Ngâm 1 miếng chì có kluong là 286g vào 400ml dd đồng (II) clorua. Sau t/gian thấy khối lượng chì giảm 10%

a/ tính kl chì pứ và khl đồng sih ra

b/ CM dd CuCl2

c/CM của dd muối chì sinh ra

Hòa tan 20.4g oxit kim loại hóa trị II vào 300ml dd H2SO2 4M. Spứ thu đc 68.4g muối khan:

a/ tìm công thức oxit

b/ CM chất tan trong dd sau pứ

Các bn giúp mình với nha!

1. know---> known

2.times--> time

3.would--> will

4. where is located---> which is located

1. the course begins ........on...........2 January, and ends sometimes ........in.......April

2 the children aren't here at the moment, but they'll be back ....in............... a few minutes

3. we're having a party ....on..........New year's Eve. Can you come ? I'm afraid I can't. I don't like going out .......at........night

4. shall we go now? no, let's wait .......untill.............it stops raining

5. i've got an interview next week. it's ..........at..........9.30......in............tuesday morning

6. bill has worked in this company.....for....five years......since........he graduated from Boston University

7. it rained......in....... the night ......for...... two or three hours

1. These shirts were expensive so she couldn't buy them

2. A new school has been built in this city

3. The date of the meeting has to be changed

4. Hoa finished her work late, because she didn't have time

5. She used to wear the ao dai last year

6. He buys this book because it is cheap

1. C. Carefully

2.B. Were

3.A. Doesn't come

4.C. Although

5.C. Happily

6.B. Having

7.D. which