Chem AP Unit 7

A solution is prepared by mixing 1000 mL of 1 M Na₃PO₄ with excess acid. On the basis of the information above, which of the following species is present in the solution at the highest concentration?

• H₃PO₄

• H₂PO₄^-

• HPO₄^2-

• PO₄^3-

Consider the equilibrium above. Which of the following changes will increase the concentration of NH₄⁺

• Adding Nitric Acid, HNO₃

• Removing NH₃

• Adding a catalyst

• Adding Calcium Hydroxide, Ca(OH)₂

Equal numbers of moles of H₂S and CH₄ in a closed system are allowed to reach equilibrium as represented by the equation above. Which of the following species will have the highest concentration when the system reaches equilibrium?

• CH₄

• H₂S

• H₂

• CS₂

• 1x10¹³⁰

• 3x10⁸⁰

• 1x10⁶⁵

• 2x10⁴⁰

• Z<X<Y

• Y<X<Z

• Z<Y<X

• X<Z<Y

• 36

• 16

• 8

• 3

The K_p of the reaction above is 0.064 at 825°C. All of the gases are present in a 1.0 L vessel and in equilibrium. When the volume of the vessel is decreased, what will happen to the pressure

• it will increase

• it will decrease

• it remains the same

• it depends on the temperature

The K_sp of Li₂CO₃ is 1.7x10^-2, what is the molar solubility of Li₂CO_{3 in water}

• $^3\sqrt{\frac{1.7\times10^{-2}}{4}}$

• $\sqrt{\frac{1.7\times10^{-2}}{4}}$

• $^3\sqrt{1.7\times10^{-2}}$
  

• $\sqrt{1.7\times10^{-2}}$

According to the reaction above what will cause the formation of more oxygen gas

• An increase in temperature

• An increase in pressure

• An increase in BaO

• An decrease in BaO₂

• I & II only

• I & III only

• II & III only

• I, II, & III