Answer:
E = 3.035× 10-¹⁹J = 1.9eV
f = 4.58 × 10¹⁴Hz
Explanation:
wavelength = 6.55 × 10-⁷m
c = 3 × 10⁸m/s
f = ?
E = ?
a) f = c/wavelength
f = 3 × 10⁸/6.55 × 10-⁷
f = 4.58 × 10¹⁴Hz
b) E = hc/wavelength
E = 6.626×10-³⁴ × 3 × 10⁸/ 6.55 × 10-⁷
E = 3.035 × 10-¹⁹J
1ev = 1.6 × 10-¹⁹J
Therefore E = 3.035/1.6 = 1.9eV
Answer:
53.9%
Explanation:
The equation of the reaction is;
C4H6O3+C7H6O3→C9H8O4+C2H4O2
Number of moles of salicyclic acid reacted = 88.3 g/138.121 g/mol = 0.639 moles
1 mole of salicyclic acid yields 1 mole of aspirin
0.639 moles of salicyclic acid also yields 0.639 moles of asprin
Theoretical yield of asprin = 0.639 moles * 180.158 g/mol
Theoretical yield of asprin = 115.12 g
Percent yield = Actual yield/Theoretical yield * 100/1
Percent yield = 62.0 g/115.12 g * 100
Percent yield = 53.9%
look good w small changes below:
Answer:
AB is an ionic compound. The electronegativity difference between A and B is greater.
AC is an ionic compound. The electronegativity difference between A and C is greater.
BC is a covalent compound because the electronegativity difference between C and B is small.
everything else look good!
Ka of benzoic acid = 6.5 x 10⁻⁵
pKa = - log Ka = - log (6.5 x 10⁻⁵) = 4.2
Benzoic acid (C₆H₅COOH) and its conjugate base Benzoate (C₆H₅COO⁻) are considered as acidic buffer.
Using Henderson- Hasselbalch equation for calculation of pH of buffer
pH = pKa + log
= 4.2 + log (0.23) / (0.115) = 4.5