You have to use the Henderson-Hasselbalch equation. Keep in mind that because the Pka is given the equation changes form slightly:
PH = Pka + log[acid/base]
Step 1 (Figure out the concentrations):
0.282 M of Acid (C6H5OOH) - 0.150 M = 0.132 M of acid
0.282 M of Base (C6HCOO) + 0.150 M = 0.432 M of bas3
Step 2 (Plug into equation):
PH = Pka + log[acid/base]
PH = 4.20 + log[0.132 M/0.432 M]
PH = 3.69
Answer:
That unknown substance is water
Explanation:
I believe it's answer #3. Logically, at least.
You can test #1 through trial and error.
You can experiment #2 also through trial and error.
You cannot test #3 through trial and error, because that would be catastrophic.
You can test #4 through a survey and individual study and data collection.
We can use the formula P=IV to calculate the current, where “P” is power (measured in watts), “I” is current (measured in Amps), and “V” is voltage. Simply plug and solve:
P = IV
(3.5 Watts) = I(120 volts)
I = 0.0292 Amps
The current flowing through the bulb is approximately 0.0292 Amps.
Hope this helps!
I think convergent but could be wrong