Part A
75.0 mL of 0.10 M HF; 55.0 mL of 0.15 M NaF
This combination will form a buffer.
Explanation
Here, weak acid HF and its conjugate base F- is available in the solution
Part B
150.0 mL of 0.10 M HF; 135.0 mL of 0.175 M HCl
This combination cannot form a buffer.
Explanation
Here, moles of HF = 0.15 x 0.1 = 0.015 moles
Moles of HCl = 0.135 x 0.175 = 0.023
Since HCl is a strong acid and the number of HCl is higher than HF. This prevents the dissociation of HF and the conjugate base F- will not be available in the solution
Part C
165.0 mL of 0.10 M HF; 135.0 mL of 0.050 M KOH
This combination will form a buffer.
Explanation
Moles of HF = 0.165 x 0.1 = 0.0165 moles
Moles of KOH = 0.135 x 0.05 = 0.00675 moles
Moles of KOH is not sufficient for the complete neutralization of HF. Thus weak acid HF and its conjugate base F- is available in the solution and form a buffer
Part D
125.0 mL of 0.15 M CH3NH2; 120.0 mL of 0.25 M CH3NH3Cl
This combination will form a buffer
Explanation
Here, weak acid CH3NH3+ and its conjugate base CH3NH2 is available in the solution and form a buffer
Part E
105.0 mL of 0.15 M CH3NH2; 95.0 mL of 0.10 M HCl
This combination will form a buffer
Explanation
Moles of CH3NH2 = 0.105 x 0.15 = 0.01575 moles
Moles of HCl = 0.095 x 0.1 = 0.0095 moles
Thus the HCl completely reacts with CH3NH2 and converts a part of the CH3NH2 to CH3NH3+. This results weak acid CH3NH3+ and its conjugate base CH3NH2 is in the solution and form a buffer
D has a total of four significant figures.
Molar mass <span>CH2BrCH2Br = 188.0 g/mol
1 mole ---------- 188.0 g
</span>0.500 moles ----- ?
mass = 0.500 * 188.0 / 1
= 94.0 g
Answer C
hope this helps!
Explanation:
Solubility is determined by the principle , "like dissolves like" .
i.e. , if a compound is polar then it will dissolve in a polar compound only , and
if a compound is non - polar then it will dissolve in a non - polar compound only .
Hence , from the question ,
Water is a polar molecule , and hence it will dissolve only the polar molecule , i.e. , from the given options the polar molecule is , iii. K₂SO₄
Hexane , is a non - polar molecules , hence it will dissolve only the non polar molecule , i.e. , from the given options the non polar molecule is i. Butane .
Steak is a meat and juice is a liquid
