A mixture of oxygen,hydrogen, and nitrogen gases exerts a total pressure of 282 kPa. If the partial......?

There are 2 total pressures, 282 kPa and 378 kPa, appear in the question.

If total pressure = 282 kPa
P(O₂) + P(H₂) + P(N₂) = P(Total)
(112 kPa) + (101 kPa) + P(N₂) = 282 kPa
Partial pressure of N₂, P(N₂) = (282 - 112 - 101) kPa = 69 kPa
(Your answer is incorrect.)

If total pressure = 378 kPa
P(O₂) + P(H₂) + P(N₂) = P(Total)
(112 kPa) + (101 kPa) + P(N₂) = 378 kPa
Partial pressure of N₂, P(N₂) = (378 - 112 - 101) kPa = 165 kPa
(Your answer is correct.)

65

Looks like you've read your question wrong bud. The question you posted says total pressure is 282 kPa and in the description you have 378 kPa. If the corect total pressure is 378 kPa then you are right, if not then the answer is 69 kPa.

I reckon it might be time to take a little break from the study hahaha

Is the total pressure 282kPa or 378kPa -
If 378kPa , then partial pressure N2 = 378 - ( 112+101) =165kPa
If 282kPa , then partial pressure N2 = 282 - (112+101) = 69kPa.