Chemistry Test Science Olympiad

Identify all of the following actions that would increase the pH of a saturated Ca(OH)2 solution, given the dissolution process is exothermic:

• Adding hydrochloric acid

• Adding sodium hydroxide

• Doubling the volume by adding water

• Increasing the temperature

Gaseous PCl3 and Cl2 are allowed to react reversibly and exothermically to produce gaseous PCl5 in a container with a movable piston until equilibrium is reached, with an external pressure of 1 atm. Which of the following will increase the equilibrium pressure of PCl5?

• Removing some gas from the system

• Heating the system

• Pressing down on the piston

• Adding neon gas

• Adding a catalyst

The ionization of ammonium ion is endothermic: NH4+ (aq) + H2O(l) ⇌ NH3 (aq) + H3O+ (aq). Which changes will result in the increase in pH of a 0.100 M solution of NH4Cl?

• Diluting the solution from 0.100 M to 0.0500 M

• Bubbling ammonia

• Raising the temperature

• Adding HCl

• Adding NaCl

Tags

NGSS.HS-PS1-6

NGSS.HS-PS1-5

Which of the following will increase [Cl−] in a saturated solution of AgCl in contact with excess solid AgCl?

• Adding silver nitrate

• Adding ammonia

• Doubling the volume by adding water

• Adding Silver chloride

Tags

NGSS.HS-PS1-5

A mixture of gaseous N2O4 and NO2 is at equilibrium in a constant pressure container. Which of the following changes will decrease the number of moles of N2O4 present at equilibrium, given the decomposition of N2O4 is an endothermic process?

• Heating the container

• Adding Neon gas

Tags

NGSS.HS-PS1-5

Which of the following has the smallest molar solubility in 1.0 M HCl(aq)? (Select only one)

• ZnC2O4 (Ksp = 2.7×10^−8)

• BaCrO4 (Ksp = 2.3×10^−10)

• CaF2 (Ksp = 3.9×10^−11)

• AgBr(Ksp=5.0x10^-13)

Tags

NGSS.HS-PS1-6

Tags

NGSS.HS-PS1-6

Tags

NGSS.HS-PS1-7