Предмет: Химия, автор: lymalololoMari

При выпаривание 25г р-ва получили 0,25 г соли , Определите массовую долю растворённого вещества и выразите ее в процентах

Ответы

Автор ответа: Виктория0503

w = m(в-ва)/m(р-ра)*100%
w = 0.25/25*100% = 1%

Предыдущий вопрос

Следующий вопрос

Похожие вопросы

Предмет: Информатика, автор: ratislavt27092000

какая проблема возникает при использовании симметричного шифра , если участники переписки находятся в разных странах

5 лет назад

Предмет: Қазақ тiлi, автор: puzanovan376

Помогите пж пж пж пж пж пж пж

5 лет назад

Предмет: Английский язык, автор: jate65

Final test. 7th form. V-11
Task 1. Choose the correct item:
1. Sportsmen have to train hard
a) hardly b) hard
2. Have you been toge Museum of Modern Art in New York? a) the, b) the the, the
3. A nurse's job isn't as a firefighter's a) more dangerous b) as dangerous c) the most dangerous
They look forward to us on Christmas.
a) visit b) to visite) visiting
You'd better
me home
a) taking b) take c) to take
011
If the chemist's open, I would have bought some aspirin. a) was b) had been c) is
If she tickets, we will go to the stadium.
a) will buy b) buy c) bought
8. If you mix red and white, you
pink.
a) get b) got
c) will get
9. If I were you, these jeans
a) don't wear b) won't wear c) wouldn't wear
10. We switch our mobile phones off in class.
a) have to b) must
c) can
11. You go into the garden - it's private property. a) might not b) don't have to c) mustn't
12. Sam
in the garden while I was cooking dinner. a) worked b) was working c) will work
13. He used to to the Opera when he was young.
a) goes b) go
c) went
14. They weren't allowed the class.
a) to enter b) entering e) enter
15. People let him
a) speaking b) speak e) to speak
Task 2. Open the brackets:
1.1
(travel) to London next Sunday. The train is in the morning,
2.1
(practise) yoga and meditations regularly.
3. He
(go) for a walk before she arrived.
4. At 9 o'clock last night, I
(write) emails
3
they (leave) the cinema an hour ago?
6. Mfike
(study) abroad for some years.
7. The band
(become) popular recently.
8. She (live) in New York for ten years before she moved to London.
9. I hope we (go) on a hike tomorrow.
10. The film
(start) at 7.00 p.m. tomorrow.
Task 3. Write the sentences in the Passive:
1. The trees (plant) recently.
2. The books (sell) yesterday.
3. The children
(teach) now.
4. His essay (read) next Saturday.
5. Letters (usually send) by post.
V. Report the sentences:
1. “I will buy you a new guitar," mother said to me.
2. They said: "He is coming to see us soon."
3. "Our team won the tournament last year," said the man.
4. "Where are you going tomorrow?" asked my Granny.
5. "Come home as soon as possible” said Mom.

5 лет назад

Предмет: Химия, автор: anyagerasimenk

Сокращенное ионное уравнение N₂O₅+2OH⁻ →2NO₃⁻+H₂O соответствует реакции:
1) HNO₃+NaOH →NaNO₃+H₂O
2)N₂O₅+NaOH →2NaNO₃+H₂O
3)N₂O₅+Cu(OH)₂ →Cu(NO₃)₂+H₂O
4)2HNO₃+Cu(OH)₂ →Cu(NO₃)₂+2H₂O

9 лет назад

Предмет: Математика, автор: faxxa83

В ведре 8 л воды,а в кастрюле в 4 раза меньше.Сколько литров воды в двух таких кастрюлях?

9 лет назад