1 / 2

Calculate the Δ H ° rxn for the following reaction.

Calculate the Δ H ° rxn for the following reaction. Δ H ° f [AsH 3 ( g )] = 66.4 kJ/mol; Δ H ° f [H 3 AsO 4 ( aq )] = -904.6 kJ/mol; Δ H ° f [H 2 O( l )] = -285.8 kJ/mol H 3 AsO 4 ( aq ) + 4H 2 ( g ) → AsH 3 ( g ) + 4H 2 O( l ) . -1981.4 kJ -685.2 kJ -172.2 kJ 172.2 kJ 685.2 kJ.

janna
Download Presentation

Calculate the Δ H ° rxn for the following reaction.

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Calculate the ΔH°rxn for the following reaction. ΔH°f [AsH3(g)] = 66.4 kJ/mol; ΔH°f [H3AsO4(aq)] = -904.6 kJ/mol; ΔH°f [H2O(l)] = -285.8 kJ/molH3AsO4(aq) + 4H2(g) → AsH3(g) + 4H2O(l)  • -1981.4 kJ • -685.2 kJ • -172.2 kJ • 172.2 kJ • 685.2 kJ Calculate the ΔH°rxn for the following reaction. ΔH°f [AsH3(g)] = 66.4 kJ/mol; ΔH°f [H3AsO4(aq)] = -904.6 kJ/mol; ΔH°f [H2O(l)] = -285.8 kJ/molH3AsO4(aq) + 4H2(g) → AsH3(g) + 4H2O(l)  ANSWER: -172.2 kJ

  2. The highly exothermic thermite reaction, in which aluminum reduces iron(III) oxide to elemental iron, has been used by railroad repair crews to weld rails together. 2Al(s) + Fe2O3(s) → 2Fe(s) + Al2O3(s) ΔH = -850 kJ What mass of iron is formed when 725 kJ of heat are released? (Molar Masses: Fe: 55.85 g/mol, Al: 26.98 g/mol, Fe2O3: 159.7 g/mol, Al2O3: 102 g/mol) 2Al(s) + Fe2O3(s) → 2Fe(s) + Al2O3(s) ΔH = -850 kJ What mass of iron is formed when 725 kJ of heat are released? ANSWER: 95 g (A)  47 g (B)  130 g (C)  112 g (D)  95 g (E)  65 g

More Related