Answer:
ΔH = -20kJ
Explanation:
The enthalpy of formation of a compound is defined as the change of enthalpy during the formation of 1 mole of the substance from its constituent elements. For H₂S(g) the reaction that describes this process is:
H₂(g) + S(g) → H₂S(g)
Using Hess's law, it is possible to sum the enthalpies of several reactions to obtain the change in enthalpy of a particular reaction thus:
<em>(1) </em>H₂S(g) + ³/₂O₂(g) → SO₂(g) + H₂O(g) ΔH = -519 kJ
<em>(2) </em>H₂(g) + ¹/₂O₂(g) → H₂O(g) ΔH = -242 kJ
<em>(3) </em>S(g) + O₂(g) → SO₂(g) ΔH = -297 kJ
The sum of -(1) + (2) + (3) gives:
<em>-(1) </em>SO₂(g) + H₂O(g) → H₂S(g) + ³/₂O₂(g) ΔH = +519 kJ
<em>(2) </em>H₂(g) + ¹/₂O₂(g) → H₂O(g) ΔH = -242 kJ
<em>(3) </em>S(g) + O₂(g) → SO₂(g) ΔH = -297 kJ
<em>-(1) + (2) + (3): </em><em>H₂(g) + S(g) → H₂S(g) </em>
<em>ΔH =</em> +519kJ - 242kJ - 297kJ = <em>-20 kJ</em>
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I hope it helps!
First, calculate the amount fo Na2O that should be produced with the given amount of sodium using proper dimensional analysis and the balanced chemical reaction,
theoretical amount of Na2O = (54.1 g of Na)(1 mol Na/23 g Na)(2 mos Na2O/4 mols Na)(62 g Na2O/ 1mol Na2O)
theoretical amount of Na2O = 72.9 g of Na2O
Calculation of percent yield,
% yield = (61.8 g Na2O) / (72.9 g of Na2O) x 100%
% yield = 84.75%
Answer: 84.75%
Explanation:
Normally, fusion involves two heavy hydrogen nuclides but since we have 4 light hydrogen nuclides, two of which underwent positron emission, thus changing two protons into neutrons plus 2 positrons and 2 neutrinos. The resulting nucleus from this fusion reaction is an He-4 nucleus.
Answer:
A, B, and C are the correct answers.
Explanation:
The reason why solid, liquid, and gas are the most common of the elements because usually in school they teach you more about those 3 elements more than plasma ( from where I am ). Also, all of these states behave differently. Liquid is a substance that flows freely but is of constant volume, having a consistency like that of water or oil. Solid is firm and stable in shape. And gas is an air like substance. I'm not sure how to explain this more, it sounded better in my head. Hope this helped though!
Answer:
Moreover, increasing use of fossil fuels also causes serious environmental problems. Hence, there is a pressing need to use renewable energy sources like solar energy, wind, tide, biomass and energy from waste material. (i) it reduces the dependence on fossil fuels for energy. (ii) they donot produces pollution.
