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化学 高校生

読みましたが、全体的に理解出来ません。英語で理解出来なかったので多分、全文和訳しても理解出来ません。 なので、この写真に載っていることを分かりやすく教えていただきたいです🙇🏻‍♀️

Free energy changes determine if a reaction is endothermic or exothermic. Processes in nature are driven in two directions: toward least MAIN IDEA enthalpy and toward greatest entropy. When these two oppose each other, the dominant factor determines th direction of change. As a way to predict which factor will dominate fora given system, a function has been defined to relate the enthalpy and entropy factors at a given temperature tropy and constant pressure. This combined enthalpy-entropy function is callepd t free energy, G, of the system; it is also called Gibbs free energy. This function simultaneously assesses the tendencies for enthalpy and entropy to change. Natural processes proceed in the direction that lowersthefree energy of a system. Only the change in free energy can be measured. It can be defined in terms of changes in enthalpy and entropy. At a constant pressure and temperature, the free-energy change, AG, of a system is defined as the difference between the change in enthalpy, AH, and the product of the Kelvin temperature and the entropy change, which is defined as TAS. Free Energy Change AGO= AH°- TASO Note that this expression is for substances in their standard states. The product TAS and the quantities AG and AHhave the same umor usually kJ. The units of AS for use in this equation are usually N If AG<0, the reaction is spontaneous. AH and AS in the free-energy equation can have positive or negative values. This leads to four possible combinations of terms.

解決済み 回答数: 1
化学 高校生

【英語ですみません】最後の12番は何を書いたら良いのでしょうか…? Video C の実験では、aqueous solution にlead(ii) nitrate, aqueous solution にPottasium iodide を入れていました。 2KI (aq)... 続きを読む

With lead (I) nitrate solution. This precipitation reaction produces a bright yellow solid. (point values in parentheses) Part 1: 1. Copy the unbalanced reaction below into your lab notebook. Balance the reaction by adding coefficients. (1) KI (aq) Pb(NO,), (aq) KNO, (aq) Pbl, (s) 2. a) Which trial are you assigned? b) Copy the data table below into your notebook. Watch video A (make sure it's the correct trial!) and collect your data. You may need to pause or rewatch the video, it goes quickly. (1.5) Mass of Empty Beaker (g) Mass of Beaker+ solid Pb(NO,)。(g) Volume of 1.0 M KI (aq) (mL) For the following calculations, show all your work for full credit. 3. What mass of solid Pb(N0,), was added to the beaker? (1) 4. If the solid Pb(NO,), was dissolved in 45 mL of water, what is the molarity of the Pb(NO,)。 solution? (2.5) 5. Which compound is the limiting reactant? (4) 6. What mass of lead (II) iodide (PbL,) should be produced? (2) Part 2: 7. Watch video B (make sure it's the correct trial!) to see the complete reaction and collection of the product. Copy the data table below and record your data. (1) Mass of filter paper (g) Mass of filter paper + dried precipitate (g) 8. What mass of precipitate was collected? Show your work. (1) Calculate the percent yield for the reaction. Show your work. (2) 10. For your trial, which three ions were present in the filtered solution at the end of the reaction? In other words, which three ions are still dissolved at the end of the reaction? Defend/explain your 9. answer. (3) 11. Watch video C - watch both tests for your trial and record your observations. (1) a) Add lead (II) nitrate - b) Add potassium iodide - 12. These tests were conducted to prove the identity of the limiting reactant. Considering your answers to the previous two questions, describe how these tests support the prediction you made in question 5 about which compound is the limiting reactant. (2)

解決済み 回答数: 1
化学 高校生

問1なのですが解法を見てもさっぱりわかりません。なぜCl-のモル濃度を求めた後に溶解度積をつかうのでしょうか?Ag+は全て反応しきってるという認識で解説を読んでいたのでよくわからなくなりました。誰か解説をお願いいたします。

と。 塩化物イオン CI-やヨウ化物イオンIは水溶液中で銀イオン Ag" や鉛(II)イオンPb?t, 2+ 応して難溶性の塩をつくる。難溶性の塩の飽和水溶液では溶解平衡が成り立っていると考えら る。電離式に化学平衡の法則を適用すると,固体の量は平衡に影響を与えないので, 平衡宗新。 電離式中のイオンのモル濃度のみを用いて表され, その値は温度が変わらなければ常に一定で る。このような定数を溶解度積という。これについて, 下記の各問に答えよ。ただし, logio2s 0.30, log1o 3 = 0.48 とし, 溶解度積は次の値を用いること。 上り 塩化銀 AgCI [Ag*][CI-] =Ksp(AgCI) = 2.0×10-10(mol/L)? ヨウ化銀 AgI [Ag*][I]=Kap (AgI) = 2.0×10-14 (mol/L)? 塩化鉛(II) PbCl2 [Pb?+][CI]? =Ksp(PbCl2) = 1.8×10-5 (mol/L)° 問1 C とIをそれぞれ0.300 mol/L, 0.100 mol/L で含む水溶液 500 mL に, 0.300mol/ の硝酸銀水溶液500 mL をよく撹押しながら加えたところ, 沈殿が生じた。 このとき上澄み に含まれる CI-およびI~のモル濃度はそれぞれ何 mol/L か。 有効数字 2 桁で答えよ。 m目 の 20×10-2 mol/Lの硝酸鉛(IⅡ)水溶液に塩化ナトリウム水溶液を少しずっ加えたときの 24 の の明 は おハ

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