Answer:
B
17.6%
Explanation:
1. Percentage yield = (Actual yield/theoretical yield) x 100
2. You know actual yield of ammonia (60kg) so you need to work out theoretical yield.
3. mols of hydrogen = m/mr = 60,000/2 = 30,000 mols.
4. 3:2 ratio so (30,000/3) x 2 = 20,000 mols of Ammonia.
5. Therefore mass of ammonia = mr x mols = 20,000 x 17 = 340,000 grams
6. So percentage yield is (60,000/340,000) x 100 = 17.6
(2) Ca, Mg, Be (4) Sr, Ra, Ba
150 J
B.
270 J
C.
1350 J
D.
2250 J
The formula that can be applied in this problem is W = Fd where W is work, F is the force and d is distance. You have 450N and 3m, all you have to do is to multiply it.
W = Fd
W = (450N) (3m)
W = 1350J
The answer is letter C.
The exothermic step in ozone reactions is O₃ → O₂ + O. The most endothermic step is 3O₂ → 2O₃ because it needs energy to break the double bond in O₂. Ozone can be decomposed by light with a longer wavelength because the O-O bond in ozone is weaker than the O=O double bond in oxygen.
The reactions mentioned are involved in the ozone production and destruction in the atmosphere. The first reaction : 3O₂ → 2O₃ is an endothermic process as it needs energy (in the form of UV light) to break the double bond in O₂ and form O₃. However, the reaction : O₃ → O₂ + O is exothermic. It involves the breaking of the weaker bond in O3 and formation of a stronger O₂ molecule and oxygen atom. Thus, the answer to part (a) would be the step O₃ → O₂ + O.
For part (b), the most endothermic step would again be 3O₂ → 2O₃. Lastly, the explanation of why ozone can be decomposed by light with a longer wavelength than that required to decompose oxygen is because the O-O bond in ozone is weaker than the O=O double bond in oxygen. Hence, it requires less energy (or light of longer wavelength) to break the O-O bond in ozone, leading to its decomposition.
For more such questions on ozone reactions, click on:
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B. appetite.
C. culture.
D. activity level.
You can find water stored as a gas in the atmosphere.
You can find water stored as a solid in the Glaciers.
For PLATO Users
The Cycle And Movements Of Water Link Below