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Topic:
Reaction Kinetics
Question:
For homogeneous catalysis reaction between liquids, the catalyst should be of which form?
Options:
- Solid
- Liquid
- Gas
- Can be any of the above
Correct Answer:
Liquid
Explanation:
In chemistry, homogeneous catalysis is a sequence of reactions that involve a catalyst in the same phase as the reactants. Phase here refers to solid, liquid, vs gas. Most commonly, a homogeneous catalyst is co-dissolved in a solvent with the reactants.
Topic:
Solutions
Question:
If we have 450g of a NaCL solution that is 35 NaCL w/w %. What is the mass of NaCL?
Options:
- 128.5 g
- 129.5 g
- 157.5 g
- 131.5 g
Correct Answer:
157.5 g
Explanation:
% by weight = (Mass of solute/Mass of solution) * 100
35 = (X/450) *100
X = 35 * 450/100 = 157.5 g
Topic:
Basics of Chemistry
Question:
Non-stoichiometric compounds are formed by:
Options:
- Only alkali metals
- Only transition elements
- Only noble gases
- None of the above
Correct Option:
Only transition elements
Explanation:
Binary transition metal compounds, such as the oxides and sulfides, are usually written with idealized stoichiometry’s, such as FeO or FeS but these compounds are usually cation deficient and mostly never contain a 1:1 cation:anion ratio. Thus a substance such as ferrous oxide is actually a nonstoichiometric compound with a range of compositions.