Answer:
ΔH = +26.08 kJ/mol
Explanation:
The change in enthalpy (ΔH) is given in J/mol, and can be calculated for dissolution by the equation:
ΔH = m(water)*Cp*ΔT/n(solute)
The mass of water is the density multiplied by the volume
m = 1g/mL * 25.0mL = 25.0 g
The number of the moles is the mass divided by the molar mass. Knowing the molar masses of the elements:
N = 14 g/mol x 2 = 28
H = 1 g/mol x 4 = 4
O = 16 g/mol x 3 = 48
NH₄NO₃ = 80 g/mol
n = 1.25/80 = 0.015625 mol
So,
ΔH = 25*4.18*(25.8 - 21.9)/0.015625
ΔH = 26,083.2 J/mol
ΔH = +26.08 kJ/mol
Answer: D. Use tools to help improve their senses when they make observations.
Observation is the outcome of a scientific procedure, which is followed to answer the questions related to a scientific inquiry. In order to make observation scientists need to use tools that can help in improving their senses like visual, sensation and hearing aids, so as to make observation accurate, and conclusive in a research.
Decomposition.
Decomposition is the chemical reaction in which a compound breaks down into the two elements or molecules that formed the compound. In this case, Dialuminium Trioxide has broken down into the basic components of Al2 and O2.
Hope this helps!
Answer:
Once I read a NASA post where they were saying that the universe keeps expanding as matter keeps forming and cooling down thus adding to the size of the universe so keeping this in mind, the best answer choice is, <u>option A. The universe is currently expanding and will continue to expand.</u>
B
Solar energy does not give off toxic wastes as nuclear energy does (ex. Chernobyl)
