At 1489 mm of Hg, water will boil at:

Explanation

At a pressure of 1489 mmHg (millimeters of mercury), water will boil at approximately 120 degrees Celsius (212 degrees Fahrenheit). The boiling point of a substance, such as water, depends on the pressure applied to it. Under normal atmospheric pressure at sea level, which is around 760 mmHg, water boils at 100 degrees Celsius (212 degrees Fahrenheit). However, when the pressure is increased, as in the case of 1489 mmHg, the boiling point of water also increases. At higher pressures, the boiling point of water increases because the additional pressure on the water molecules raises the energy required for them to overcome the intermolecular forces and transition from the liquid phase to the gaseous phase (vaporization). This results in an increase in the boiling point temperature. It's important to note that the boiling point of water can vary with altitude and atmospheric conditions, as the atmospheric pressure changes with elevation. Additionally, impurities and dissolved substances in the water can also affect its boiling point. The value mentioned above (100 degrees Celsius at 1489 mmHg) is an approximate estimation based on the relationship between pressure and boiling point. Although you are not expected to know the calculation of boiling points at various pressures, you must understand that at pressures higher than atmospheric pressure, the boiling point must also be higher than that at atmospheric pressure. This is because the boiling point is defined as the temperature at which the vapor pressure equals the external pressure. So, the higher the pressure, the higher the required temperature to evaporate enough liquid to equal the external pressure. Since 1489 mm of Hg>760 mm of Hg(atmospheric pressure), the boiling point must also be greater than 100. The best option in this case is, therefore, option A. If you have read the book thoroughly, this may just be a factual recall for you: