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

On 26-01-2022, Juli was murdered at her house in a city in India in the afternoon. There were three suspects in the murder and the following are the statements that were given by them:

John: I visited my village that day.
Jacob: I was out to deposit my house tax in the municipality office at that time.
Jonny: I was at a friend's place having lunch at that time.

Can you find out who is the murderer?

I have one of the three numbers: 1, 2, or 3 in my mind. I speak only truth. You can ask me just one question for which I will only reply in yes or no or don't know. What question will you ask from me so that you are able to know the number?

Count the number of lines in the image below ?

What can you hold in your right hand, but never in your left hand?

Three fair coins are tossed in the air and they land with heads up. Can you calculate the chances that when they are tossed again, two coins will again land with heads up?

There was an aeroplane crash, every single person died, but two people survived. How is this possible?

Can you count the number of lines in the below picture?

The dirtier I get, the whiter I look. Who am I?

With the help clues provided in the image, can you find the 5 digit key?