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Questions in chemistry

[Answered] A certain reaction was performed under a constant pressure of 15.0 atm. During the reaction, the volume contracted from 10.75 L to 3.68 L, and 7.33 kJ of heat was given off. What is $\Delta U$ for this reaction? $(1 L atm =101 J)$

[Answered] Compare the total mass of the reactants to the total mass of the products. What choice demonstrates the Law of Conservation of Mass? [tex]$60 g N _2+130 g O _2 \rightarrow 220 g N _2 O _5$[/tex] [tex]$210 g Ag +80 g Cl _2 \rightarrow 240 g AgCl$[/tex] [tex]$41 gN _2+9 gH _2 \rightarrow 50 gNH _3$[/tex] [tex]$40 g Mn +30 g O _2 \rightarrow 90 g MnO _2$[/tex]

[Answered] What is the name for the $C _2 H _3 O _2^{-}$ ion? A. carboxyhydrate B. acetate C. carbohydroxide

[Answered] Given the following reaction at equilibrium, write the Keq expression. $2 SO_2(g)+O_2(g) \leftrightharpoons 2 SO_3(g)$ A. $Keq =\frac{\left[ SO _2\right]^2\left[ O _2\right]}{\left[ SO _3\right]^2}$ B. $Keq =\frac{\left[ SO _3\right]}{\left[ SO _2\right]\left[ O _2\right]}$ C. $Keq =\frac{\left[ SO _3\right]^2}{\left[ SO _2\right]^2\left[ O _2\right]}$ D. $Keq =\frac{\left[ SO _2\right]\left[ O _2\right]}{\left[ SO _3\right]}$

[Answered] A chemistry student needs 20.0 mL of tetrahydrofuran for an experiment. By consulting the CRC Handbook of Chemistry and Physics, the student discovers that the density of tetrahydrofuran is [tex]$0.889 g^{\cdot} cm ^{-3}$[/tex]. Calculate the mass of tetrahydrofuran the student should weigh out. Round your answer to 3 significant digits.

[Answered] An organic chemist measures the temperature [tex]$T$[/tex] of a solution in a reaction flask. Here is the result: [tex]$T=21.3{ }^{\circ} C$[/tex] Convert [tex]$T$[/tex] to SI units. Round your answer to 4 significant figures.

[Answered] Given the following reaction at equilibrium, write the Keq expression. $2 SO_2(g)+O_2(g) \leftrightharpoons 2 SO_3(g)$ A. $Keq =\frac{\left[ SO _2\right]^2\left[ O _2\right]}{\left[ SO _3\right]^2}$ B. $Keq =\frac{\left[ SO _3\right]}{\left[ SO _2\right]\left[ O _2\right]}$ C. $Keq =\frac{\left[ SO _3\right]^2}{\left[ SO _2\right]^2\left[ O _2\right]}$ D. $Keq =\frac{\left[ SO _2\right]\left[ O _2\right]}{\left[ SO _3\right]}$

[Answered] Complete the table: | | | | :------- | :---------------- | | nitrite | [tex]$NO _2^{-}$[/tex] | | acetate | [tex]$C _2 H _3 O _2^{-}$[/tex] | | permanganate | {[?]} | | {[$\square$]} | [tex]$CrO _4^{-2}$[/tex] | | chlorate | {[$\square$]} | | {[$\square$]} | [tex]$CN^{-}$[/tex] |

[Answered] Calculate the temperature at which technetium becomes superconducting in degrees Celsius. Round your answer to 5 significant figures.

[Answered] A chemistry student needs 30.0 mL of tetrahydrofuran for an experiment. By consulting the CRC Handbook of Chemistry and Physics, the student discovers that the density of tetrahydrofuran is [tex]$0.889 g cm ^{-3}$[/tex]. Calculate the mass of tetrahydrofuran the student should weigh out. Round your answer to 3 significant digits.