Cho 2.14 (g) NH₄Cl vào cốc chứa 300ml dung dịch B . Đun sôi sau đó để nguội rồi thêm ít quỳ tím vào cốc. Qùy tím có đổi màu không? tại sao?

Tính nồng độ mol các ion Al³⁺,SO₄^2-trong dung dịch Al₂(SO₄)₃ 25% (D = 1,386g/ml)?

Some people say that cell phones have improved modern life. Othes believe that cell phones have caused many problems to people. What is your opinion? In about 120-150 words write an essay to asert your point of view on this issue?

_Các cậu giúp mình với ạ_

1. You'd feel better ì you had a quiet holiday.(DO)

2. By change I was in that town when the earthquake started.(HAPPEN)

3. Despite knowing this place very well, I got lost.(THOUGH)

4. Were Jack not so affluent a man, she would not be dating with him.(BUT)

5. They listened eagerly and attentively to the President's speech.(EARS)

_Mọi người giúp em với ạ_

x+ 600 = 300 + 700 

=> x+ 600 = 1000 

=> x= 400 

đáp số x= 400