Answer:
The group given the sugar pills.
Explanation:
The control group is the ones given sugar pills because they did not get the experimental aspirin
Answer:
Explanation:
(4) A does not burn in air, and B does burn in air is your answer. Flammability is a chemical property while the rest of these are physical properties.
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A. Plastic is a good insulator.
Answer:
The pH and pOH of a 2.2*10⁻³ HBr solution is 2.66 and 11.34 respectively.
Explanation:
pH - short for hydrogen potential - is a measure of the acidity or alkalinity of a solution. So the pH is a parameter that indicates the concentration of hydrogen ions [H]⁺ that exist in a solution.
The pH is expressed as the negative base 10 logarithm of the hydrogen ion concentration. This is represented by:
pH= - log [H⁺]
pH is measured on a scale of 0 to 14. On this scale, a pH value of 7 is neutral, which means that the substance or solution is neither acidic nor alkaline. A pH value of less than 7 means that it is more acidic, and a pH value of more than 7 means that it is more alkaline.
HBr is a strong acid. Then, in aqueous solution it will be totally dissociated. So the proton concentration is equal to the initial concentration of acid:
[H⁺]= [HBr]= 2.2*10⁻³ M
So:
pH= - log (2.2*10⁻³)
pH= 2.66
On the other hand, pOH is a measure of the concentration of hydroxyl ions in a solution. The sum of pH and pOH equals 14:
pH + pOH= 14
2.66 + pOH= 14
pOH= 14 - 2.66
pOH= 11.34
<u><em>The pH and pOH of a 2.2*10⁻³ HBr solution is 2.66 and 11.34 respectively.</em></u>
You need to use Avogadro's constant to convert from atoms of carbon to moles of carbon.
1.71*10^24 atoms C * (1 mole/6.022*10^23 atoms) = 2.84 moles of carbon
