Question
Give a definition of mixture?
Why air is called a mixture?
Answer:
mixture - substance made by combining two more different materials in such a way that no chemical reaction occurs.
Air is a mixture because it is composed of gases like inert gases, carbon dioxide, oxygen, nitrogen an so on. Also dust particles are present in the atmosphere so air is a mixture .
Explanation:
The bonds in the SiCl₄ molecules will be more polar.
The polarity of bonds within a molecule depends on the difference in electronegativity of the atoms that are involved in the bond. Chlorine is a more electronegative atom than iodine. Therefore, the electrons in the Si-Cl bond will be more concentrated near the Cl, creating polarity in the bond. Iodine is not as electronegative, so it will not result in a very polarized Si-I bond
Answer : Normally in any chemical reaction, if the enthalpy change i.e. ΔH is positive which means it is greater than zero then it can be called as an Endothermic Reaction.
Whereas, the system under study is absorbing heat that is produced during the reaction. So if ΔH is found to be positive then it can be called as endothermic reaction.
The answer is d. particles move from an area of high concentration to low concentration.
Answer:
Mass = 255 g
Explanation:
Given data:
Number of moles of nitrogen = 7.5 mol
Mass of ammonia formed = ?
Solution:
Chemical equation:
3H₂ + N₂ → 2NH₃
Now we will compare the moles of nitrogen and ammonia.
N₂ : NH₃
1 : 2
7.5 : 2/1×7.5 = 15
Mass of ammonia:
Mass = number of moles × molar mass
Mass = 15 mol × 17 g/mol
Mass = 255 g
