The energy utilized by top-level predators comes from their prey. Explanation: Top-level predators are at the apex of the food chain, dominating it through their hunting methods. Examples include wolves and lions, which occupy the highest trophic levels within their respective food webs, deriving their energy from their prey. They are carnivores, feeding on secondary consumers.
Response:
Unfiltered polluted water appears unclear and has a yellowish tint. The filtered polluted water is clear, albeit with a slight yellow hue. The pH levels exceed the tolerable range for organism survival. From these observations, it can be inferred that even if water seems clean, it may not be safe and could still pose risks to living organisms.
Answer:
189.2 KJ
Explanation:
Provided Data
light wavelength = 632.8 nm
Convert nm to meters
1 nm = 1 x 10⁻⁹
632.8 nm = 632.8 x 1 x 10⁻⁹ = 6.328 x 10⁻⁷m
What is the energy of 1 mole of photons?
Solution
Used Formula
E = hc/λ
where
E = energy per photon
h = Planck's Constant
Planck's Constant = 6.626 x 10⁻³⁴ Js
c = speed of light
speed of light = 3 × 10⁸ ms⁻¹
λ = wavelength of light
Insert values into the equation
E = hc/λ
E = 6.626 x 10⁻³⁴ Js ( 3 × 10⁸ ms⁻¹ / 6.328 x 10⁻⁷m)
E = 6.626 x 10⁻³⁴ Js (4.741 x 10¹⁴s⁻¹)
E = 3.141 x 10⁻¹⁹J
3.141 x 10⁻¹⁹J indicates the energy for a single photon
Next, we need to determine the energy for 1 mole of photons
It is known that
1 mole contains 6.022 x10²³ photons
Consequently,
Energy for one mole of photons = 3.141 x 10⁻¹⁹J x 6.022 x10²³
Energy for one mole of photons = 1.89 x 10⁵ J
Now convert J to KJ
1000 J = 1 KJ
1.89 x 10⁵ J = 1.89 x 10⁵ /1000 = 189.2 KJ
Thus,
the energy for one mole of photons is 189.2 KJ
Answer: 0.0164 molar concentration of hydrochloric acid in the resulting solution.
Explanation:
1) Molarity of 0.250 L HCl solution: 0.0328 M
The amount of HCl in the 0.250 L solution = 0.0082 moles
2) Molarity of 0.100 L NaOH solution: 0.0245 M
The amount of NaOH in the 0.100 L solution = 0.00245 moles
3) Determining the concentration of hydrochloric acid in the final solution.
0.00245 moles of NaOH will neutralize 0.00245 moles of HCl from the original 0.0082 moles of HCl.
The total volume of the mixture becomes 0.100 L + 0.250 L = 0.350 L
Remaining moles of unreacted HCl = 0.0082 moles - 0.00245 moles = 0.00575 moles
Concentration of the remaining HCl:
0.0164 molar concentration of hydrochloric acid in the resulting solution.
Solution:
The molecular formula is PbSO₄, indicating lead sulfate
Option c.
Explanation:
The percentage makeup shows that in 100 g of this compound, there are:
68.3 g of Pb, 10.6 g of S, and (100 - 68.3 - 10.6) = 21.1 g of O
To find the moles of each element, we divide by their molar masses:
68.3 g Pb / 207.2 g/mol = 0.329 moles Pb
10.6 g S / 32.06 g/mol = 0.331 moles S
21.1 g O / 16 g/mol = 1.32 moles O
Next, we find the mole ratio by dividing each by the smallest number of moles:
0.329 / 0.329 = 1 Pb
0.331 / 0.329 = 1 S
1.32 / 0.329 = 4 O
Thus, the molecular formula is PbSO₄, representing lead sulfate.
