Answer:
hypothesis
Explanation:
that's what they do first
Answer:
A
Explanation:
The solubility of a substance is directly proportional to the temperature. It means that solubility will increase with the increases in temperature. At higher temperature, the kinetic energy increased that allow the solvent molecules to break the solute particles more effectively.
Substance A has a higher solubility because the weight of substance A measured at the end of the experiment is less than the weight of substance B.
Hence, the correct answer is A.
Answer:
1034 yrs
Explanation:
The equation to use in this question is:
t = -2.303/k log (A/A₀) where
A= present number of disintegrations
A₀ = intial number of disintegrations
k = decay constant
The decay constant we will obtain it from the given hal-life:
k: 0.693/t₁/₂, t₁/₂ = half-life ⇒
k: 0.693 / 5730 y = 1.209 x 10⁻⁴ /y⁻¹
t = - 2.303 / 1.209 x 10⁻⁴ /y⁻¹ x log (13.1/15.3) = 1034 yrs
Answer:
A)
Explanation:
Hi,
A) First we need to calculate the heat consumed (because the temperature decreased) by the dissolution process.
All the heat consumed was shown in the change of temperature given that there is no heat loss in the calorimeter.
So:
We know that:
The heat is:
1 mol of the amonium nitrate weighs: 80g/mol:
The heat for 1 mol:
Answer: The true statements are following:
- Energy of the universe is constant; the entropy of the universe increases.
- If a process increases the randomness of the particles of a system, the entropy of the system increases.
- All spontaneous processes release heat.
- Both and must equal zero at equilibrium.
Explanation:
Spontaneous reactions are defined as the reaction which occur on its own and they do not require any external force to start.
- All spontaneous reactions show a positive value for change in entropy. Each spontaneous reaction requires different amount of time.
Hence, the statement all spontaneous reactions occur quickly, is false.
- Entropy of the Universe always increases and energy always changes from one form to another. Hence, the statement energy of the universe is constant; the entropy of the universe increases, is true.
- As entropy is the degree of randomness. So, with increases the randomness of the particles of a system there will also be increase in randomness.
Therefore, the statement if a process increases the randomness of the particles of a system, the entropy of the system increases, is true.
- Some processes are non-spontaneous in nature. Hence, the statement all systems become more disordered spontaneously, is false.
- Since, randomness between the molecules increases so, heat is eventually released in all spontaneous processes. Therefore, the statement all spontaneous processes release heat, is true.
- For a reversible process, entropy change of the Universe is equal to 0. Therefore,
Hence, the statement both and must equal zero at equilibrium, is true.