Answer:
a. 2.44 nm
b. 15.33 nm²
Explanation:
a. Calculate the thickness (in nm) of the surface film
Since the volume of a teaspoon equals V = 4.93 cm³ and the area of the oil film is half an acre = 1/2 × 4046.86 m² = 2023.43 m²
The volume of the oil film, V' equals the volume of the oil in the teaspoon, V
V' = Ah where A = cross-sectional area of oil film = 2023.43 m² = 2023.43 × 10⁴ cm² and h = height of oil film
So, V' = V
Ah = V
h = V/A
= 4.93 cm³/2023.43 × 10⁴ cm²
= 0.00244 × 10⁻⁴ cm
= 2.44 × 10⁻⁷ cm
= 2.44 × 10⁻⁷ cm × 1m/100 cm
= 2.44 × 10⁻⁹ m
= 2.44 nm
b. The surface area (in nm2) occupied by an oleic acid molecule on water.
Since the height of the oil film equals the diameter of the oil molecule, and the molecule is assumed to be a sphere of radius, r. Its surface area is thus A = 4πr²
r = h/2 = 2.44 nm/2 = 1.22 nm
A = 4πr²
A = 4π(1.22 nm)²
A = 4.88π nm²
A = 15.33 nm²
I think this is True.
Aerobic organisms are more energy-efficient than anaerobic.
~ Good luck!
Answer:
9028.8 J
Explanation:
The equation for working out the amount of thermal energy required is q = m c Δ T , where q is the amount of energy, m is the mass being heated up in grams, c is the specific heat capacity of what you're heating up in joules per gram per kelvin, and Δ T is the change in temperature in Kelvin.(Change in temperature will always give the same value,no matter Celsius or Kelvin)
mass = 27g, assuming specific heat capacity of water is 4.18 J/g*K, and the change in temperature is 90-10(=80) , the energy needed to raise : 80 × 27 × 4.18 = 9028.8 J
<span>Heterogenous mixtures are those which are seperable by physical means. These mixtures do not have uniform properties throughout the substance. For example, blood is a heterogenous mixture because it can be seperated into its components via a physical change (centrifugation). </span>