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For lactic acid, C3H5O3H, Ka = 1.4 x 10-4.  What [C3H5O3-]/[C3H5O3H] ratio results in a buffer with a pH of 4.00? A. 0.70 B. 1.2 C. 1.4 D. 1.8

A voltaic cell employs the following redox reaction: Sn2+ (aq)  +  Mn (s)  

What are the correct classifications for I, II and III?                   I                             II                           III A.   compound               element                 mixture B.    element                   mixture               compound C.    mixture                   element                compound D. compound                mixture                   element

Consider the following endothermic reaction: 3NO(g)  ⇌  N2O(g)  +  NO2(g) Which process would increase the product concentration for this reaction? A. Decrease the temperature B. Add a catalyst C. Decrease the concentration of NO gas D. Remove NO2 gas

Consider the reaction:   2NO(g)  +  O2(g)  →  2NO2(g)             If the rate of appearance of nitrogen dioxide is 0.040 mol·L–1·s–1, then what is the rate of disappearance of O2? A.   –0.040 mol·L–1·s–1 B.   –0.020 mol·L–1·s–1  C.  –0.010 mol·L–1·s–1  D.  –0.060 mol·L–1·s–1  

What is the net ionic equation for hydrochloric acid and sodium hydroxide?   A. HCl (aq)  +  NaOH (aq)  

The changes in Gibbs free energy,

How many carbon atoms are in 1.0 g of C9H8O4? Molar Mass C9H8O4: 180.16 g/mol   A. 8.30 x 10-26 atoms B. 3.34 x 1021 atoms C. 5.42 x 1024 atoms D. 3.01 x 1022 atoms

If 5.0 mL of acetone (C3H6O) is spilled on a person’s skin, how much heat (in kJ) will be dissipated as it evaporates? Data for C3H6OMolar Mass: 58.08 g/molDensity: 0.791 g/mL

What is the molar concentration of OH- in a solution prepared by mixing 2.5 moles of Mg(OH)2 with sufficient water to make 5.0 L of solution? A. 0.50 M B. 1.0 M C. 1.5 M D. 2.0 M