CHEM271 Exam 3 Review

True or False? 
 $pH+pOH=pK_w=14.00$  when at 150  $\degree C$  

• True

• False

In acid-base equilibria, the equilibrium will favor the side in which the __________ ("weaker" or "stronger"?) acid or base is present

If HClO₄ is our acid, then what will ClO₄^- strength be?

• strong base

• weak base

• neutral

• weak acid

• strong acid

For $CaCO_3\ \left(s\right)\ \Longleftrightarrow\ CaO\ \left(s\right)\ +\ CO_2\ \left(g\right)$  assume the reaction is at equilibrium. If we take the reaction vessel and place it in the fridge, which of the following will happen (select all)? (assume no phase changes). 

Hint: use the enthalpies of formation to figure out!

•  more precipitation

• greater amount of  $CaCO_3$  formation

• more gaseous formation

• less gaseous formation

• greater amount of  $CaO$  formation

For $CaCO_3\ \left(s\right)\ \Longleftrightarrow\ CaO\ \left(s\right)\ +\ CO_2\ \left(g\right)$ assume the reaction is at equilibrium. What would create more $CO_{2_{ }}$  greenhouse gas emission waste?

• add more  $CaCO_3$  pellets

• have the reaction vessel under vacuum

• add a catalyst to speed up the forwards reaction

• completely remove  $CaO\$  

• expand the reaction volume in a piston

What is the ionization constant, K_a for a weak monoprotic acid if a 0.30 molar solution has a pH of 4.0?

• $3.3\times10^{-8}$

• $4.7\times10^{-2}$

• $1.7\times10^{-6}$

• $3.0\times10^{-4}$

The addition of nitric acid increases the solubility of which of the following compounds?

• KCl (s)

• Pb(CN)₂ (s)

• Cu(NO₃)₂ (s)

• NH₄NO₃ (s)

Is Na₂SO₃ an acidic or basic salt?

• Acidic

• Basic

Phenol, C₆H₅OH, has K_a of 1.0 x 10 ^-10. What is the pH of a 0.010 M solution of phenol? (what is the only reasonable answer?)

• between 3 and 7

• 10

• 2

• between 7 and 10

You are given equimolar solutions of each of the following. Which has the lowest pH?

• NH₃Cl

• NaCl

• K₃PO₄

• Na₂CO₃