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化学 高校生

なんで初めの時のH+が0になってるんですか?

Cl=35.5 Ag=108 →問題 337 42NO2 。 ただし, 平 Paとする。 発展例題27 緩衝液 問題 343 0.10mol/Lの酢酸水溶液10.0mLに0.10mol/Lの水酸化ナトリウム水溶液 5.0mLを |加えて,緩衝液をつくった。 この溶液のpHを小数第2位まで求めよ。 ただし, 酢酸の | 電離定数をKa=2.7×10 -5 mol/L, log102.7 0.43 とする。 考え方 第Ⅰ章 物質の変化と平衡 解答 ┐(1+α)[mol] OCEE Pa] XP Q2 緩衝液中でも,酢酸の電離平衡 が成り立つ。混合水溶液中の酢 酸分子と酢酸イオンの濃度を求 め、電離平衡の量的関係を調べ ればよい。このとき,酢酸イオ ンのモル濃度は,中和で生じた ものと酢酸の電離で生じたもの との合計になる。これらの濃度 を次式へ代入して水素イオン濃 度を求め, pH を算出する。 0.10x 残った CH3COOH のモル濃度は, 10.0 1000 mol-0.10x 5.0 1000 mol (15.0/1000) L = 0.0333mol/L また,生じた CH3COONa のモル濃度は, 5.0 0.10× mol 1000 (15.0/1000) L 混合溶液中の [H+] を x[mol/L] とすると, =0.0333mol/L CH3COOH 1H+ + CH3COO- はじめ 0.0333 0.0333 [mol/L] = K = [H+][CH.COo-] 平衡時 0.0333-x x 0.0333+x[mol/L] == 0.50 ① ph 問題 342 離し,生じ の電離定数 る。 [CH3COOH] [H+]=[CH3COOH] [CH3COO-] XK② 発展例題28 溶解度積 xの値は小さいので, 0.0333-x=0.0333, 0.0333+x= 0.0333 とみなすと, ②式から [H+]=K』 となるため, pH=-log10[H+]=-log10(2.7×10-5)=4.57 問題 346 347 | 塩化銀AgCIの溶解度積を8.1×10-11 (mol/L)2として,次の各問いに答えよ。 (1) 塩化銀の飽和水溶液1Lには、 何gの塩化銀が溶けているか 化ナトリウム水溶液を

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英語 中学生

英文読解です。左が文章、右が問題です。写真が見にくいかもしれませんが、お願いします。

How Much Is a Tree Worth? It is easy to measure the value of most things that people own. If you want to sell your house or car, for example, an expert will be able to tell you how much money it is worth. However, it's much harder to decide how much things in nature are worth. What is the value, for example, of a tree? One way to measure the value of a tree could simply be in terms of how much money could be made from cutting it down and selling the wood. A tree might be worth more, however, if it isn't cut down. In the case of a fruit tree, for example, we would have to ask how much money could be made by selling the fruit that the tree produces over its lifetime. Furthermore, what about the seeds that tree produces that can grow into new trees that will produce their own fruit? Do these elements add to the value of the original tree? In assessing its value, we might also look beyond the tree itself to the other creatures that live in it. For example, insects, birds, and other animals could not survive without the tree. These creatures use the tree for both food and shelter. Does the fact that the tree supports all these other lives add to the value of the tree itself? Trees also offer non-monetary benefits to people. For example, a tree gives us shelter on a sunny day or provides refuge from heavy rain. How much are these things worth? And what about the beauty of trees that can calm us when we are feeling stressed and that even inspires poetry. How do these kinds of benefits add to the value of the tree? If placing a value on a tree is such a difficult task, placing a value on nature itself is likely impossible. The natural world is an irreplaceable wonder that not only provides humans with many of our basic needs but also inspires us. How do we place value on such a resource? Before You Read Vocabulary CANTON Look at the definitions below. Can you find words that match the definition in the word grid? Some letters have been given to you as clues. Match the words with their definitions below. Definitions worth (n) The importance of an item Reading for Gist Scan the article "How Much Is a Tree Worth?". How many paragraphs are there? Now match each paragraph with the best heading below. There are more headings than you will need. Paragraph 1. Paragraph 2. Paragraph 3. Paragraph 4 produce (v) A person with special skills/knowledge about a subject Paragraph 5. Paragraph 6. value (n) • How much money something should cost creature (n) A small, hard object produced by a plant from which a new plant can grow seed (n) To make or create something Trees add to the beauty of nature. It's impossible to say how much nature itself is worth. How much is a tree worth if we don't cut it down? Different trees offer different kinds of benefits to people. Do the non-monetary benefits that a tree offers add to its value? . Can a tree's value be measured in terms of the wood it provides? Deciding the value of things in nature is a difficult task. Do the creatures that live in a tree add to its value? Reading for Detail Now read the article again in more detail and answer the questions below. According to the article, are the following statements true (T) or false (F)? Underline the part of the text in which you find the answer. monetary (adj) . An animal, especially a nonhuman a. An expert can easily tell you the value of a tree. T/F b. The fruits and seeds that a tree produces might add to its value. T/F c. Many creatures need trees in order to be able to live. T/F d. Trees are only important in terms of the money that they are worth. T/F e. It would be difficult to say how much money nature is worth. T/F expert (n) . Of or relating to money 75 Unit 5: Economics JPREP Empower Vol.76

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