The boiling temperature of nitrogen is â195.8 Â°C (â320.4 Â°F), about 13 Â°C (â23 Â°F) below that of oxygen, which is therefore left behind. Nitrogen can also be produced on a large scale by burning carbon or hydrocarbons in air and separating the resulting carbon dioxide and water from the residual nitrogen.
Acidic foods like citrus fruits can stimulate acid production and increase heartburn. Avoid oranges, grapefruit, lemons and their juice. Like citrus fruits, tomatoes and products made from tomatoes (tomato sauce and paste, tomato juice) can stimulate the stomach to produce more acid.
1 Check with your health care team before increasing the amount of lemon in your diet and attempting to use it to improve health. Ask for advice on how to incorporate it and how much. You do not need to drink high amounts of lemon juice to gain benefits.  Lemon can cause heartburn.