Answer:
D.
Explanation:
The reaction is losing potential energy, which means that the reaction is losing that energy as heat. Exothermic is the loss of energy. Therefore it will be D.
Answer: D. like dissolves like
Explanation:
The solubility of substances is governed by: Like dissolves like, which states that polar compounds are soluble in polar solvents and non polar compounds are soluble in non polar solvents.
Hydrocarbons are non polar in nature due to less difference between the electronegativities of carbon and hydrogen and thus are soluble in non polar solvents only.
Ionic compounds which are formed by elements with high electronegativity difference are polar in nature and thus dissolve in polar solvents.
Example:
in water.
Answer:
After 5 second 25% C-15 will remain.
Explanation:
Given data:
Half life of C-15 = 2.5 sec
Original amount = 100%
Sample remain after 5 sec = ?
Solution:
Number of half lives = T elapsed / half life
Number of half lives = 5 sec / 2.5 sec
Number of half lives = 2
At time zero = 100%
At first half life = 100%/2 = 50%
At second half life = 50%/2 = 25%
Thus after 5 second 25% C-15 will remain.