Answer:
A) positive; added
Explanation:
Based on the reaction:
2NaHCO3(s) + 129kJ → Na2CO3(s) + H2(g) + CO2(g)
<em>2 moles of NaHCO3 requires 129kJ to produce 1 mole of Na2CO3, 1 mole of H2 and 1 mole of CO2.</em>
<em />
That means, the energy must be added being, thus, an exothermic reaction. The exothermic reactions have ΔH >0.
Thus, right answer is:
A) positive; added
Besides producing hydrogen ions in water, all Arrhenius acids have a few things in common. They have pH values anywhere from 0 up to 7, they taste and smell sour and they will turn pH paper pink, red, or orange.
<h3>What Arrhenius acids?</h3>
A substance that raises the concentration of H+ ions in an aqueous solution is known as an Arrhenius acid. Traditional Arrhenius acids are highly polarized covalent substances that dissociate in water to form an anion (A-) and the cation H+.
Aqueous Arrhenius acids have distinguishing characteristics that serve as a useful definition of an acid. Acids can turn blue litmus red, produce aqueous solutions with a sour taste, and react with bases and some metals (like calcium) to generate salts. The Latin word acidus/acre, which means "sour," is where the word acid originates.
Although the precise definition solely refers to the solute, the term "acid" is sometimes used to refer to an aqueous solution of an acid that has a pH lower than 8.
To learn more about Arrhenius acids from the given link:
brainly.com/question/22095536
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Are you referring to DNA?
At STP
1L O₂ → 2L CO₂
xL O₂ → 5.0L CO₂
x=2.5 L
