Answer:
Molecular compounds are inorganic compounds that take the form of discrete (covalent) molecules. Examples include such familiar substances as water (H2O) and carbon dioxide (CO2).
Answer:
Explanation:
<u>1) Data:</u>
a) m = 18 kg
b) T₁ = 285 K
c) T₂ = 318 K
d) Q = 267.3 kJ
e) S = ?
<u>2) Principles and equations</u>
The specific heat of a substance is the amount of heat energy absorbed to increase the temperature of certain amount (gram, kg, or moles, depending on the definition or units) of the substance in 1 ° C or 1 K.
The mathematical relation between the specific heat and the heat energy absorbed is:
Where,
- Q is the heat absorbed,
- S is the specific heat, and
- ΔT is the temperature increase (T₂ - T₁)
<u>3) Solution:</u>
<u>a) Substitute the data into the equation:</u>
- 267.3 kJ = 18 kg × S × (318 K - 285 K)
<u>b) Solve for S and compute:</u>
- S = 267.3 kJ / (18 kg × 33 K) = 0.45 kJ / (Kg . K)
The options have not units, but I notice that the first answer is 1,000 times the answer I obtained, so I will make a conversion of units.
<u>c) Convert to J /( kg . k):</u>
- 0.45 kJ / (Kg . K) × 1,000 J / kJ = 450 J / (kg . K)
Now we can see that the option A is is the answer, assuming the units.
Answer:
The liquid boils.
Explanation:
Vapor pressure is simply defined as the pressure exerted on a substance (solid/liquid) by the vapor of the substance collected just at the top of the surface of the substance. In concise words, it is the pressure of Vapor that is in contact with its solid or liquid state.
For a liquid, it is the pressure of the Vapor gathering at the top of the surface of the liquid.
When this Vapor pressure matches the external pressure, the temperature stays constant and the molecules of the liquid all through the liquid can gain enough energy, rise to the surface of the liquid and break free in gaseous form; thereby, boiling.
The definition of boiling point basically explains that it is the point at which temperature stays constant, and the vapour pressure of the liquid matches the atmospheric/external pressure around the liquid and its liquid molecules change into vapor.
This is why liquids boil faster at higher altitudes; the atmospheric pressure at higher altitudes is reduced, hence, the temperature at which liquid boils at this high altitude is normally lower than its known boiling point temperature.
It is also why food cooks to a temperature higher than the boiling point of water in a pressure cooker/pot. The added pressure ensures that the cooking water boils at temperatures higher than its boiling point; thereby exposing the cooking ingredients to a higher temperature, leading to faster cooking.
Hence, it is obvious why boiling is the answer to this question.
Answer:
4 moles of Na are needed.
