Answer is: <span>Sound waves travel faster in more dense material, and the more dense the material the louder the sound is.
</span>Sound travels approximately fifteen times faster through the metal railway tracks than through air. <span>The </span>speed of sound is faster in solid materials and slower in liquids or gases. The denser is material, t<span>he closer are the molecules to each other and the less time it takes to molecules to pass the sound to each other and sound is faster.</span>
Thank you for posting your question here at brainly. I hope the answer will help you. Feel free to ask more questions.
Below are the choices the answer is E
A. It is an animal cell because starch is the energy storing molecule in animal cells.
<span>B. It is an animal cell because starch is responsible for protein synthesizing in animal cells. </span>
<span>C. It is a plant cell because starch is responsible for protein synthesizing in plant cells. </span>
<span>D. It is a plant cell because starch is responsible for cell building in plant cells. </span>
<span>E. It is a plant cell because starch is the energy storing molecule in plant cells.</span>
Answer:
[Na₂CO₃] = 0.094M
Explanation:
Based on the reaction:
HCO₃⁻(aq) + H₂O(l) ↔ CO₃²⁻(aq) + H₃O⁺(aq)
It is possible to find pH using Henderson-Hasselbalch formula:
pH = pka + log₁₀ [A⁻] / [HA]
Where [A⁻] is concentration of conjugate base, [CO₃²⁻] = [Na₂CO₃] and [HA] is concentration of weak acid, [NaHCO₃] = 0.20M.
pH is desire pH and pKa (<em>10.00</em>) is -log pka = -log 4.7x10⁻¹¹ = <em>10.33</em>
<em />
Replacing these values:
10.00 = 10.33 + log₁₀ [Na₂CO₃] / [0.20]
<em> [Na₂CO₃] = 0.094M</em>
<em />
a) synthesis- or combination- reaction