The two reason behind the invalidity of flame test are false positive and false negative.
while performing the flame test you must have to be accurate otherwise you will get false results may be positive for some element or may be negative in case the element is present. The main reason to get the false positive and false negative is the presence and contamination of sodium.
Answer: Options (a) and (d) are the correct answer.
Explanation:
A catalyst is the substance which helps in increasing the rate of reaction.
Activation energy is the minimum amount of energy required by reactants to start the reaction. On addition of catalyst, the path of reaction changes because the energy barrier gap reduces and hence, the activation energy also decreases.
In the absence of catalyst, we need to increase the temperature so that reaction can occur quickly.
Whereas on addition of catalyst, there is no need to increase the temperature as the catalyst itself is sufficient to increase the rate of reaction. As a result, temperature should be lowered when there is addition of catalyst in the reaction.
Thus, we can conclude that catalysts can save money by essentially lowering the activation energy and temperature required.
Answer:
As the thermal energy of matter increases, its particles usually spread out, causing the substance to expand.
Explanation:
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Answer:
0.075 moles of iron oxide would be produced by complete reaction of 0.15 moles of iron.
Explanation:
The balanced reaction is:
4 Fe + 3 O₂ → 2 Fe₂O₃
By reaction stoichiometry (that is, the relationship between the amount of reagents and products in a chemical reaction), the following amounts of moles of each compound participate in the reaction:
- Fe: 4 moles
- O₂: 3 moles
- Fe₂O₃: 2 moles
You can apply the following rule of three: if by stoichiometry 4 moles of Fe produce 2 moles of Fe₂O₃, 0.15 moles of Fe produce how many moles of Fe₂O₃?
moles of Fe₂O₃= 0.075
<u><em>0.075 moles of iron oxide would be produced by complete reaction of 0.15 moles of iron.</em></u>
Answer:
V₂ = 495.89 mL
Explanation:
Given data:
Initial number of moles = 0.213 mol
Initial volume = 652 mL
Final number of moles = 0.162 mol
Final volume = ?
Solution:
V₁/n₁ = V₂/n₂
By putting values,
652 mL/0.213 mol = V₂ /0.162 mol
V₂ = 652 mL 0.162 mol /0.213 mol
V₂ = 105.62 mL.mol /0.213 mol
V₂ = 495.89 mL
