Hi! My name is Jack. Visiting a river site is one of my most favourite things to do during the
summertime. The lakes I visited, was located about fifty kilometres away from my
hometown in the countryside. It was great! There were a number of restaurants and café. I
friends stayed at a hotel which was very close to the waterfalls. There were also
many beautiful mountains trees and waterfalls
I also walked on the sandy bank of the
river and i was surprised when my friends took a fish-rod for fishing. I swam every day.
Also we climbed the mountains It was a wonderful holiday.
and my
Задание1
1) 2HCI +Mg = MgCI2 + H2
4AL +3O2 =2AL2O3
2HgO = 2Hg + O2
K2O + H2O = 2KOH
2) замещение, присоединение, разложение, присоединение.
3) Реакциями соединения называются реакции, которые из двух веществ соединяются в одну. От сюда и пошло название - соединение.
Задание 2
1) 4AL+3O2=2AL2O3
2HgO=2Hg+O2
2) Это вещества, в состав которых входит один атом.
3) В реакциях соединения.
Задание 3
1) 2Zon + O2 = 2ZnO
S+ O2 = SO2
Na +O2 =NaO2
Cl + O2 = ClO2
4P + 5O2 = 2P2O5
2)Дано: Решение
m(Na2S)=15г x 0,19
m(Na2) - ? Na2 + S = Na2S
n=m/M
M(Na2S)= 78 г/моль
n(Na2S)=15г *поделить*78г/моль=0,19моль
x 0,19
- =
1 1
x=0,19 (Na2)
n(Na2)=0,19 моль
m=n*M
m(Na2)= 0,19моль *46г/моль = 8,74г
ответ: m(Na2) = 8,74 г.