Answer:
The heat of reaction when hydrogen and oxygen combine to form water is :
<u>C. 571.6 kJ</u>
Explanation:
Enthalpy Change = The enthalpy change for the formation of 1 mole of the substance from their standard state is called the enthalpy of formation.
This is intensive quantity as it is fixed for 1 mole .
Intensive properties = Those properties which are independent on the amount of the substance are intensive properties.
The value of these quantities does not get halve if you divide the substance into two equal parts. example , density, refractive index.
However , the enthalpy of reaction is extensive. Because on increasing the amount the value of the enthalpy also get doubles
Hence for this reaction :
Its value is -285.8 kJ for 1 mole
And here two moles are present . so the value of molar enthalpy is:
-285.8 x 2 = -571.6 kJ
Answer:
when silver articles exposed to air silver racts with Sulphur present in the atmosphere and form a black layer of silver sulphide on the surface. copper articles get tarnished by reacting with air and water. due to this, a layer is formed over copper vessels.
Answer:
2.881x10^23 atoms
Explanation:
From the studies of Avogadro's hypothesis, we discovered that 1mole of any substance contains 6.02x10^23 atoms.
Therefore 1mole of Fe contains 6.02x10^23 atoms.
Molar Mass of Fe = 56g/mol
56g of Fe contains 6.02x10^23 atoms.
Therefore, 26.8g of Fe will contain = (26.8x6.02x10^23) / 56 = 2.881x10^23 atoms
Answer:
Density = 7 g/mL
Explanation:
Given that,
Mass of a sample, m = 14 g
Volume of the sample, V = 2 mL
We need to find the density of the liquid sample. We know that the density of an object is given by :
So, the density of the liquid sample is 7 g/mL.
Answer:
The correct answer is - They are mechanical waves.
Explanation:
Atomic bombs after detonated they send a shock wave that makes a movement of particulate matter that leads to transfer of a high amount of energy that superheats the air medium that travels as a mechanical shock wave.
The shock wave that is sent out by a detonated atomic bomb is a longitudinal mechanical wave that transfers the energy to the neighboring particles of the air.
