt}}\cdot100\%=\dfrac{6.4}{8}\cdot100\%=80\%\)
![](https://rs.olm.vn/images/avt/0.png?1311)
Bạn ơi mk cx ko biết là mk nghi ngờ có đúng ko, but mk thấy đề bài của bạn sai sai sao á !! Bạn kiểm tra lại giúp mk nka !!
Giờ mk đưa ra 1 đề cx khá là giống vs đề của bạn . bạn xem rùi kiểm tra lại giúp mk ! còn nếu mk nghi ngờ sai thì cx thông cảm bỏ qua nka !!
\(Cmr:\)\(a^4+b^4\ge2ab\)
Ta có :
\(\left(a^4+b^4\right)^2\ge4a^2b^2\)( Cái này bạn chỉ cần khai triển ra, rồi chuyển vế để là có được hà )
\(\Leftrightarrow\left(a^4+b^4\right)^2\ge\left(2ab\right)^2\)
\(\Leftrightarrow a^4+b^4\ge2ab\left(dpcm\right)\)
Ney61 thấy đúng thì nka !! CHÚC BẠN HỌC TỐT
@ nguyễn kim thương
bạn thử a,b cung dấu khác 0 và thuôc (-1,1) xem đúng không vậy? VD: a=b=1/2
![](https://rs.olm.vn/images/avt/0.png?1311)
PTHH: \(2KClO_3\rightarrow2KCl+3O_2\)
\(1\rightarrow1,5\left(mol\right)\)
Theo phương trình: \(n_{O_2lt}=\dfrac{1.3}{2}=1,5\left(mol\right)\)
Khối lượng \(O_2\) thu được theo lý thuyết là :
\(m_{O_2lt}=1,5.32=48\left(g\right)\)
Hiệu suất phản ứng là:
\(H=\dfrac{43,2}{44}.100\%=90\%\)
![](https://rs.olm.vn/images/avt/0.png?1311)
nAl=10/27(mol)
ta ccó pthh: 2Al+3S->Al2S3( nhiệt dộ cao)
theo ptth=> nAl2S3(lý thuyết)=1/2.nAl=\(\dfrac{1}{2}.\dfrac{10}{27}\)=\(\dfrac{5}{27}\)(mol)
=> mAl2S3(lý thuyết)=\(\dfrac{5}{27}.150=\dfrac{250}{9}\)(g)
=>H=\(\dfrac{mAL2S3\left(thucte\right)}{mAL2S3\left(lythuyet\right)}.100\%=\dfrac{25,5}{\dfrac{250}{9}}=91,8\%\)
![](https://rs.olm.vn/images/avt/0.png?1311)
![](https://rs.olm.vn/images/avt/0.png?1311)
Để giải phương trình \( y:(\frac{1}{2} \times 4+\frac{1}{4} \times 6+\frac{1}{6} \times 8+\frac{1}{8} \times 10) \times y=\frac{1}{3} \), ta có thể làm như sau:
Đầu tiên, tính giá trị của phần tử ngoặc đơn trong phương trình:
\( \frac{1}{2} \times 4+\frac{1}{4} \times 6+\frac{1}{6} \times 8+\frac{1}{8} \times 10 \).
\( = \frac{2}{2} \times 4+\frac{1}{2} \times 6+\frac{1}{3} \times 8+\frac{1}{4} \times 10 \).
\( = 2+3+\frac{8}{3}+\frac{10}{4} \).
\( = 2+3+\frac{8}{3}+2.5 \).
\( = 5+2.667+2.5 \).
\( = 10.167 \).
Tiếp theo, thay giá trị tính được vào phương trình:
\( y \times 10.167 = \frac{1}{3} \).
Để tìm giá trị của y, ta chia cả hai vế của phương trình cho 10.167:
\( y = \frac{\frac{1}{3}}{10.167} \).
Tiếp tục tính toán:
\( y = \frac{1}{3} \times \frac{1}{10.167} \).
\( y \approx 0.030 \).
Vậy giá trị của y là khoảng 0.030.
[1/(2 × 4) + 1/(4 × 6) + 1/(6 × 8) + 1/(8 × 10)] × y = 1/3
(1/2 - 1/4 + 1/4 - 1/6 + 1/6 - 1/8 + 1/8 - 1/10) × y = 1/3
(1/2 - 1/10) × y = 1/3
2/5 × y = 1/3
y = 1/3 : 2/5
y = 5/6
![](https://rs.olm.vn/images/avt/0.png?1311)
Refer:
My house has a lot of room like living room, kitchen, dinning room, etc. But, L love my bedroom the most. It's on the second floor in my house. In this room, there is a bed where I often sleep well every night. It is beautiful and it's made from wood. Next to my bed is my big desk where I learn and do exercise every day. On the desk, there are my books and notebooks to study at school and at extra classes. Besides, there is a large wooden bookshelf next to my desk. It help me relax and search information. Also, there is a wooden wardrobe in my room which has a lot of clothes. Those are everything in my bedroom. I love it a lot because it's a place where I always relax after a hard studyng-day. Beside, I have got a lot of sweet memories in this room like the happy memory about my sleeping party with my classmates. In conclusion, it is clear that my favourite room in my house is my bedroom.
My house is not very big; therefore all of the rooms also have a small size. My bedroom is on the second floor, and there are not many things in it. I choose a light grey color for my room to make it look clean. In the corner of the room is my bed; right on the wall next to it is a small window with white curtain. On the opposite corner is a table which I use to sit and study, and above the table is a bookshelf where I put my textbooks, novels, and comics that I like to read. On the right of the bed is a big wardrobe where I store all of my clothes and other things, and it also has a big mirror on it so I can get dress easily. Next to the wardrobe is a small bathroom, so it is very convenient for me to go to the toilet at night. My room is just that simple, but I love it very much.