Answer:
Because it can cause health problems or injuries to our sense organs.
Explanation:
Chemicals in the laboratory are made up of different constituents, which may be dangerous or injurious to health. This is the reason why safety measures or precautions have to be taken when working in the laboratory. One of those safety measures is that "one should never use taste, touch, or smell to identify an unknown chemical".
This is so because a chemical that is unknown amounts to the fact that what such chemical contains is unknown, hence, the chemical might have the ability to cause harm or injuries to the sense organ. For example, a conc. acid that is tasted will burn the tongue etc.
Answer:
Infrared radiation → A) used to detect the location of objects
Microwaves → D) Used in radar and to heat food
Ultraviolet light → C)Given off by very hot objects, such as the sun Heat from warm objects
Visible light → B) All the radiation humans can see, ranging from red to violet
Explanation:
Microwaves have magnetic waves with very long lengths, greater than that of infrared light. These waves are produced through vibrations that produce heat, as the microwave is turned on, which allows the food to be heated. These waves are also used to provide communication on some types of devices.
Infrared radiation is a type of non-ionizing radiation that has a low frequency and therefore cannot be visualized, since it is not within a visible electromagnetic spectrum, having a frequency lower than red. It can be used to detect the licalization of objects and does not pose a health risk.
Ultraviolet radiation is extremely harmful to our body. It is characterized by radiation with very small wavelengths, less than 400nm. This type of radiation can be released by the sun and ultraviolet lamps.
Visible light refers to the simplest form of electromagnetic wave and covers all the radiation that our eyes can see, allowing different colors to be seen in the objects we observe according to the reorganization of atoms and molecules.
Remember that in this case pressure is equal to 1.00 atm and temperature is equal to 273.15K. So,
P
V
=
n
R
T
→
n
=
P
V
R
T
=
1.00
a
t
m
⋅
7.0
L
0.082
a
t
m
⋅
L
m
o
l
⋅
K
⋅
273.15
K
=
0.31
Since we know hydrogen's molar mass (
2.0
g
m
o
l
), we can determine the mass
m
H
2
=
n
⋅
m
o
l
a
r
.
m
a
s
s
=
0.31
m
o
l
e
s
⋅
2.0
g
m
o
l
=
0.62
g
If indeed you are dealing with STP, remember that, under these conditions, 1 mole of any ideal gas occupies
22.4
L
. So,
n
=
V
V
m
o
l
a
r
=
7.0
L
22.4
L
=
0.31
moles
And, once again,
m
=
0.31
⋅
2.0
=
0.6
Answer:
The emf of the electrochemical cell has been calculated to be <u>3.364.</u>
in order to calculate the emf we need to apply Nernst equation.
The emf has been the potential of the cell in the reaction with the change in the electrons in the reaction. The emf of the cell has been given by the Nernst equation as -
emf= E⁰ cell - 0.059/n. log 1/concentration
Computation for the emf of the cell
The given cell has the number of electrons transfer, n= 2
The concentration of Pb2= 0.57 M
The concentration of H= 0.090 M
The cell potential of the reaction has been= -0.126
Substituting the values for the emf of the cell:
emf= -0.126- 0.059/2 * log 1/ [0.57]x [0.090] ²
emf= 1.555* 2.337
emf=3.634 v
The emf of the electrochemical cell has been calculated to be 3.634 v.
Learn more about emf here-
brainly.com/question/9425530
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