Explanation:
1. Thermochemical equation is balance stoichiometric chemical equation written with the phases of the reactants and products in the brackets along with the enthalpy change of the reaction.
The given correct thermochemical reactions are:


2. Phase change affect the value of the enthalpy change of the thermochemical equation. This is because change in phase is accompanied by change in energy. For example:


In both reaction phase of water is changing with change in energy of enthalpy of reaction.
Answer:
When the excited electron fall back to the lower energy levels the energy is released in the form of radiations.The characteristics bright colors are due to the these emitted radiations. These emitted radiations can be seen if they are fall in the visible region of spectrum
Explanation:
The electron is jumped into higher level and back into lower level by absorbing and releasing the energy.
The process is called excitation and de-excitation.
Excitation:
When the energy is provided to the atom the electrons by absorbing the energy jump to the higher energy levels. This process is called excitation. The amount of energy absorbed by the electron is exactly equal to the energy difference of orbits. For example if electron jumped from K to L it must absorbed the energy which is equal the energy difference of these two level. The excited electron thus move back to lower energy level which is K by releasing the energy because electron can not stay longer in higher energy level and comes to ground state.
De-excitation:
When the excited electron fall back to the lower energy levels the energy is released in the form of radiations. this energy is exactly equal to the energy difference between the orbits. The characteristics bright colors are due to the these emitted radiations. These emitted radiations can be seen if they are fall in the visible region of spectrum
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After looking at answers I agree with the statement Chemistry is fun.
Answer:
22.8 L
Explanation:
Step 1: Given data
- Moles of the gas (n): 1.35 mol
- Pressure of the gas (P): 1.30 atm
- Ideal gas constant (R): 0.0821 atm.L/mol.K
Step 2: Convert "T" to Kelvin
We will use the following expression.
K = °C + 273.15 = -6 + 273.15 = 267 K
Step 3: Calculate the volume of the gas
We will use the ideal gas equation.
P × V = n × R × T
V = n × R × T / P
V = 1.35 mol × (0.0821 atm.L/mol.K) × 267 K / 1.30 atm
V = 22.8 L
Answer:
The number of atoms contained by one molecule of Iron (II) Sulfate are 6.
Explanation:
Iron (II) Sulfate is mage up of two parts. One is the Positive part which constitutes of Fe⁺² and a negative part which constitutes of a polyatomic anion i.e. SO₄²⁻. As there are four Oxygen and one sulfur atom in sulfate Ion so sulfate ion contains 5 atoms in total. Therefore, five atoms from sulfate iona dn one atom of Iron ion makes a total of 6 atoms in one molecule of Iron (II) Sulfate.