Poll
80%
20%
I think Frieza would kill him. If you use the Gohun later down the road that got much more familiar with his super Saiyan form then I would give it to him (especially looking at the showing against Trunks and a much more powerful Frieza. That fight alone showed signs that Goku was completely holding back against Frieza on planet Namek.)
I agree gohan probably wouldnt be able to maintain the super saiyan transformation, but even if he could he is still around ten years old with not much experience, and at that point in time there is still a significant power gap between gohan and his father. although he may still be stronger than frieza only just. It's only after around a years training that he manages to equal his dad at around the super saiyan 1 forms maximum potential.
Too lazy to find a video of this part, but when SSJ1 Goku was doing the strongest Kahemaheha Wave he could, Frieza (100% final form) eventually broke out of it, got around him, and knocked him deep into a volcano/the planet (and then Gohan temporarily came back to the battlefield to stall for time and yadayada).
Now if Frieza were to do that kind of attack on Gohan when he first reached SSJ1 in the hyperbolic time chamber, I think that would likely put him out of commission, personally, especially with how long it took Goku to recover from that attack.