Answer:
They frequency = 3.9 * 10^16 Hz
The amount of energy E = 2.58 *10^-17 J
Explanation:
Step 1: Data given
wavelength is 7.67 * 10^-7 cm
Step 2: Calculate the frequency
f = c / λ
⇒ with λ = the wavelength in nm = 7.67 nm
⇒ with c = the speed of light = 3.00 * 10^8 m/s
⇒ f = the frequency = TO BE DETERMINED
f = (3.00 * 10^8 m/s) / 7.67 * 10^-9 m
f = 3.9 * 10 ^16 /s = 3.9 * 10^16 Hz
They frequency is 3.9 * 10^16 Hz
Step 3: Calculate the amount of energy
E = h
*f
⇒ with E = the amount of energy (in joule)
⇒ h = Planck's constant = 6.626 *10^-34 J*s
⇒ with f = the frequency
E = 6.626 *10^-34 J*s * 3.9 * 10^16 Hz
E = 2.58 *10^-17 J
45.2 g coconut oil containing
Answer:
Molarity = 0.809 M
mole fraction = 0.047
Explanation:
The complete question is
Calculate the molarity and mole fraction of acetone in a 1.09-molal solution of acetone (CH3COCH3) in ethanol (C2H5OH). (Density of acetone = 0.788 g/cm3; density of ethanol = 0.789 g/cm3.) Assume that the volumes of acetone and ethanol add.
Solution -
Solution for molarity:
1.09-molal means 1.09 moles of acetone in 1.00 kilogram of ethanol.
1)
Mass of 1.09 mole of acetone
= 1.09 mol x 58.0794 g/mol = 63.306 g
Density of acetone = 0.788 g/cm3
Thus, volume of 1.09 moles of acetone = 63.306 g/0.788 g/cm3 = 80.34 cm3
For ethanol
1000 g divided by 0.789 g/cm3 = 1267.427 cm3
Total volume of the solution = Volume of acetone + Volume of ethanol = 80.34 cm3 + 1267.427 cm3 = 1347.765 cm3 = 1.347 L
a) Molarity:
1.09 mol / 1.347 L = 0.809 M
Mole Fraction
a) moles of ethanol:
1000 g / 46.0684 g/mol = 21.71 mol
b) moles of acetone:
1.09 / (1.09 + 21.71) = 0.047
