It is normal only when it happens occasionally, or after a meal, for someone used to a contented meal every single time. On the other hand, excessive burping(dakaar) or belching can happen due to two reasons.
1.) Excessive air intake:
There are multiple ways that excessive air can reach the food pipe. Sucking on straws, chewing gum constantly and ill-fitting dentures are some common reasons for burping.
2.) Digestive problems: Ulcers in the stomach, prolonged gastric, gallstones and rarely, esophageal or stomach cancers can also cause burping.
However, you could prevent burping by:
*Eat and/or drink slowly: Most of us are pressed for time and eating and/or drinking has now become a task that needs to be finished quickly. Eating fast causes air to be swallowed, and therefore one of the best ways to stop burping is to eat slowly. Sitting in a calm, relaxing environment when eating also allows one to enjoy the food and avoid or stop burping.
*Avoid talking while eating: There is always so much to catch up, whether at home or outside. So, talking while eating is a common practice. This is not just bad manners, but there is also a lot of air that is swallowed, which leads to burping. A solution is to chew the food properly, which not just helps stop burping, but also aids in better food digestion by mixing it adequately with saliva.
*Substitute coke with water: Carbonated drinks are another reason for belching. Replacing them with water, tea, or anything noncarbonated is advisable, not just from burping perspective, but also from the excessive sugar consumption. Carbonated drinks are just sugar solutions, and are absolutely of no nutritive value.
*Avoid straw: When possible, drink from a glass and avoid straws. This reduces the amount of gas taken in and helps stop burping
*Quit smoking: Quitting it has multiple health benefits, and getting rid of smoking is just one of them.
*Dentures: Ill-fitting dentures can be a reason for belching, and so they should be checked and corrected, if required, in a person who has persistent burping.
*Chewing gum: Constantly chewing gum contributes to burping, and so avoiding chewing gum or sucking on hard candy is another way to control burping.
*Avoid certain foods: Foodstuffs like broccoli, cauliflower, lettuce, sprouts, and lentils can produce excessive gas and should be avoided in people who have persistent burping.
In conditions where burping persists even after taking all these precautions and you must consult the doctor!