Предмет: Химия, автор: vikaakop00

При растворении карбоната кальция в избытке азотной кислоты выделяется 5,6л (н.у) газа.Масса карбоната кальция равна ___г

Ответы

Автор ответа: angelinavostrekova

Ответ:

дано

V(CO2) = 5.6 L

---------------------------

m(CaCO3)-?

CaCO3 + 2HNO3-->Ca(NO3)2+H2O+CO2

n(CO2) = V(CO2) / Vm = 5.6 / 22.4 = 0.25 mol

n(CaCO3) = n(CO2) = 0.25 mol

M(CaCO3) = 100 g/mol

m(CaCO3) = n*M = 0.25 * 100 = 25 g

ответ 25 г

Предыдущий вопрос

Следующий вопрос

Похожие вопросы

Предмет: Русский язык, автор: younotlucker

Образуйте степени сравнения от следующих наречий:Сильно.рано.хорошо

1 год назад

Предмет: Английский язык, автор: nastyay1808

помогите пожалуйста, напишите сочинение на тему " Как я мечтаю провести один день"

1 год назад

Предмет: Английский язык, автор: YanaSavenkova

Помогите пожалуйста!

1 год назад

Предмет: Математика, автор: igorgudets79

Помогите решить :
х-3/4х=2

7 лет назад

Предмет: Английский язык, автор: Alina0506

1. Fun in theory, boring in reality 5. Similar sounds – different emotions
2. Saving rare animals 6. Benefits of being outdoors
3. Deficit of activity problems 7. Contrary to popular belief
4. Ready to help 8. Original style
A. In addition to being highly intelligent, elephants are capable of a remarkable
amount of empathy. During a natural disaster, elephants are able to understand
that something dangerous is happening. They can understand that a person is in
trouble and that the situation is unsafe. Elephants have good sense of smell and
there have been cases when they alerted rescuers to people trapped in a
building. Elephants have been observed saving their young from drowning and
also been filmed trying to save people they see at risk of drowning.
B. A lot of studies suggest that green spaces enhance mental health and learning
capacity, both immediately and over time, by lowering stress levels and
restoring attention. Greenery restores attention by drawing the eye and at the
same time calms the nervous system, creating an ideal state for learning.
Similarly, studies show that spending time in the sunlight can reduce attention
deficit symptoms, while bright light first thing in the morning can improve
mood and the quality of sleep.
C. Why are hyenas known for laughing? There is even a phrase we use: “to laugh
like a hyena”. Zoologists will tell you that the unique sounds they make are
actually no laughing matter. Hyenas indeed make loud barking noises that
sound like laughter, but it’s not because they’re amused by anything. Instead, a
hyena’s “laughter” is actually a form of communication used to convey
frustration, excitement, or fear. Most often, you’ll hear this unique vocalization
during a hunt or when the animals are feeding on prey as a group.
D. Zoologists believe that boredom isn’t a uniquely human emotion – animals can
be bored, too. Animals which live in captivity (in zoos, for example) and don’t
have to take care of their survival may experience boredom and try to find
ways to overcome it. They may come up with some “creative” activities which
they wouldn’t normally do in their natural environment. As for the pets at
home, they may also suffer from the lack of stimulation. That’s why we need to
make sure we give them enough time, attention and toys regularly.
E. While most dogs jump eagerly into the water to swim, cats don’t usually do
that, and many believe that cats have a phobia of water. But some pet groomers
insist that it’s not true and getting a cat to trust you enough to bathe is quite
possible, with some patience and skill. Most cats are not afraid of water like so
many people may think. They are actually afraid of loud noises and of
drowning, rather than water itself. Cats drink water every day, lots of cats even
play with water or follow people into the shower.
F. Videogame testers spend most of their time testing the game long before it’s
finished and long before it starts to become a fun experience. Even after the
game is developed enough to start being fun, the testing tasks often aren’t
entertaining at all. Testers may have to walk their character around a forest, for
example, to look for trees that aren’t drawn well. They then record the
coordinates so an artist can fix them later. It’s monotonous work and can take
days to finish. So if testing video games seems like a fun, easy job to you, think
again.
G. Claude Monet’s impressionist paintings were all about nature. In his works he
tried to capture nature as it appeared to him at the moment. He also
experimented with light and shadow and how they changed during different
times of the day. Some artists of the time criticized Monet because his works
lacked detail and didn’t resemble finished paintings. Monet used strong
colours, which he did not mix. He painted them onto the canvas in short brush
strokes. He was also criticized for not using classical painting techniques.

7 лет назад