Short answer is No,
Sit Ups are great for tightening your abdominal muscles, they will strengthen and tone your rectus abdominus, transverse abdominus and oblique abdominal muscles, all these muscles are great at core strength.
For you to get the full benefits of sit-ups, you should do 3 sets of 8-12 repetitions, 3 times a week
But does that burn belly fat? NO
To burn belly fat, you would need about 45 minutes to an hour of high intensity exercises, like running, playing soccer or basketball, jumping, skipping rope etc.
You would also need to reduce your intake of alcohol and fast foods and processed foods. Those are belly foods
People think that building a muscle automatically reduces the fat around that muscle, a phenomenon known as spot reduction, this is not true and is only a myth
You cannot target one area of fat to work on and lose, you must lose all fat
Build your abs alright, but they won’t make your belly fat, you would lose belly fat from diet and exercises alone
Take my word for it