2 г 2,8 л Х г Ba(OH)2 + CO2 = BaCO3 ↓ + H2O 171 г 22,4 л 197 г Найдем массу и объём веществ по уравнению: m = M x n m(Ba(OH)2) = 171 г/моль х 1 моль = 171 г m(BaCO3) = 197 г/моль х 1 моль = 197 г V = Vm x n V(CO2) = 22,4 л/моль х 1 моль = 22,4 л Найдем массу Ba(OH)2 в смеси: ω = m(в-ва) x 100% / m(смеси) m(в-ва) = ω х m(смеси) / 100% m(Ba(OH)2) = 10% х 20 г / 100% = 2 г Для того чтобы найти массу осадка нужно выяснить какое из реагентов взято в недостатке, по нему и делать расчет. Возьмем массу гидроксида бария за Х, тогда: Х г / 171 г = 2,8 л / 22,4 л m(Ba(OH)2) = 2,8 л х 171 г / 22,4 л = 21,375 г, значит он взят в недостатке, потому что по условию задачи его 2 г, Найдем массу осадка: 2 г / 171 г = Х г / 197 г m(BaCO3) = 2 г х 197 г / 171 г = 2,3 г
Dear Barbara, Thank you for your letter. It was so nice to hear from you. I hope your trip was wonderful.
I also traveled a lot this summer. In August, Elena and I were abroad. We spent two weeks in Scotland in the summer school. We lived and studied in a good public school. Would you like to know what is there?
Well,in the morning we spent 3 hours learning English. In class we read and discussed texts, learned poems by heart in English, played , asked questions, learn new words used in the computer and wrote their own stories. But we did not do the translation in Russia, on our the lesson because we are not done, they speak Russian. We also learned about English history and traditions.
Now we speak and read English much better, we did it last year . I have made many friends in Scotland. We also spent 3 days in London. I tried to call you but you were not available. Our impression of the UK and hope to visit it again. Best wishes from all of us. Your "lazy children." Elena and Olga.
Dear Barbara, Thank you for your letter. It was so nice to hear from you. I hope your trip was wonderful.
I also traveled a lot this summer. In August, Elena and I were abroad. We spent two weeks in Scotland in the summer school. We lived and studied in a good public school. Would you like to know what is there?
Well,in the morning we spent 3 hours learning English. In class we read and discussed texts, learned poems by heart in English, played , asked questions, learn new words used in the computer and wrote their own stories. But we did not do the translation in Russia, on our the lesson because we are not done, they speak Russian. We also learned about English history and traditions.
Now we speak and read English much better, we did it last year . I have made many friends in Scotland. We also spent 3 days in London. I tried to call you but you were not available. Our impression of the UK and hope to visit it again. Best wishes from all of us. Your "lazy children." Elena and Olga.
Ba(OH)2 + CO2 = BaCO3 ↓ + H2O
171 г 22,4 л 197 г
Найдем массу и объём веществ по уравнению:
m = M x n
m(Ba(OH)2) = 171 г/моль х 1 моль = 171 г
m(BaCO3) = 197 г/моль х 1 моль = 197 г
V = Vm x n
V(CO2) = 22,4 л/моль х 1 моль = 22,4 л
Найдем массу Ba(OH)2 в смеси:
ω = m(в-ва) x 100% / m(смеси)
m(в-ва) = ω х m(смеси) / 100%
m(Ba(OH)2) = 10% х 20 г / 100% = 2 г
Для того чтобы найти массу осадка нужно выяснить какое из реагентов взято в недостатке, по нему и делать расчет. Возьмем массу гидроксида бария за Х, тогда:
Х г / 171 г = 2,8 л / 22,4 л
m(Ba(OH)2) = 2,8 л х 171 г / 22,4 л = 21,375 г, значит он взят в недостатке, потому что по условию задачи его 2 г,
Найдем массу осадка:
2 г / 171 г = Х г / 197 г
m(BaCO3) = 2 г х 197 г / 171 г = 2,3 г