Answer:
The correct answer is 0.10.
Explanation:
Based on the given question, in a buffer solution of 1 liter, the molarity of acetic acid is 1.420 M and the molarity of sodium acetate is 0.67. The pKa value of acetic acid given is 4.74, now the pH of buffer is,
pH of buffer = pKa + log ([CH3COONa]/[CH3COOH])
= 4.74 + log (0.67/1.420)
= 4.74 + (-0.326)
= 4.41
Now 0.10100 mol of HCl is added, the HCl reacts with sodium acetate to give,
CH3COONa + HCl = CH3COOH + NaCl
Now the concentration of CH3COONa becomes = 0.67-0.101 = 0.57 M, and the new concentration of CH3COOH becomes = 1.420 + 0.101 = 1.52 M
Now the new pH will be,
= pKa + log (0.57/1.52)
= 4.74 + (-0.426)
= 4.31
The pH change is 4.41-4.31 = 0.10
During the development of a scientific theory, numerous scientific experiments are carried out through different approaches. A theory holds true as long as no experiment disproves a theory.
This experiment showed that when testing a theory with a new approach, it is possible that it may be disproven, meaning scientists should not settle for any explanation for a natural phenomenon that is not completely explained; instead, they should continue to investigate and hypothesize to improve their understanding of the phenomenon.
Answer:
Molarity of Sr(OH)₂ = 0.47 M
Explanation:
Given data:
Volume of Sr(OH)₂ = 15.0 mL
Volume of HCl = 38.5 mL (0.0385 L)
Molarity of HCl = 0.350 M
Concentration/Molarity of Sr(OH)₂ = ?
Solution:
Chemical equation:
Sr(OH)₂ + 2HCl → SrCl₂ +2H₂O
Number of moles of HCl:
Molarity = number of moles/ volume in L
0.350 M = number of moles/0.0385 L
Number of moles = 0.350 mol/L× 0.0385 L
Number of moles = 0.0135 mol
Now we will compare the moles of HCl with Sr(OH)₂.
HCl : Sr(OH)₂
2 : 1
0.0135 : 1/2×0.0135 = 0.007 mol
Molarity/concentration of Sr(OH)₂:
Molarity = number of moles / volume in L
Molarity = 0.007 mol /0.015 L
Molarity = 0.47 M
Answer:
19.39mph
Explanation:
To calculate speed, the formula; distance (d)/time(t) is used.
In this question, a distance of 40yards and a time of 4.22seconds is given. We need to convert the distance to miles and time to hours.
If 3600s = 1 hr
Then 4.22s will be 4.22/3600 hours
= 0.001172hours.
If 1760 yd = 1 mile
Then 40 yd will be 40/1760 miles
= 0.02272miles
Hence, the speed in miles per hour (mph) = 0.02272miles ÷ 0.001172hours
= 0.02272 ÷ 0.001172
= 19.38566
= 19.39
Therefore, the speed of the player is 19.39 miles per hour (mph).
