M=2.65kg=2650g
M=74g/mol
n = m/M = 2650g/74g/mol ≈ 35.81mol
Heat of fusion = 7.27kJ/mol
If 7.27kJ ------------- energy is in --------------- 1mol
than x ------------- energy is in --------------- 35.81mol
x = [35.81mol*7.27kJ]/1mol = <u>260.3387kJ</u>
The last step is to calculate the percent by mass of each element in ammonium nitrate (NH4NO3). The masses of the elements in one mole of the compound are: mass N = 28.0 g mass H = 4.0 g mass O = 48.0 g The molar mass of the compound is 80.0 g/mol. What is the mass of one mole of the compound? 80.0g
3 valence electrons are transferred in the formation of the compound potassium nitride because nitrogen needs 3 valence electron to become stable, or to have the electron configuration of noble Gases.
Generally (but far from universally), the elements within a group have similar characteristics. Antimony, nitrogen, and arsenic are all part of the same group as phosphorous (the pnictogens, or group 5A). Oxygen is not in this group, but rather in an adjacent group (the chalcogens, or group 6A). Thus, the answer here should be oxygen.
That said, there can be very significant differences in characteristics among the elements within a group, and that is certainly the case here. For example, free nitrogen exists predominantly as a molecular gas (N₂) and makes up about 78% of the atmosphere we breathe. Elemental arsenic (As), while in the same group as nitrogen, is naturally found in the solid state and is poisonous to humans (arsenic is sometimes included among the toxic heavy metals, although it’s technically a metalloid).