Cho 23,9g hỗn hợp Na và Na2O hòa tan hết với nước tạo thành 5,6 lít khí hiđro (đktc). Tính phần trăm khối lượng mỗi chất trong hỗn hợp.

Các câu hỏi liên quan

1.​My home town ________________ (change) a lot in the recent years. 2.​Please, stop! You ________________(drive) so fast. 3.​The paintings ________________(make) on Dzo paper with natural colours. 4.​Yesterday I ________________(go) to the centre and ________________(see) an exhibition. 5.​As soon as I ________________(finish) painting my room, I’ll paint the kitchen. 6.​I ________________(be) to England three times so far. 7.​The children ________________ (not be) at home last Sunday. 8.​Do you think we ________________ (write) a test tomorrow? 9.​Are you interested in ________________(do) community service? 10.​Some teenage girls volunteered ________________ (work) at the local hospital. 11.​My house is very dirty. I ______________ (clean) it tomorrow. 12.​This coffee ______________ (taste) terrible, but the biscuits ______________ (be) great. 13.​Pho ______________ (become) more and more popular in Saigon since 1954. 14.​Last year we ______________ (go) on a school trip to Scotland. 15.​At the moment Joana ______________ (learn) to cook some Vietnamese dishes. 16.​I’m very sorry Dr. Jones ______________ (not be) back in the clinic until 2pm. 17.​The chicken meat served with pho ga ______________ (cut) into thin slices. 18.​My father ______________(eat) pho almost every morning at the restaurant nearby. 19.​The broth is made by ______________ (stew) cow bones for a long time. 20.​What is there ______________ (drink), Mike? 21.​Glastonbury festival _______________ (organise) every year in the village of Pilton, England. 22.​In 1076, King Ly Nhan Tong _______________ (build) the Imperial Academy as the first university of Vietnam. 23.​The first temples of My Son Sanctuary _______________ (make) of wood in the 4th century. 24.​An altar to Chu Van An _______________ (set) up in the Temple of Literature. 25.​We​_______________ (not do) any practice tests yet so I’m not sure what they’re like. 26.​Wait a minute, he _______________(speak) to someone on his mobile. 27.​Many different languages _______________ (speak) in Canada. 28.​The Imperial City of Hue can _______________ (divide) into two main parts. 29.​You’d better _______________ (rent) a bike if you want to travel around. 30.​I don’t want to go to Huong Pagoda. How about _______________ (visit) Ho Chi MinhMausoleum? II. Word form: 1. One Pillar Pagoda is a major tourist _______________ in Hanoi. (attract) 2.​Imperial citadel of Thang Long is a _______________ complex built during the Ly Dynasty. (culture) 3.​King Ly Nhan Tong was the _______________ of the Imperial Academy. (found) 4.​In 1484, King Le Thanh Tong odered the _______________ of the first Doctors’ stone tablets. (erect) 5.​The Imperial Academy was opened to educate _______________ students from all over the country. (talent) 6.​The circle and square of the pavilion _______________ the heaven and the earth. (symbol) 7.​The 82 Doctors’ stone tablets have recently received _______________ as a National Treasure. (recognise) 8.​Tourists like to visit _______________ monuments such as Ho Chi Minh Mausoleum and the Temple of Literature. (history) 9.​ Mike’s hobby is listening to music. He gets a lot ___________ from listening to music. (enjoy) 10.​John is a stamp ___________. He has a lot of rare and valuable stamps. (collect) 11.​One third of children in the U. S. is ___________ or obese. (weigh) 12.​I have ___________ so I must go to a dentist. (tooth) 13. Junk food is ___________, so we shouldn’t eat too much junk food. (health) 14. Blood ___________ give blood for use in hospitals. (donate) 15. They aren’t forced to do charity work. They do it ___________. (volunteer) 16. They opened a shelter to provide housing for the ___________. (home)