Answer:
All of the above
Explanation:
Their all chemical change
 
        
             
        
        
        
Lowery-Bronsted theory is applied here. Acc. to this theory Base accepts protons and Acids donate proton.
Part 1: 
Aniline is less basic than ethylamine because the lone pair on nitrogen (which accepts proton) is not localized. It resonates throughout the conjugated system of phenyl ring. Hence due to unavailability of electrons for accepting proton it is less basic compare to ethylamine. In ethyl amine the lone pair of electron is localized and available to abstract proton.
Part 2:
In this case the alkyl groups attached to -NH₂ (in ethylamine) and -O⁻ (in ethoxide are same (i.e. CH₃-CH₂-). Ethoxide is more basic than ethylamine because ethoxide is a conjugate base of ethanol (pKa value of ethanol = 15.9 very weak acid) and the conjugate base of weak acid is always a strong base. Secondly, the oxygen atom more Electronegative than Nitrogen atom can attract more electron cloud from alkyl group as compared to Nitrogen in ethylamine. Hence, oxygen in ethoxide attains greater electron cloud than the nitrogen in ethylamine. Therefore, it is more basic than ethylamine.
 
        
        
        
For the first question the answer is 
The "s" orbital can only hold a maximum of two electrons. ... Elements in the each group have the same number of valence electrons. Why is hydrogen set apart by itself? Hydrogen does not belong to a single group b/c it can be considered an alkali metal, but it is also a gas.
 
        
             
        
        
        
Answer:
0.805 M.
Explanation:
Hello!
In this case, since the molarity of a solution is computing by dividing the moles of solute over the volume of solution in liters (M=n/V), for 15.0 g of potassium chloride (74.55 g/mol) we compute the corresponding moles:

Next, since the volume is 0.2500 in liters, the molarity turns out:

Best regards!