The difference between とき and じかん
Am i right in thinking that とき is used for specific points/periods in time, for example "the time i went to America",
whereas じかん is used for amounts of time, for example "i studied for 2 hours today"?

Question

The difference between とき and じかん
Am i right in thinking that とき is used for specific points/periods in time, for example "the time i went to America", 
whereas じかん is used for amounts of time, for example "i studied for 2 hours today"?

Answer

You are correct desuyo.　
"the time i went to America"= America ni itta toki(time)
"i studied for 2 hours today" = watashi ha 2jikan(hours) benkyou(study) shimasita.

sometime じかん　show amount of time.