Предмет: Химия, автор: yarikkoss

найти массу серебра, полученного по реакции масляного альдегида массой 20г с оксидом серебра массой 50г

Ответы

Автор ответа: dmmax

CH3-CH2-CH2-CHO + Ag2O= CH3-CH2-CH2-COOH + 2Ag
n(альдегида) = 20/ 72 = 0,277моль
n(Ag2O)= 50/270 = 0,185моль

M(Ag) = 0.185x2x127= 47г

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1)Reading
John Kennedy
John F. Kennedy was the youngest man who has ever been elected President of the United States. His term ended after two years and ten months when he was shot to death in Dallas, Texas.
Kennedy came from an Irish family that left Ireland during the 1840’s . In America the Kennedys became rich and JFK’s father was a politician and millionaire.
After John had studied politics at Harvard University he joined the US Navy and was commander of a boat during World War II. He became a war hero and was honoured because he rescued the crew of his boat when it was bombed by Japanese airplanes.
In the 1940s Kennedy’s political career began. He became a member of the House of Representatives and later a Senator in his home state of Massachusetts.
In 1960 Kennedy won the race for the White House and became the first Roman Catholic president of the USA. People liked him because he was good-looking and rich. He was a young, dynamic American and he had an attractive wife, Jacqueline.
Kennedy had many things to do during his short presidency. He helped African Americans in their fight for equal rights. He also sent US advisors to Vietnam because the Communists threatened to take control of it. JFK promised to put a man on the moon before the Soviets.
His main problem, however, was Cuba. In 1961 the Soviet Union put missiles, which could attack the US, on the island. When Kennedy threatened to start a war, the Russians removed their missiles.
On November 22, 1963 JFK’s presidency ended when he rode in his open car through the streets of Dallas, Texas. Bullets hit him in the back of the head. He was rushed to hospital but doctors couldn't save his life. Shortly afterwards he died and Vice President Lyndon Johnson became President.
A few hours after the murder Lee Harvey Oswald was arrested, because he was in the building from which the shots came. The police were sure that Oswald was the murderer. A few days later, Oswald himself was killed.
The assassination is still a mystery today. First, it was thought that Oswald acted alone, but today many people think that there were more people involved in Kennedy’s murder.

2) Find the English equivalents for the following
спасти команду, экипаж
равные права
угрожать началом войны
быть застреленным
политическая карьера
привлекательный и богатый
срочно доставить в больницу
быть родом из
быть награжденным, удостаиваться чести
отправить человека на луну

3)Answer the questions
1. How long had Kennedy been the US President?
2. What are the main facts about his Navy experience?
3. When and how did JFK start his political career?
4. Why was Kennedy so popular among American people?
5. What did JFK manage to do for his country?
6. What happened on November 22, 1963?

4)Fill in the correct word or phrase
1.involved 2.remove 3.a boat 4.rescue 5.put a man 6.save 7.a member of 8.problem 9.joined 10.equal rights

1. … the Navy
2. … the missiles
3. Commander of ….
4. … the crew
5. … on the moon
6. … the House of the Representatives
7. main …
8. fight for …
9. … one’s life
10. … in murder

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ДАЮ 50 БАЛЛОВ
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ВСЕЕЕ НОМЕРА
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С 3 НОМЕРА ПО 5
ПРОШУУ
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