Перейти к выбору ответа 04.05.2022Сколько килограммов воды нужно добавить к 2 кг 20%-ного раствора, чтобы получить 10%-ный раствор? Выбрать другой вопрос Смотреть ответ Перейти к выбору ответа Химия Ответ учителя по предмету Химия 20% : 20×2÷100=0.4 кг 0.4 кг — это 10 процентов в 4кг. 4кг-2кг=2кг
Похожие вопросы от пользователей
Пожалуйста, срочно! Даю 50 баллов!
1. …. (ever, to meet) Mr Smith? — Yes, we (to meet) in Moscow some years ago.
а. Have you ever met, met
б. Did you ever meet, have met
в. Did you ever meet, met
г. Have you ever met, have met
2. Miss Pavlova (not, to arrive, yet). But she (to phone) an hour ago.
а. did not arrive yet, phoned
б. has not arrived yet, has phoned
в. has not arrived yet, phoned
г. did not arrive yet, has phoned
3. When (you, to visit) your English business partners last? ….(ever, to be) to London?
а. have you visited, Were you ever
б. did you visit, Have you ever been
в. did you visit, Were you ever
г. have you visited, Have you ever been
4. We (not, to discuss) the terms of the contract yet, we (to be) very busy yesterday.
а. did not discuss, have been
б. did not discuss, were
в. have not discussed, were
г. have not discussed, have been
5. How many offers (Mr Petrov, to receive) this month? ….(ever, to do) business with James&Co?
а. did Mr Petrov receive; did he ever do
б. did Mr Petrov receive; Has he ever done
в. has Mr Petrov received; Has he ever done
г. has Mr Petrov received; did he ever do
6. We (already, to inspect) the equipment. We (to make) it yesterday.
а. already inspected, made
б. have already inspected, have made
в. already inspected, have made
г. have already inspected, made
7. Last year I (to publish) only one article. This year I (to publish) three articles.
а. have published, published
б .published, have published
в. have published, have published
г. published, published
8. We (to test) the new model, (to improve) it and then (to show) it at the exhibition.
а. tested, improved, have shown
б. have tested, have improved, showed
в. have tested, improved, showed
г. tested, improved, showed
д. have tested, have improved, have shown
9. … (to signed) the contract yet? When (you, to sign) it?
а. Did you sign, did you sign
б. Have you signed, did you sign
в. Did you sign, have you signed
г. Have you signed, have you signed
10. Yesterday we (to sign) the contract and (to invite) our business partners to a restaurant.
а. have signed, have invited
б. signed, have invited
в. have signed, invited
г. signed, invited
509² — 491²