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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)

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化学 高校生

教えてください。 e -(電子)を揃えるところまではできるのですが、 そこから両辺にK +(カリウム?)とSO42-(硫酸?)を加えるところがわかりません。 理解力が少ないので説明お願いいたします。

酸化還元反応式の作り方 (例1)硫酸酸性の過酸化水素H202とヨウ化カリウムKIの反応 酸化剤 H202+ 2H++ 2e-→ 2H20 還元剤 21- → 12+ 2e *2 の+のより H2O2+ 2 1+2H+ →12+2H20 両辺に2K*とSO。2-を加える。 H2O2+ 2KI+ H2SO4→12 + 2H20 + K2S0。 化学反応式 *……イオン反応式 (例2)硫酸酸性の過マンガン酸カリウムKMnO』と過酸化水素H202の反応 酸化剤 MnO。-+ 8H++ 5e → Mn?+ + 4H20 還元剤 H2O2 → 02+ 2H++ 2e- O×2+2×5より 2MnO4-+ 5H202+6H+ → 502+ 2Mn?+ + 8H20 両辺に2K*と3SO42+を加える。 2KMnO』+ 5H202+ 3H2SO4 → 502+ 2M SO4+ 8H20 + K2SO4 (例3)硫酸鉄(11) FeSO4と硫酸酸性の過酸化水素H202の反応 酸化剤 H202+ 2H++ 2e-→ 2H20 還元剤 Fe2+ → Fe3++e の+2×2より 2Fe2+ + H202+ 2H+ → 2F|3+ + 2H20 両辺に3SO42-を加える。 2FeSO4+ H202+ H2SO4→ Fe2(SO4)3+2H20 (例4)硫化水素H2Sと二酸化硫黄SO2の反応 酸化剤 SO2 + 4H++ 4e-→→S + 2H20 還元剤 H2S → S + 2H++ 2e O+2×2より SO2+2H2S → 3S + 2H20 (例5)二酸化硫黄SO2と硫酸酸性のニクロム酸カリウムK2Cr2O,の反応 Cr2O,?- + 14H*+ 6e-→ 2Cr 3+ + 7H20 酸化剤 502+ 2H2O → SO42- + 4H++ 2e O+2×3より Cr2O,?- + 2H*+ 3S02 → 2Cr3+ 3SO42-+ H20 両辺に2K*とS0。2-を加える。 K2Cr207+ H2SO4+ 3S02→ Cra(S04)3+ K2SO4+ H20

解決済み 回答数: 1