4.) True:
Since
P(E) = 1 - P(Ec)
P(E)+P(Ec)=1
If you think of it as the chances of you getting e or not getting e, then it's a 100% chance of either one happening.
Answer:
Explanation:
Density can be defined as mass divided by volume. But 2 objects made of the same material will have the same density regardless of their volume.
1) Chemical reaction
HCl + NaOH ---> NaCl + H2O
25.0 ml
0.150 M 0.250M
2) 50% completion => 0.025 l * 0.150 M * (1/2) = 0.001875 mol HCl consumed and 0.001875 mol HCl in solution
0.001875 mol HCl => 0.001875 mol H(+)
Volume = Volume of HCl solution + Volumen of NaOH solution added
Volume of HCl solution = 0.0250 l
Volume of NaOH = n / M = 0.001875 mol / 0.250M = 0.0075 l
Total volume = 0.0250 l + 0.0075 l = 0.0325 l
[H+] = 0.001875 mol / 0.0325 l = 0.05769 M
pH = - log [H+] = - log (0.05769) = 1.23
Answer: 1.23
3) Equivalence point
0.02500 l * 0.150 M = 0.250M * V
=> V = 0.02500 * 0.150 / 0.250 = 0.015 l
4) 1.00 ml NaOH added beyond the equivalence point
1.00 ml * 1 l / 1000 ml * 0.250 M = 0.00025 mol NaOH in excess
0.00025 mol NaOH = 0.00025 mol OH-
Volume of the solution = 0.02500 l + 0.015 l + 1.00/1000 l = 0.041 l
[OH-] = 0.00025 mol / 0.041 l = 0.00610 M
pOH = - log (0.00610) = 2.21
pH + pOH = 14 => pH = 14 - pOH = 14 - 2.21 = 11.76
Answer: 11.76
Answer:
- <em><u>Step 2 (the slow step).</u></em>
Explanation:
The rate-determining step is always the slow step of a mechanism.
That is so, because it is the slow step which limits the reaction.
Imaging that for assembling a toy you have process of three steps:
- 1. order ten pieces, which you can do in 1 minute: meaning that you can order order the pieces for 60/1 = 60 toys in 1 hour.
- 2. glue the pieces and hold the toy until the glue hardens, which takes 1 hour: meaning finishingh 1 toy in 1 hour.
- 3. pack the toy, which takes 2 minutes: meaning that you can pack 60/2 = 30 toys in one hour.
The time to glue and hold one toy until the glue hardens determines that you can assemble 1 toy in 1 hour and not 60 toys or 30 toys.
Thus, the step that determines the rate at which the reaction happens is the slowest step: step 2.
D.) closeness of a measurement to an accepted value
That is accuracy not precision.
