Answer:
B. 1.82(10³) seconds (1820 seconds)
Explanation:
Speed of Light: 3.00(10⁸) m/s or 3.00(10⁵) km/s
We know the distance from the Moon to Earth as 5.46(10⁸) km
We simply divide the distance by the speed of light:
We should get 1820 seconds or B. 1.82(10³) as our answer.
Answer:
helium
Explanation:
it has 8 valence electrons which fills its outer energy level making it have a stable arrangement of electrons hence least reactive
Answer:
36 KJ of heat are released when 1.0 mole of HBr is formed.
Explanation:
<em>By Hess law,</em>
<em>The heat of any reaction ΔH for a specific reaction is equal to the sum of the heats of reaction for any set of reactions which in sum are equivalent to the overall reaction:</em>
H 2 (g) + Br 2 (g) → 2HBr (g) ΔH = -72 KJ
This is the energy released when 2 moles of HBr is formed from one mole each of H2 and Br2.
Therefore, Heat released for the formation of 1 mol HBr would be half of this.
Hence,
ΔHreq = -36 kJ
36 KJ of heat are released when 1.0 mole of HBr is formed.
Answer:
Oxygen gas
Explanation:
Potassium chlorate KClO3 decomposes thermally to form potassium chloride KCl and oxygen gas is given off. This is in the presence of a catalyst, manganese iv oxide.
Hence, what is being said in essence is that when potassium chloride is heated in the presence of manganese iv oxide catalyst, oxygen is given off as the gaseous product with the formation of potassium chloride.
The chemical equation for the reaction is :
2KClO3 ——-> 2KCl + 3O2
This procedure is one of most important ways through which oxygen can be produced in the laboratory and can be used as a source of oxygen is industrial processes if on a large scale
