The segment of the periodic table below shows the elements in Groups 1 through 9.What do the elements Mg, Ca, and Sr have in common?  

Which of the following scientists added negatively-charged particles to the model of the atom?  

Use the ΔfG° values in the table above to calculate the ΔrG° (25°C) for the hydrogenation of formic acid shown below. Pay close attention to the phases. HCOOH(ℓ) + H2(g) →CH2O(g) + H2O(g) When giving your answer … Do NOT use scientific notation Use only 3 significant figures in your answer Give your answer in kJ ΔrG°: [deltaG] kJ Is this reaction spontaneous or not spontaneous under standard conditions? If you think it is spontaneous, type “spontaneous” (without the double quotes) in the box. If you think it is not spontaneous, type “not spontaneous” (without the double quotes) in the box. Spontaneous or not spontaneous: [spontaneity]

Thermodynamic tables Substance ΔfG° (kJ mol-1) ΔfH° (kJ mol-1) ΔS° (J mol-1 K-1) CH2O(g) -102.53 -108.57 218.77 HCOOH(ℓ) -361.35 -424.72 128.95 H2(g) 0 0 130.684 H2O(ℓ) -237.129 -285.830 69.91 H2O(g) -228.572 -241.818 188.825 NH3(g) -16.45 -46.11 192.45 NO2(g) 51.31 33.18 240.06 N2O(g) 104.20 82.05 219.85 N2O4(g) 97.89 9.16 77.28  

Gibbs free energy

Below are the Maxwell’s relations (named for James Maxwell),

Based on the fundamental equations, what is

Gibbs free energy

For the reactions below, use the given information to predict which direction the equilibrium will proceed (towards more reactants or towards more products) Reactions Reaction K Current P values Equilibrium reaction will … A. PCl3(g) + Cl2(g) ⇌ PCl5(g) 12.1 PPCl3 = 0.0194 barPCl2 = 0.115 barPPCl5 = 0.515 bar [A] B. N2(g) + 3H2(g) ⇌ 2NH3(g) 0.629 PN2 = 1.00 barPH2 = 0.220 barPNH3 = 0.0151 bar [B]  

a minus lens produces