If you eat egg with salmonela and then 2g of ascorbic acid - is that enough to kill the bacteria in you gut and avoid infection?

No: If certain of exposure to salmonella should report to your doctor for your own good and for purposes of public safety. The infection is usually self-limited and manifests with fever, abdominal cramps, and diarrhea, lasting no longer than a week in most cases. Some experience severe diarrhea which requires aggressive fluid treatment and antibiotics.