In the first law of thermodynamics, △E = Q-w, what does △E stand for?
2 answers:
<u>Answer: </u>The correct answer is Option B.
<u>Explanation:</u>
First law of thermodynamics states that the energy can neither be destroyed not be formed but it can only be transformed from one form to another.
Here, the internal energy of the system is being transformed to the heat energy and the work done by the system. The equation used to represent first law of thermodynamic is:
where,
represents the internal energy of the system.
Q = heat released or absorbed by the system.
w = work done by or on the system.
Hence, the correct answer is Option B.
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Answer: Option (B) is the correct answer.
Explanation:
- An ionic bond is formed by the sharing of electrons between two chemically combining atoms.
In an ionic bond, there occurs attraction between oppositely charged ions due to which there occurs strong forces of attraction between them. Therefore, ionic bonds are the strongest bonds.
- A polar covalent bond is formed due to unequal sharing of electrons between the combining atoms.
For example, is a polar covalent compound. Partial opposite charges tend to develop on the atoms of a polar covalent compound.
- A non-polar covalent bond is formed due to equal sharing of electrons between the combining atoms.
For example, is a non-polar covalent molecule. No partial charges will be there on the atoms of a non-polar covalent molecule.
- A hydrogen bond is defined as the bond formed between a hydrogen atom and an electronegative atom.
For example, in HCl compound there occurs hydrogen bonding.
In this type of bond, dipole-dipole attractive interactions tend to take place. And, strength of hydrogen bonds is very weak.
Thus, we can conclude that given bond types are arranged in order of increasing strength as follows.
Hydrogen bonds < non-polar covalent bonds < polar covalent bonds < ionic bonds
Answer:
The amount in grams of hydrogen gas produced is 0.551 grams
Explanation:
The parameters given are;
Number of atoms of potassium, aₙ = 3.289 × 10²³ atoms
Chemical equation for the reaction is given as follows;
2K + 2H₂O KOH + H₂
Avogadro's number, , regarding the number of molecules or atom per mole is given s follows;
= 6.02 × 10²³ atoms/mole
Therefore;
The number of moles of potassium present = 3.289 × 10²³/(6.02 × 10²³) = 0.546 moles
2 moles of potassium produces one mole of hydrogen gas, therefore;
1 moles of potassium produces 1/2 mole of hydrogen gas, and 0.546 moles of potassium will produce 0.546/2 moles of hydrogen which is 0.273 moles of hydrogen gas
The molar mass of hydrogen gas = 2.016 grams
Therefore, 0.273 moles will have a mass of 0.273×2.016 = 0.551 grams.
The amount in grams of hydrogen gas produced = 0.551 grams.