Mg + 2НСl = MgCl2 + H2,
2Al + 6НСl = 2АlСl3 + 3Н2.
Пусть в 0,39 г сплава содержится х моль Mg и у моль Al, тогда
m(сплава) = 24х + 27у = 0,39 г
Количество выделившегося водорода равно
ν(Н2) = х + 1,5у.
По условию задачи выделилось
ν(Н2) = х + 1,5у = 0,448 л/ 22,4 л / моль = 0,02 моль.
Решая систему, получаем
х = 0,005 моль – ν(Mg), у = 0,01 моль – ν(Al).
Массы магния и алюминия в 0,39 г сплава равны:
m(Mg) = 24 г/моль · 0,005 моль = 0,12 г;
m(Al) = 27 г/моль · 0,01 моль = 0,27 г.
Массовые доли компонентов сплава рассчитываем по формуле:
ω=m(металла)⋅100%/m(сплава)
ω(Mg) = 0,12 г ⋅100%/0,39 г= 30,8%;
ω(Al) =0,27 г ⋅100%/0,39 г= 69,2%.
I am 15year old girl and I have very strict parents.They don't like it when I go out to meet my friends.They know very well that I am a responsible child but they are always so overprotective.I love them but they kill my social life.I never have freedom.I always have to be there when they call me.I let my friends down.I don’t go to their birthday parties or to the cinema.I’m also afraid of losing them,I feel depressed and stupid over it.I can’t wait until I’m 18nto do what I want to.Please help.
What’s Ann’s problem?-She has strict parents.
What should Ann do?-She should wait for her 18th birthday.She should to her parents about her social life.
