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化学 高校生

なぜ中和滴定の実験でフェノールフタレインを使うのですか? フェノールフタレインの変色域は8~10で中和のpH7では変化しないと思うのですが。 それとも中和は7と決まっているものではないのですか?? 中和滴定の教科書のページをみると組み合わせの水溶液で中和点のpHが異なって... 続きを読む

一っ >中和滴定 酸と塩基の水溶液とも らか一方の濃度がわかっていれば、 B-中和滴定 すきまを空け ながら水溶液 を注ぐ 液面の底を 目盛にあわ 液面の底の数値 を、最小目区の 1/10まで読む (目盛は上から ふってある) てきてい せる >p.151 neutralization titration 安全ピペッター ビュレット 濃度がわかっている 水酸化ナトリウム水溶液 -ホール ピペット 濃度未知の 酢酸水溶液 標線 ーフェノール ービュレットの先端 まで液を満たす フタレイン 液面の底を (指示薬) コニカル ピーカー 標線にあわ 指示薬が変 滴下をやと せる ビュレットに濃度のわかって いる水酸化ナトリウム水溶液 を入れる。 水酸化ナトリウム 水溶液を滴下する。 iPP 濃度未知の酢酸水 溶液の一部をピー カーにとる。 酢酸水溶液を安全ピベッター を使用しホールピペットで 吸い上げる。 吸い上げた酢酸水 溶液をコニカルヒピ ーカーに流し出す。 コニカルピーカー に指示薬を加える。 濃度が正確にわかっている水溶液 参考 中和滴定は,濃農度が正確にわかっている酸または塩基の水溶液 ↑図16 中和滴定による酢酸水溶液の濃度決定 iの濃度を決め

解決済み 回答数: 2
英語 高校生

(24)がなぜ3になるのか わかる方いらっしゃったら解説お願いしますm(_ _)m

Cows Need Friends Milk production is big business. In North America, for example, one person consumes on average over 150 kilograms of milk every year. To supply the huge amount needed, big farms use machines that automatically feed cows and take their milk. Because ( 24 ), the cost of producing milk is lower. On such farms, though, it is easy for diseases to spread from one animal to another. This can lead to many cows dying on one farm. As a result, cows are often kept separately from a young age. Scientists in Canada researched the effects of keeping young cows in this way. They compared such cows with ones that had been kept with another cow. The researchers showed a red plastic container, which the cows had never seen before, several times to each cow. The cows that had been kept in pairs were interested in the container_at first but soon ignored it. ( 25 )。 the cows that had been kept alone continued to react as if it was the first time they had seen the Container. The researchers concluded that cows kept alone are more sensitive to new things. This is important news for farmers. If cows cannot get used to the feeding and milking machines, milk production slows down. The researchers believe farmers would have fewer problems with feeding and milking if cows were kept in very small groups, rather than separately. The researchers also say that diseases are not sucha big problem for small groups. There should be little risk of ( 26 ) if only two or three of them are kept together. (24) 1 each cow is much larger 2 the milk can be kept longer 4 cheaper food is being used proie 3 fewer people are needed (25) 1 Later on 2 At last 3 In other words 4 On the other hand (26) 1 feeding cows too much 3 wild animals attacking 2 losing many animals 4 young cowS staying healthy

解決済み 回答数: 1
英語 高校生

英検の過去問の長文です 26の問題の答えがなぜ1なのか分かりません わかる方いらっしゃったら解説お願いしますm(_ _)m

Grade 2 2 の に知 もの 12 さい。 B A Good Way to Save Space In recent years, famers in many countries have been finding it more and more difficult to produce enough food to feed everyone. One reason for this is changes in weather patterns caused by global warming. As global temperatures increase, many places have become too hot and dry to be used for agriculture. 24 ), there is increasing pressure to produce renewable energy, such as Solar power. The problem with solar power, though, is that solar panels take up a lot of space, To solve both these problems at once, researchers have recently come up with a way to combine solar power and crop production. 25 One common challenge in farming is that a lot of direct sunlight ( Not only can it cause the leaves to turn brown and dry, but the heat from the sunlight also quickly dries up the water in the ground. This means that the plants do not get enough water to survive. The researchers decided to set up solar panels at about 2.5 meters above the ground. These created a space with shade for plants and also reduced the amount of water that dried up, which helped to increase crop production. The solar panels were also able to benefit from the crops. Solar panels do not ). However, crops like lettuce and kale create a cooling perform well ( 26 effect, which stops the solar panels from overheating and allows them to work more efficiently. The results of this research show that it is possible to produce more food, save space, and enjoy the benefits of solar power. 2(24) 2 At the same time 1 Without this 3 After a while 4 Indeed |(25) 2 is difficult to find 1 damages crops 3 attracts more insects 4 makes vegetables taste bad (26) at high temperatures 1 2 near cool water 3 under large trees 4 on cloudy days dial 20年度第3回検定一次試験(2級) copyright2021 公益財団法人日本英語検定協会 無断転載·複製を禁じます

解決済み 回答数: 1