Предмет: Физика, автор: nazarchik6878

Задача: Яка кількість речовини міститься в 14 кг Li?

Ответы

Автор ответа: pomagat0r3000
1

Відповідь:

Молярна маса літію (Li) становить близько 6,94 г/моль.

( А Молярна маса це маса одного моля речовини, виміряна в грамах. Якщо ми знаємо масу речовини в грамах, ми можемо визначити кількість речовини в молях, поділивши масу речовини на молярну масу.)

Перш за все, нам потрібно перетворити 14 кг літію в грами, множачи на 1000 (адже 1 кг = 1000 г). Таким чином, у нас є 14,000 г літію.

Потім, щоб знайти кількість речовини в молях, ми поділимо масу літію на молярну масу:

(14,000 г) / (6.94 г/моль) = приблизно 2017 моль.

Отже, в 14 кг літію міститься приблизно 2017 моль речовини.


VоЛk: для кисню ви теж будете писати 15,999 г/моль?
pomagat0r3000: Що ви маєте на увазі?
VоЛk: Молярна маса в шкільній програмі округлюється до цілого числа, окрім Хлора, щоб спростити задачі в рази
Автор ответа: 1Manka1
2
Дано:
m(Li)=14кг=14000г
Знайти:
n(Li)-?
Розв'язання:
n=m/M
M(Li)=7г/моль
n=m(Li)/M(Li)=14000/7=2000моль
Похожие вопросы
Предмет: Английский язык, автор: savinovaelizaveta
Present Perfect/Past Perfect
7
738
Прочитайте текст и ответьте на вопросы.
Jim lived with his parents until he was twenty-one years old, and then he got a job in the office of a big factory in another town,
so he left home. He found a comfortable little flat which had two rooms, a small kitchen and a bathroom, and he lived there on
his own.At first he cleaned it himself, but he did not want to have to go on doing this, so he determined to find someone else to
do it instead of him. He asked a lot of his fellow workers at the factory what they did about this, and at last one of the men said,
«Oh, Mrs. Roper comes and cleans my flat regularly. She washes the dishes, irons my shirts and keeps the place neat and tidy
and so on. I'll introduce you to her, if youlike. She's a charming old lady. She does her best, but she hasn't got much
energy.»«Well, you'd better ask her to come and see me, please,» Jim answered. So the next evening Mrs. Roper came to see
him, and she agreed with pleasure to come to his flat every morning for an hour.After she had been working for Jim for two
weeks, he looked at the mirror in his bedroom and thought, «That mirror looks very dusty. Mrs. Roper's forgotten to clean it. I
can write on it with my finger.» He wrote a message in the dust: «I'm coughing whenever I breathe because everything in this
room is very dusty » He came home at 7 o'clock that evening, and when he had eaten his supper, he went into his bedroom and
looked at the mirror. «That silly old woman still hasn't cleaned itl» he said to himself. «All it needs is a cloth!»But then he bent
down and saw a bottle in front of the mirror. «I didn't put that bottle there. He thought. «Mrs. Roper must have left it. He
picked the bottle up and looked at it carefully. «She's written some words on it, he said to himself. He read the words. They
were: «Cough medicine.
1. What kind of flat did Jim have?
2. How did Jim get to know Mrs. Roper?
3. How did Jim let Mrs. Roper know what he thought about her work?
4. What was Mrs. Roper's answer to him?