Предмет: Химия, автор: Katrien11

У сільському господарстві для підживлення капусти використовують розчин калій хлориду. Обчисліть масову частку речовини, якщо відомо, що до 280 г 10% розчину додали 40 мл води. (відповідь у %)

Ответы

Автор ответа: dyexfnf

Ответ: 8,75%

Объяснение:

Дано:

m₁(р-ну) = 280 г

w₁(р.р) = 10% або 0,1

V(Н2О) = 40 мл

Найти: w₂(р.р) -?

1. Обчислимо масу розчиненої речовини, яка необхідна для виготовлення розчину

m(р.р) = m₁(р-ну) * w₁(р.р) = 280 * 0,1 = 28 г

2. Знайдемо масу води:

р(Н2О) = 1 г/мл

m(Н2О) = V(Н2О) * р(Н2О)=40 * 1 = 40г

3. Вичислимо масу розчину:

m₂(р-ну) = m₁(р-ну) + m(Н2О) = 280 + 40 = 320 г

4. Знайдемо масову частку розчиненої речовини в утвореному розчині:

w₂(р.р) = m(р.р)/m₂(р-ну) * 100% = 28/320 * 100% = 8,75%

Предыдущий вопрос

Следующий вопрос

Интересные вопросы

Предмет: Английский язык, автор: anutkagrabova

Complete the sentence with the vebs from the box. There is one extra words.
book, flat, right, mean, train
Did the telephone...?
He's swimming and he wants.... for the next Olympics.
Joe getting the ... to Glasgow .
What does it...?
He's very ... he never buys a drink.
She wears a gold...
They want to live in a ... near the centre.

1 год назад

Предмет: Алгебра, автор: face2face4ange

Подайте вираз у вигляді степеня (x³)⁷*x²

1 год назад

Предмет: История, автор: zvatrala

розкрити значення ВГВ

1 год назад

Предмет: Английский язык, автор: VIKA090597

ПОМОГИТЕ ПОЖАЛУЙСТА С АНГЛ
1. They had an argument last week. They are still not speaking to …
1) each other 2) their own 3) them 4) themselves
2. Don’t come at 10.30 tomorrow. I … the football match on television.
1)watch 2) will be watching 3) will watch 4) will have watched
3. Who … in this house many years ago?
1) did live 2) lived 3) lives 4) not lived
4. When she (come) home from school her sister (sleep).
1) came, slept 2) will come, will sleep 3) came, was sleeping 4) come, sleeps
5. I wonder (интересно) where she (buy) those things.
1) did buy 2) bought 3) does she buy 4) did bought
6. My bag … in the shop three days ago.
1) was stolen 2) had been stolen 3) stole 4) has been stolen
7. We are late. I expect the film … by the time we get to the cinema.
1) has already started 2) will already be starting 3) will already have started
4) already starts
8. Charlie said that he … Jack at the party a few months before.
1) saw 2) was seen 3) would see 4) had seen
9. Jim didn’t know about the change of plans. He …
1) didn’t tell 2) wasn’t told 3) hadn’t been told 4) hasn’t told
10. Last year I visited Spain. I … at a very nice hotel for two weeks.
1) had stayed 2) stayed 3) have stayed 4) had been staying
11. If he … soon, I’ll wait for him a little.
1) will come 2) came 3) comes 4) come
12. I am so worried. It is already late, and the children … yet.
1) don’t come 2) haven’t come 3) hadn’t come 4) haven’t been coming
13. Where …? To the University. Sorry, I can’t talk to you now.
1) are you hurrying 2) do you hurry 3) are you hurry 4) do you hurrying
14. I don’t want to ask him this question. I’m not sure if he… me a true answer.
1) gives 2) would give 3) gave 4) will give
15.They often … to the stadium.
1) goes 2) went 3) go 4) had gone

7 лет назад

Предмет: Математика, автор: albatara

СРОЧНО!!!! Отметь цифры, которые можно записать вместо ∗ , чтобы получилось верное неравенство: −∗38>−119 .

9
5
7
3
1
4
6
8
2

7 лет назад