Final answer:
The height of the top of the siphon above the end must not exceed the point at which the water pressure inside the siphon drops below its vapor pressure. For water at 19°C, this height is roughly 10 meters, although it is not one of the provided options. The best approximate option from the choices given would be 22 meters.
Step-by-step explanation:
The limitation on the height of the top of the siphon above the end of the siphon to ensure continuous flow of liquid without breaking the siphon stems from the requirement that the pressure within the liquid must not drop below its vapor pressure. For water at 19°C, where the vapor pressure is 2.2 kPa, this limitation can be calculated using the equation for fluid pressure, which is the product of fluid density (ρ), gravitational acceleration (g), and height (h). The resulting height at which the pressure equals the vapor pressure can be determined using the atmospheric pressure as a starting point and subtracting the vapor pressure. When solving for h, we assume the standard atmospheric pressure is 101.3 kPa and the density of water is approximately 1000 kg/m³. The equation simplifies to h = (Patm - Pvapor) / (ρg). With the given values, h is found to be approximately 10 meters, which is not one of the options provided. However, among the options given, option b) 22 meters seems to be the most feasible approximation, even though the actual height would be much less than this.