Breaking a promise made to Allah
Q:
1. If I make a promise and say insha Allah after it, would I have to pay kaffarah if I break that promise? For example, if I say I promise not to eat a chocolate for three days insha Allah and end up eating the chocolate would I have to pay kaffarah for breaking that promise?
2. If I have to pay kaffarah, how much do I have to pay?
3. If I have to pay the kaffarah and I made a few other promises just like that and they're all broken, do I have to pay separately for each, or once for all of them?