Ammonia Hitting 20C-50C

The 10 litres will expand to about 10.84 liters. The pressure developed is limited by whatever part of the containment leaks or breaks or deforms first. This is known as hydrostatic expansion.

Liquids have coefficients of volumetric expansion, which vary only slightly over small ranges of temperature, but would graph as a curve over a large temperature range. In the case of liquid ammonia in your range, the CE_v is ~0.0028/°C. For the 30° of warming, 0.0028 x 30 = 0.084, or an 8.4% increase in volume.