Above is a potential energy curve of a reaction. It depicts conversion of reactant to product via transition state.
When a catalyst is added to the reaction system, energy barrier of reaction decreases.
It must be noted that energy barrier reaction is defined as energy difference between reactant and transition state.
In present case, energy of reactant is 200 kj, while that of transition state (in absence of catalyst) is 650 kj
Thus, energy barrier of reaction is 650 - 200 = 450 kj
<span>Hence, system must absorb 450 kj of energy for the reaction to start, if no catalyst was used</span>
Helium - 4 isotope has 2 protons and 2 neutrons.
Its atomic number is 2 (the number of protons). Atomic number is the number of protons in the atom of an element and it identifies the element. All the isotopes of an element have the same atomic number (same number of protons). So, all the isotopes of hellium have 2 protons.
The number 4 that identifies the helium - 4 isotope is the mass number, i.e. the number of protons plus the number of neutron. So, helium-4 isotope has 2 protons and 2 neutrons. While, other isotopes of helium have 2 protons but different number of neutrons.
The atomic number enable us to deduce the number of electrons in an atom because the atoms are neutral, which implies that the positive and negative charge are equal. Given that the magnitude of the charge of electons and protons are equal but the sign is opposed (protons are positve and electrons are negative) the number of electrons in the atom equals the number of protonts. That is why the atomic number is also the number of electrons of the atom.
HF and NaF - If the right concentrations of aqueous solutions are present, they can produce a buffer solution.
<h3>What are buffer solutions and how do they differ?</h3>
- The two main categories of buffers are acidic buffer solutions and alkaline buffer solutions.
- Acidic buffers are solutions that contain a weak acid and one of its salts and have a pH below 7.
- For instance, a buffer solution with a pH of roughly 4.75 is made of acetic acid and sodium acetate.
<h3>Describe buffer solution via an example.</h3>
- When a weak acid or a weak base is applied in modest amounts, buffer solutions withstand the pH shift.
- A buffer made of a weak acid and its salt is an example.
- It is a solution of acetic acid and sodium acetate CH3COOH + CH3COONa.
learn more about buffer solutions here
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Answer:
1.64 moles O₂
Explanation:
Part A:
Remember 1 mole of particles = 6.02 x 10²³ particles
So, the question becomes, how many '6.02 x 10²³'s are there in 9.88 x 10²³ molecules of O₂?
This implies a division of given number of particles by 6.02 x 10²³ particles/mole.
∴moles O₂ = 9.88 x 10²³ molecules O₂ / 6.02 x 10²³ molecules O₂ · mole⁻¹ = 1.64 mole O₂
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Part B needs an equation (usually a combustion of a hydrocarbon).
