The number of moles of KF needed to prepare the solution is 3 moles
<h3>What is molarity?</h3>
Molarity is defined as the mole of solute per unit litre of solution. Mathematically, it can be expressed as:
Molarity = mole / Volume
<h3>How to determine the mole of KF </h3>
- Volume = 2500 mL = 2500 / 1000 = 2.5 L
- Molarity = 1.2 M
- Mole of KF =?
Molarity = mole / Volume
1.2 = mole of KF / 2.5
Cross multiply
Mole of KF = 1.2 × 2.5
Mole of KF = 3 moles
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Answer:
Explanation:
Atomic number : It is defined as the number of electrons or number of protons present in a neutral atom.
However, when we talk about the atomic number of the ion, it is not equal to the number of electrons as electron can be gained or loosed.
This is why, more appropriately, the number of the protons which are present in the nucleus of the atom is called the atomic number.
Thus, atomic number of phosphorus = 15
Mass number is the number of the entities present in the nucleus which is the equal to the sum of the number of protons and electrons.
Given, Mass number = 32
Thus, the symbol of the isotope is:-
The heat that creates this temperature change coming from change in the internal energy of the system as per as first law of thermodynamics.
<h3>What is Boyle's law ?</h3>
A law stating that the pressure of a given mass of an ideal gas is inversely proportional to its volume at a constant temperature.
As we know, Boyle's law only works when the gas is kept at a constant temperature
Here,
When volume of gases decreased, it means work done has occurred on the system, so the work done is used for raising internal energy of the gas and the other is released as the thermal energy.
So,
According to 1st law of thermodynamics,
we know Q = ΔU + W i.e, change in internal energy and work done. So this is a reason. Changing temperature occurs.
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There are different formula you need to keep in mind when solving for [OH-]
Given that pH = 6.10
pH + pOH = 14
6.10 + pOH = 14
pOH = 7.9
[OH-] = 10^(-pOH)
[OH-] = 10^(-7.9)
[OH-] = 0.000000013
[OH-] = 1.3 x 10^-8
<h2>
<u>Answer: [OH-] = 1.3 x 10^-8</u></h2>
Given: C3H8(g) + O2(g) ----> CO2 (g) + H2O (g)
Step : Put a 3 in front of CO2 (g) to balance C
=> C3H8(g) + O2(g) ----> 3CO2 + H2O to balance H
Step 2: Put a 4 in front of H2O
=> C3H8 (g) + O2(g) -----> 3CO2 (g) + 4H2O (g)
Step 3: Given that there are 3*2 + 4 = 10 O to the right side, put a 5 in front of O2 to balance O:
=> C3H8(g) + 5O2(g) -----> 3CO2(g) + 4H2O(g)
You can verify that the equation is balanced.
So, the answer is that the coefficient in front of O2 is 5.
