Answer:
54.075KJ
Explanation:
Since methane is the limiting reactant.
From the reaction equation,
16 g of methane absorbs 206 KJ of energy
4.20 g of methane will absorb 4.20 × 206/16 = 54.075KJ of energy was absorbed.
From the equation, the value of the enthalpy of reaction is positive, this means that energy is absorbed in the reaction of methane and water. Hence the answer.
Answer: Option (A) is the correct answer.
Explanation:
When there occurs no change in the chemical composition of a substance then it is known as physical property.
For example, mass, volume, density are all physical properties.
Since, the mass of an electron is negligible and an electron holds a negative charge.
Therefore, negatively charged particle with very little mass accurately describes the physical properties of electrons in atoms.
Answer:
By the vibration of particles in a medium
Explanation:
For example, the energy in sound waves is transferred by the vibration of the molecules in air.
A is wrong. Electromagnetic radiation transfers energy through vibrating electric and magnetic fields.
B is wrong. Sound waves can transfer energy far from the ocean.
C is wrong. A combination of waves just makes a wave with a different shape.
A thermal insulator because it would keep the heat in
