To obtain a resolution of 1.50, how many theoretical plates must
a packed column have for...
To obtain a resolution of 1.50, how many theoretical plates must
a packed column have for two peaks which elute at 5.42 and 5.63
minutes, where tm = 1.00 min? With a resolution of 1.50, are these
peaks considered to be resolved?
An HPLC column received from a manufacturer was specified to
have 4000 plates measured under standard conditions with a test
compound. When the customer repeated the test she found only 1500
plates, despite a symmetrical Gaussian peak shape. What might
account for this?
a. How
many people must be surveyed to obtain the percent of the
population that has health insurance to within 4% with
90% confidence? b. How
many subjects must be sampled to estimate the mean annual expense
of a family on cell phones to within $4 with
99% confidence. Assume the population standard deviation is $9.
[7] How many MB of video memory is required to display an
image with a resolution of 1,920 x 1,080 pixels and 65,536 colors
(2^16colors)? However, 1 [MB] = 1,000 [kB] and 1 [kB] = 1,000
(B).
[8] What is the amount of video memory required to display an
image with a resolution of 1,600 x 1,200 pixels and 65,536 colors
(2^16 colors)? However, 1 [MB]= 1,000 [kB], 1 (kB] = 1,000
(B).
[9] Minimum required for video distribution at...
1. How many grams of solid sodium
nitrite should be added to 1.50 L
of a 0.106 M nitrous acid
solution to prepare a buffer with a pH of
4.058?
grams sodium nitrite = _____
g.
2. How many grams of solid sodium
cyanide should be added to 1.00 L
of a 0.196 M hydrocyanic acid
solution to prepare a buffer with a pH of
10.140?
grams sodium cyanide =
_____g.
1) How many grams of solid ammonium
chloride should be added to 1.50
L of a 0.273 M ammonia solution
to prepare a buffer with a pH of 8.540 ?
2) How many grams of solid sodium
hypochlorite should be added to
1.00 L of a 0.239 M
hypochlorous acid solution to prepare a buffer
with a pH of 8.109 ?
1. How many grams of solid sodium nitrite should be added to
1.50 L of a 0.159 M nitrous acid solution to prepare a buffer with
a pH of 4.126 ?
grams sodium nitrite = _____g
2. How many grams of solid sodium
nitrite should be added to 1.00 L
of a 0.134 M nitrous acid
solution to prepare a buffer with a pH of 4.123
?
grams sodium nitrite =
_____g.