. K365 г 25 %-ному раствору хлористоводородной кислоты добавили
12.5 % -ный раствор NaOH до нейтрализации 1/5 части кислоты, ик
полученному раствору добавили 40 %-ный раствор Na2CO3 до тех пор,
пока в растворе соотношение количества вещества HCI и NaCI было
1:4. Определите процентную концентрацию поваренной соли В
растворе.
А) 11,7 B) 16,94 C) 20, 5 D) 26,5
какрй ответ
1.Anton Pavlovich Chekhov was a famous Russian playwright and physician.
3.Anton Chekhov was born on January 29th, 1860 in Taganrog, which is a port-city in south of Russia.
5.His mother was an excellent story-teller and a kind-hearted woman.
7.He also sang at his father’s choir at the Greek Orthodox monastery
9.Chekhov stayed in Taganrog to sell the family possessions and to finish his education.
11.After three years he joined his family in Moscow and (enter) a medical school there.
13.Before long, Chekhov discovered that he suffered from tuberculosis.
15.During one of such trips he met Leo Tolstoy and Maxim Gorky there..
17. Chekhov died on July 15th 1904.
2. They have been playing since breakfast time.
3. She has already doing her homework for two hours; but she has not yet done even half of it.
4. I have been waiting for you since two o'clock.
5. I have already read sixty pages.
6. This man is а writer. Нe writes books. He has been writing books since he was a young man. He has already written eight books.
7. Today she has been helping her mother since morning. They have already washed the floor and dusted the furniture.
8. Have you found your note-book?No,I am still looking for it.I have already looked for it,but haven't found it.
9. You have been playing with a ball for already three hours. Go home and do your homework.
10. Wake up! You have been sleeping for ten hours already.