My friends called me Iron59 because my parents are a chemist and a mathematician. What is my real name?

The following sentence is false. The preceding sentence is true.
Are these two sentences true or false?

I have branches, but no fruit, trunk or leaves. What am I?

What's the only room from which no one can enter or leave

Can you place six X (crosses) in below board without making three in a row in any way ?

A train leaves from point A for point B at 80 mph. After half an hour, another train leaves from point B for point A at 60 mph.

Which of the trains will be farther from point A when they meet ?

Can you count the number of triangles inside a triangle?

How can you spell "White of an egg" in one word?
Hint: I know you can spell coke, poke, and joke.

I am white when I am dirty, and black when I am clean. What am I?

Tarang football website was hacked by one of the players. Jack, the coach of Tarang has pointed out five players as the possible hacker.
Each suspected player made three statements from each suspected player and out of which two are true and one is false.

Joseph
A) I have not hacked the website.
B) I know nothing about hacking.
C) John did it.

Hazard
A) I have not hacked the website.
B) The website was attacked by one of the players.
C) I hate Shelly

Remy
A) I have not hacked the website.
B) I have never seen Oscar in my entire life.
C) I am sure John did it.

John
A) I have not hacked the website.
B) I am sure Oscar did it.
C) Joseph was lying when he said he did it.

Oscar
A) I have not hacked the website.
B) I am sure Hazard did it.
C) I used to be friend with Remy.

So who hacked the website?