Plants are chlorophyll-containing photosynthetic organisms. Thus, they convert solar or radiant energy into chemical energy under the process termed as photosynthesis.
<u>Explanation:</u>
- Plants are chlorophyll-containing photosynthetic living beings. Consequently, they convert radiant energy into chemical energy under the procedure named photosynthesis.
- Except for remote ocean hydro-thermal environment, the sun is the only source for all biological systems on earth. Plants catch just 2-10 percent of the solar radiation and transmit it as chemical energy. All creatures are reliant for their nourishment on producers (plants), either directly or indirectly. So there is a stream of energy from the sun (radiant energy) to producers and then to consumers (chemical energy).
<u>False</u> is the correct answer.
Answer:
Kₐ = 6.7 x 10⁻⁴
Explanation:
First lets write the equilibrium expression, Ka , for the dissociation of hydrofluoric acid:
HF + H₂O ⇄ H₃O⁺ + F⁻
Kₐ = [ H₃O⁺ ] [ F⁻ ] /[ [ HF ]
Since we are given the pH we can calculate the [ H₃O⁺ ] ( pH = - log [ H₃O⁺ ] , and because the acid dissociates into a 1: 1 relation , we will also have [F⁻ ]. The [ HF ] is given in the question so we have all the information that is needed to compute Kₐ.
pH = -log [ H₃O⁺ ]
1.68 = - log [ H₃O⁺ ]
Taking antilog to both sides of this equation:
10^-1.68 = [ H₃O⁺ ] ⇒ 2.1 X 10⁻² M= [ H₃O⁺ ]
[ F⁻ ] = 2.1 X 10⁻² M
Solving for Kₐ :
Kₐ = ( 2.1 X 10⁻² ) x ( 2.1 X 10⁻² ) / 0.65 = 6.7 x 10⁻⁴
(Rounded to two significant figures, the powers of 10 have infinite precision )
A stove needs gas to burn (I only have one off the top of my head, sorry :/)
