Q = mCΔT
Q is heat in joules, m is mass, C is specific heat, and delta T is change in temp
2099 J = (40.27g)(C)(148.5 - 24.8) = .421 J / gram K
Let's identify first the phases of matter inside each of those beakers. The first beaker on the left has a compact shape and has its own volume. So, that must be solid. The middle beaker has a compact shape but it takes the shape of its container. So, that must be liquid. The third beaker on the right is gas because the molecules are far away from each other.
After identifying each states, let's investigate the energy for phase change. Let's start with the arrows pointing to the right. The first arrow to the right is a phase change from solid to liquid. The intermolecular forces in a solid is the strongest among the three phases of matter. So, you would need an input of energy to break them apart into liquid. The same is true for the phase change from liquid to gas. Therefore, all the arrows pointing to the right require an input of energy.
The reverse arrows pointing to the left needs to release energy. The molecules in the gas state are free such that they can travel from one point to another easily. They have the highest amount of energy. So, if you want the molecules to come closer together, you need to remove the energy to keep them in place. Therefore, the arrows pointing to the right require removal of energy.
Answer: The excess amount changes from a gas into a liquid or solid (ice). The process of water changing from a gas to a liquid is called "condensation," and when gas changes directly into a solid, it is called "deposition." These two processes are how clouds form.
Answer:
Ethanol
Explanation:
2 C atoms and a single OH group.
Formula: C2H5OH
Answer:
3 × 10⁴ kJ
Explanation:
Step 1: Write the balanced thermochemical equation
C₃H₈(g) + 5 O₂(g) ⟶ 3 CO₂(g) + 4 H₂O(g) ΔH = -2220 kJ
Step 2: Calculate the moles corresponding to 865.9 g of H₂O
The molar mass of H₂O is 18.02 g/mol.
865.9 g × 1 mol/18.02 g = 48.05 mol
Step 3: Calculate the heat produced when 48.05 moles of H₂O are produced
According to the thermochemical equation, 2220 kJ of heat are evolved when 4 moles of H₂O are produced.
48.05 mol × 2220 kJ/4 mol = 2.667 × 10⁴ kJ ≈ 3 × 10⁴ kJ
