Oxygen can be produced in the laboratory by the reaction:
2KClO 3 (s)$\rightarrow$ 2KCl(s)+ 3O 2 (g)
How many moles of potassium chlorate are needed to produce 257 mL of oxygen, Collected over water at 14 $\omicron $ C and 97.6 kPa? The vapor pressure of water at 14 $\omicron $ C is
1.60 kPa.
A) 6.89 *10 - 3
B) 7.00 *10 - 3
C) 7.12 * 10 - 3
D) 2.06 * 10 - 3
E) 1.55 * 10 - 3

Question

Oxygen can be produced in the laboratory by the reaction:
2KClO 3 (s)$\rightarrow$ 2KCl(s)+ 3O 2 (g)
How many moles of potassium chlorate are needed to produce 257 mL of oxygen, Collected over water at 14 $\omicron $ C and 97.6 kPa? The vapor pressure of water at 14 $\omicron $ C is
1.60 kPa.
A) 6.89 *10 - 3 
B) 7.00 *10 - 3 
C) 7.12 * 10 - 3 
D) 2.06 * 10 - 3 
E) 1.55 * 10 - 3

Quizplus · Accepted Answer

First, calculate the pressure of oxygen by subtracting the vapor pressure of water from the total pressure: 97.6 kPa - 1.60 kPa = 96.0 kPa. Convert the volume of oxygen to liters: 257 mL = 0.257 L. Use the ideal gas law, PV = nRT, to find moles of O2, where R = 8.314 J/(mol·K) and T = 287 K (14°C + 273). Solve for n (moles of O2), then use the stoichiometry of the reaction to find moles of KClO3.

Oxygen Can Be Produced in the Laboratory by the Reaction →\rightarrow→

Oxygen Can Be Produced in the Laboratory by the Reaction $\rightarrow$