На грани куба нанесены цифры 1, 2, 3, 4, 5, 6. Три положения этого куба изображены на рисунке 10.39. В каждом случае определите, какая цифра находится на нижней грани
1) Отличить лакмусом кислоту от солей (те нейтральны-фиолетовые, а кислоты даст красную окраску) 2)Влить кислоту в пробирку с одной из солей. В той, что хлорид натрия, выделится хлороводород-газ 2NaCl+H2SO4=Na2SO4+2HCl 3)Методом исключения найти сульфат натрия.
London
Great Britain
1 December
Dear Kate,
Thany you for your letter. It was nice to learn about your school and your classmates. As for my school, it's a big secondary school.
Last year my family moved to London because of my father's job. I wasn't very happy about going to a new school. However, very soon I made new friends and liked the school.
My favourite subjects are Maths, IT and PE. Our school has very good sports facilities: a gym, six tennis courts and a large games field. Phillip, my best friend, often plays football there. But I prefer bascketball or volleyball.
When classes are over, we are bosy too. The teachers encourage the students to take part in various clubs. I have joined the photography and chess clubs recently. Next term, our school theatre group will put on "Tom Sowyer".
We have various school events every month. A week ago we had a Sports Day. Unfortunatelly, Philip and I did not take part in the competitions. We were ill.
What school events do you have? What are your favourite subjects?
Write back soon.
Best wishes,
William.
London
Great Britain
1 December
Dear Kate,
Thany you for your letter. It was nice to learn about your school and your classmates. As for my school, it's a big secondary school.
Last year my family moved to London because of my father's job. I wasn't very happy about going to a new school. However, very soon I made new friends and liked the school.
My favourite subjects are Maths, IT and PE. Our school has very good sports facilities: a gym, six tennis courts and a large games field. Phillip, my best friend, often plays football there. But I prefer bascketball or volleyball.
When classes are over, we are bosy too. The teachers encourage the students to take part in various clubs. I have joined the photography and chess clubs recently. Next term, our school theatre group will put on "Tom Sowyer".
We have various school events every month. A week ago we had a Sports Day. Unfortunatelly, Philip and I did not take part in the competitions. We were ill.
What school events do you have? What are your favourite subjects?
Write back soon.
Best wishes,
William.
2)Влить кислоту в пробирку с одной из солей. В той, что хлорид натрия, выделится хлороводород-газ 2NaCl+H2SO4=Na2SO4+2HCl
3)Методом исключения найти сульфат натрия.