Can you help to double check my work? Thanks. Contd Gas Relationships-calculatio

Question

Can you help to double check my work? Thanks.

Contd Gas Relationships-calculations R-0 Latm 0,08206 Given: 4 KO2(s) 2 co2lg) 2 K2co3(s) 3 02(gl and vapor pressure of water is 18.7 Torr, MM 1382 at 21 MM-71.1 a student colected 483 mL of o2 over water at 21 ooc and a total pressure of 758.4 torr from the reacton of impure Ko2 with carbon dioxide, co2 a. What is the partial pressure of 02 and how many moles of o2 were collected 8 pt PT P02 PH20 b. How many liters of Co2 at STP would have been needed to produce the amount B pt of O2 above 04 a L lf the impure Ko2 weighed 0.3750 g, what is the by mass of Ko2 in the sample 10 pt.

Explanation / Answer

a)The first one is correct.

b) From the equation 2 moles of CO2 on reaction with KO2 produces 3 moles ofO2

Thus to give 0.00194 moles of O2 we need =0.0019x2 /3 = 0.001267 moles of CO2

c) theoretically 4 moles of KO2 react with CO2 to give 3 moles of O2

Thus 4 x 71.1 g of KO2 should have given 3 moles of O2

so 0.00194 moles of O2 is given by = 0.00194x 4 x71.1 /3=0.1839g

But the impure sample has 0.3750 g

Thus purity of sample = 0.1839x100/ 0.3750 = 49.04 %

Related Questions

Navigate

• Browse (All)
• Browse C
• Subjects

---