Telling the teacher about a chemical spill immediately
Answer:
Explanation:
2N₂O(g) → 2N₂(g) + O₂(g)
molecular weight of N₂O = 44
∆Hº = –166.7 kJ/mol
44 g of N₂O decomposes to give 166.7 kJ of heat
2.25 g of N₂O decomposes to give 166.7 x 2.25 / 44 kJ of heat
= 8.51 kJ of heat .
Answer:
Electrolysis
Explanation:
The electrolysis of water is one such experiment that shows that water is made up of hydrogen and oxygen atoms only in the ratio of 2 to 1.
In the electrolysis of water, electricity is passed through acidified water to cause it to decompose.
The electrolysis of water is also known as the electrolysis of dilute tetraoxosulphate (VI) acid.
At the cathode, H⁺ ions are discharged and hydrogen gas is liberated:
2H⁺ + 2e⁻ → H₂
At the anode, both the sulfate ion and hydroxyl ions migrate to this electrode. Only the OH⁻ is selected for preferential discharge due to its lower position in that activity series.
4OH⁻ → 2H₂O + O₂ + 4e⁻
Oxygen gas is produced at the anode.
This electrolysis demonstrates the volumetric composition of water that is, 2 volumes of hydrogen at the cathode and 1 volume of oxygen at the anode.
Answer:
Know this
1mole of a substance contains 6.022x10²³molecules
Now
8.55x10^-15moles x 6.022x10²³molecules/1mole
=5.15x10^9molecules.
Answer:
n = 5 to n = 6 absorption
n = 9 to n = 6 emission
n = 6 to n = 4 emission
n = 6 to n = 7 absorption
Explanation:
According to the Bohr's model of the atom. An electron in an atom may absorb energy and move from a lower energy level to a higher energy level. This requires absorption of energy that is equal to the energy difference between the two levels.
Similarly, an electron may move from a higher to a lower energy level, releasing energy that is equal to the energy difference between the higher and the lower level. This is known as emission.
Hence, if the electron is moving from a lower energy level to a higher energy level, an absorption has taken place, e.g n = 5 to n = 6
When an electron moves from a higher energy level to a lower energy level, an emission has taken place e.g n = 9 to n = 6
