Answer: C, Lowering the temperature
Explanation: Gradpoint
NaCl
H2S
C2H4
N2(g) + 3H2(g)2NH3(g)
What is the percentage yield when 60 kg of ammonia is produced from 60 kg of hydrogen?
A
5.9%
B
17.6%
с
35.3%
D
50.0%
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
B. Catalyst B
C. Catalyst C
D. Catalyst D
Answer:
B. Catalyst B
Explanation:
Explanation: Enzymes are complex proteins that have a very specific shape. Just as a key fits a lock and allows it to open, the active site of the enzyme fits the reactants, allowing them to meet at the right orientation to form new chemical bonds. The shape of catalyst B is the best fit to the given reactants and product. The presence of catalysts allows reactions to proceed at much lower energy levels than without, as high-energy collisions between molecules are no longer necessary.