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.
Mechanical energy is the sum of potential energy and kinetic energy.
The balanced equation for the reaction between NaOH and HCl is as follows
NaOH + HCl ---> NaCl + H₂O
stoichiometry of NaOH to HCl is 1:1
number of NaOH moles reacted - 0.250 mol/L x 0.0200 L = 0.005 mol
therefore number of HCl moles reacted - 0.005 mol
molarity of given HCl solution - 0.100 M
number of HCl moles in 1 L - 0.100 mol
then 0.005 mol of HCl in - 0.005 mol / 0.100 mol/L = 50.0 mL
volume of HCl required is 50.0 mL
First one is A the second one is A as well
The correct answer would be D: Physical properties can be observed without changing the identity of a substance
