Answer:
Molecules are made of two or more atoms
Molecules range in size
Molecules are made of atoms of the same element or different elements.
69. The student's skin was obviously warmer than the initial temperature of the bracelet. According to the second law of thermodynamics, heat transfers from a higher temperature to a lower temperature hence heat transfers from the student's skin to the bracelet warming up the bracelet.
70. moles of copper=mass of copper/molar mass of copper
=30.1g/(63.55g/mol)= 0.4736 moles Cu
71. Delta H( heat released) = mCp(deltaT) = 30.1g(0.385 J/gK)(33-19)K = 162.23J
72. Copper is chemically less active than iron.
Below picture contains the given models.
Answer: Option-B is the correct model.
Explanation: Solid is a state of matter in which the particles are closely packed, has definite volume and shape. Like liquids they don't flow, either they occupy the volume of container as that occupied by both gases and liquids. The inter-molecular forces between solid particles are very strong as compared to liquids ans gases. So, the model B has a particles very closely packed to each other.
Answer:
-2024 kJ
Explanation:
The combustion of propane is
C₃H₈(g) + 5O₂(g) → 3CO₂(g) + 4H₂O(g)
And, ΔG° = ΔH° - TΔS°
Where T is the temperature in K.
ΔH° = ∑n*H°f, reactants - ∑n*H°f, products
Where n is the number of moles in the stoichiometry reaction. H°f, O₂(g) = 0 because it's a substance formed by only one element.
ΔH° = [4*(-226) +3*(-398)] - [-100] = -1998 kJ
ΔS° = ∑n*S°, reactants - ∑n*S°, products
ΔS° = [4*(184) + 3*214] - [5*204 + 271] = 87 J/K = 0.087 kJ/K
So
ΔG° = -1998 - 298*0.087
ΔG° = -2024 kJ
Answer:
true
as temperatures rise, the atoms become more active; as per the opposite (meaning as temperatures drop, the atoms start to settle down) liquid is the more medium state (because the temperature rises enough for the solid to become a a liquid but not too much that the liquid evaporates and turns into a gas) have a great day/night