Video: Qhov delta H ntawm MgO yog dab tsi?
2024 Tus sau: Miles Stephen | [email protected]. Kawg hloov kho: 2023-12-15 23:36
1 Teb. Tus qauv enthalpy hloov kev tsim, lossis Δ H ∘f, ib magnesium oxide -601.6 kJ/mol.
Ua li no, tus qauv enthalpy ntawm kev tsim MgO yog dab tsi?
-601.7 kJ/mol
Ib yam li ntawd, kuv yuav suav delta H li cas? Siv cov qauv ∆ H = m x s x ∆T to solve. Thaum koj muaj m, qhov loj ntawm koj cov reactants, s, qhov tshwj xeeb kub ntawm koj cov khoom, thiab ∆T, qhov kub thiab txias hloov ntawm koj cov tshuaj tiv thaiv, koj tau npaj los nrhiav cov enthalpy ntawm cov tshuaj tiv thaiv. Tsuas ntsaws koj qhov tseem ceeb rau hauv qauv ∆ H = m x s x ∆T thiab multiply los daws.
Dhau li ntawm qhov no, puas yog MgO thiab HCl exothermic?
Kanika Gupta: koj puas xav tau ntau tus thwjtim? Magnesium oxide ( MgO ) yog tsim thaum magnesium (Mg) hlawv ntawm qhov kub thiab txias, ua kom lub teeb ci, kub kub. Thaum cov khoom Mg reacts nrog HCl ( hydrochloric acid magnesium chloride (MgCl2), hydrogen gas, thiab cua sov yog tsim. Thaum tshav kub kub yog tsim vim cov tshuaj tiv thaiv exothermic.
Yuav ua li cas muaj pes tsawg grams ntawm magnesium oxide yog hais tias lub tshav kub hloov los ntawm combustion ntawm magnesium yog kJ?
18 mol mg. 18 molMg x 24.3 g /molMg = 4.37gMg x -108kJ 7.25 g ntawm MgO yuav raug tsim yog tias lub tshav kub hloov zuj zus los ntawm combustion ntawm Mg yog -108kj. Qhov no tau suav los ntawm kev tsim qhov piv ntawm cov moles siv thiab cov kub hloov zuj zus , thiab tom qab ntawd muab qhov tshwm sim los ntawm molar pawg ntawm MgO.
Pom zoo:
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