Câu 2: ở nhiệt độ thích hợp, hidro tác dụng được với chất nào sau đây?

1 điểm

A CaO

B CuO

C MgO

D Na2O

bạn ơi mik ko hiểu  cái phần này bạn gthik cho mik dc ko?

Bạn ơi tại sao lại lấy mC+mH=mX mà ko lấy mCO2+mH2O=mX

1. (attend) a. Mr Lee is not available at the moment. He ..................................... very important conference.

b. Before I decided which course to choose, I ..................................... quite a few introductory

meetings.

c. the Prime Minister promised he ..................................... the annual conference the following

year.

2. (take )a. My brother is an ice hockey lover. he ..................................... delight in playing it and watch it

on TV.

b. Elisabeth and I haven’t spoken to each other ever since she ..................................... offense

with me.

c. By next year, our company ..................................... on more than two hundred of new

employees for the new departments.

3. (complete) a. Now that you ..................................... the language course, you can take the First Certificate

exam.

b. From ten to eleven, the applicants ..................................... the forms. then, the interviews will

follow.

c. The writer ..................................... (not) his last novel before he died.

4. (investigate )a. A special police department ..................................... the crime from March till June last year,

but got nowhere.

b. The case of missing plutonium ..................................... by a special commission right now.

c. This detective is said ..................................... more than a hundred of such difficult cases so

far.

5. (refuse) a. ..................................... (you) to help us if we hadn’t paid you the money?

b. We still hope Mr Nelson will agree to represent us in court. He ..................................... (not)

our proposal yet.

c. If we don’t present any credible documents, the bank ..................................... to give us a

loan.

Một hỗn hợp gồm CH4 và H2 có thể tích 6,72 l , trong đó H2 chiếm 30% về khối lượng . Đốt cháy hòn toàn lượng hỗn hợp trên thì thu được bao nhiêu gam nước ?