Physics, 12.12.2020 17:00 ineedtopeebeforethec

0.0884 moles of a diatomic gas are in a piston. When the piston
is compressed, the temperature
drops by 18.8 K, and 83.7 J of
heat flow out. Find W.
(Be careful with + and - signs.
+W = expansion, +Q = added,
+AU = temp goes up)
(Unit = J)

Answers: 2

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Answers

Answer from: stodd9503

W = - 118.24 J (negative sign shows that work is done on piston)

Explanation:

First, we find the change in internal energy of the diatomic gas by using the following formula:

$\Delta\ U = nC_{v}\Delta\ T$

where,

ΔU = Change in internal energy of gas = ?

n = no. of moles of gas = 0.0884 mole

Cv = Molar Specific Heat at constant volume = 5R/2 (for diatomic gases)

Cv = 5(8.314 J/mol.K)/2 = 20.785 J/mol.K

ΔT = Rise in Temperature = 18.8 K

Therefore,

$\Delta\ U = (0.0884\ moles)(20.785\ J/mol.K)(18.8\ K)\\\Delta\ U = 34.54\ J$

Now, we can apply First Law of Thermodynamics as follows:

$\Delta\ Q = \Delta\ U + W$

where,

ΔQ = Heat flow = - 83.7 J (negative sign due to outflow)

W = Work done = ?

Therefore,

$-83.7\ J = 34.54\ J + W\\W = -83.7\ J - 34.54\ J\\$

W = - 118.24 J (negative sign shows that work is done on piston)

Answer from: Quest

Acetic acid /əˈsiːtɪk/, systematically named ethanoic acid /ˌɛθəˈnoʊɪk/, is a colourless liquid organic compound with the chemical formula ch3cooh (also written as ch3co2h or c2h4o2). when undiluted, it is sometimes called glacial acetic acid. vinegar is no less than 4% acetic acid by volume, making acetic acid the main component of vinegar apart from water. acetic acid has a distinctive sour taste and pungent smell. in addition to household vinegar, it is mainly produced as a precursor to polyvinyl acetate and cellulose acetate. it is classified as a weak acid since it only partially dissociates in solution, but concentrated acetic acid is corrosive and can attack the skin.acetic acidnamespreferred iupac nameacetic acidsystematic iupac nameethanoic acidother namesvinegar (when dilute); hydrogen acetate; methanecarboxylic acid[1][2]identifierscas number64-19-7 3d model (jsmol)interactive image3dmetb00009 reference506007chebichebi: 15366 chemblchembl539 chemspider171 drugbankdb03166 echa infocard100.000.528ec number200-580-7e numbere260 (preservatives)gmelin reference1380iuphar/bps1058keggd00010 meshacetic+acidpubchem cid176rtecs numberaf1225000uniiq40q9n063p un number2789inchiinchi=1s/c2h4o2/c1-2(3)4/h1h3,(h,3,4) key: qtbsbxvteameqo-uhfffaoysa-n smilescc(o)=o

Answer from: Quest

we're given that v₀ = 0 and a = 5.4 m/s². therefore, since v = at + v₀ for constant acceleration the equation for velocity is

$v = 5.4 t$