Осуществить химические превращения по следующей цепочке:

CuO → CuSO4 → Cu(OH)2 → CuO → Cu

Вычислите массу оксида меди (ll),который может прореагировать с 73 г 20%-ного раствора соляной кислоты.

C раствором сульфата меди(ll) реагируют:

1)Cuo

2)SiO2

3)Fe

4)AlCl3

выбирите правильный ответ

1.Their family has been living in this house since the 18-th century...?

A-haven't they

B-hasn't it

C-don't they

D-isn't it

2.They promised that they...at nine o'clock.

A-will come

B-came

C-would come

D-would came 

 3.I didn't know where...

A-the children had gone

B-the children went

C-had the children gone

D-did the children go

4.Catherine said that she...to buy an ice-cream.

A-had wanted

B-want

C-wants

D-wanted

5.Sally was happy because he...the first prize

A-has won

B-won

C-had won

D-win

6.Show me the picture of Helen.I...her

A-had never seen

B-didn't ever seen

C-have never seen

D-never saw

7.After Philip...his brother to prison, he...a king

A-sent,became

B-had sent, became

C-sent,had become

D-had sent, had become