K
Khách

Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.

6 tháng 9 2022

lưu ý đây ko phải là toán lớp 11

NV
7 tháng 9 2022

B đúng (Y là trường hợp riêng của X ứng với các giá trị n chẵn)

30 tháng 8 2022

Gọi kim loại cần tìm là R

$R + 2HCl \to RCl_2 + H_2$
Theo PTHH : $n_R = n_{H_2} = \dfrac{5,6}{22,4} = 0,25(mol)$
$M_R = \dfrac{10}{0,25} = 40$

Suy ra, kim loại cần tìm là Canxi

30 tháng 8 2022


HOẶC LÀ 
A + 2H2O --> A(OH)2 + H2
0,25                               0,25
nH2 = V/22,4 = 5,6/22,4 = 0,25 mol
MA = m/n = 10/0,25 = 40
=> A là Canxi

BÀI TẬP: ĐIỀN TỪ VÀO CHỖ TRỐNG        2.            The sun ……………. early in the summer.      3.            The students raise  ……………. in the class.      4.            He’s a  ……………. He works ……..a construction company. He builds house      5.            The ……………. type is friendly and likes helping or training other people.      6.            If you hurt...
Đọc tiếp

BÀI TẬP: ĐIỀN TỪ VÀO CHỖ TRỐNG

 

     2.            The sun ……………. early in the summer.

     3.            The students raise  ……………. in the class.

     4.            He’s a  ……………. He works ……..a construction company. He builds house

     5.            The ……………. type is friendly and likes helping or training other people.

     6.            If you hurt your hand on something that’s too hot, it’s helpful to put the ……………. under cold water. Then put some ointment on it.

     7.            Exercise ……………. the spirit and builds confidence.

     8.            Exercise ……………. you live longer.

     9.            The  ……………. type is practical and likes working with machines and tools

10.            I’m worried about ……………. on the streets.It’s a huge problem in this city. People just throw rubbish out of their car window.

11.            I’m worried about ……………. I think sea levels will rise and there will be lots of big floods.

12.            She’s a ……………. She works in a deparment store. She sells clothes

13.            For a toothache. It’s good idea to see the …………….

14.            The burning of …………….is one of the biggest sources of carborn monoxide (CO) in the atmosphere.

15.            He is a ……………. He works in a restaurant. He cooks …………….

16.            She is a …………….. She works for an airline. She serves passengers

17.            He is a receptionist . Hw works in an office. He answers the …………….

18.            I am worried about ……………. in the local river. There are hardly any fish in it now.

19.            I am worried about what will happen when we run out of …………….I don’t think anyone has found a solution to this problem yet

20.            Our environment is in …………… 

21.            In this the restaurant, I’m not in the mood for …………….

22.            Travelling by boat can be unpleasant if there are big ……………..

23.            For a sore throat, it’s a good idea to ……………. some vitamin C

24.            I’m worried about  ……………. in the local river. There are hardly any fish in it now.

 25.            It’s important to be able to read a …………… if  you don’t know the way somewhere.

 26.            Drivers have to stop when the  ……………. turn red.

 27.            ……………. lifts the spirit and builds confidence.

28.            For a sore throat, it’s a good idea to ……………. some vitamin C

 29.            She picked up a very big suitcase yesterday, and now she has a bad backache. She should see the  ……………. this morning.

1
29 tháng 8 2022

duive lên ik

8 tháng 9 2022

You can learn the difficult concept to understand from Solvemate. This is a education service for using technology to adapt in order to create mathematical problems based on the learning needs of students.
Math mate in your pocket. https://intro.solve-mate.com/

3 tháng 11 2022

x=30