Answer:
Titrations. Because a noticeable pH change occurs near the equivalence point of acid-base titrations, an indicator can be used to signal the end of a titration. When selecting an indicator for acid-base titrations, choose an indicator whose pH range falls within the pH change of the reaction.
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Answer:
D
Explanation:
The amount of energy released or absorbed is equal the product of the mass, the specific heat capacity and the temperature change. The temperature change being the difference between the final and initial temperature.
Q = mc∆T
Q = heat energy (Joules, J) m = mass of a substance (kg) c = specific heat (units J/g∙K)
∆ is a symbol meaning "the change in" ∆T = change in temperature (Kelvins, K)
From the data provided in the question, we can deduce that:
Q = 16.7KJ = 16,700J
m = 225g
c = 1.74J/g.k
For the temperature, let the final temperature be f. This means our ∆T = f - 20
16,700 = 225 * 1.74 * (f - 20)
16700 = 391.5 (f - 20)
f - 20 = 16700/391.5
f - 20 = 42.7
f = 20 + 42.7 = 62.7
You can use the mass of neuron divided by the mass of conversion factor: 1.67*10^(-25)/(1.66054*10^(-24))≈1 amu. So the answer is 1 amu.
