Answer:
Group 17 elements:
Flourine (F), Chlorine (Cl), Bromine (Br), Iodine (I), and Astatine (As).
Period 2 elements:
Lithium (Li), Beryllium (Be), Boron (B), carbon (C), Nitrogen (N), Oxygen (O), flourine (F), And Neon.
We have that you can you prepare 450 ml of 1 X buffer A by adding 45ml of 10X buffer A with 405ml(450-45) of water
From the question we are told
If you have 100 ml of 10X Buffer A, how could you prepare 450 ml of 1 X buffer A
Generally the equation for the Concentration Volume relationship is mathematically given as

Therefore
You can you prepare 450 ml of 1 X buffer A by adding 45ml of 10X buffer A with 405ml(450-45) of water
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Answer:
2.40 M
Explanation:
The molarity of a solution tells you how many moles of solute you get per liter of solution.
Notice that the problem provides you with the volume of the solution expressed in milliliters,
mL
. Right from the start, you should remember that you must convert this volume to liters by using the conversion factor
1 L
=
10
3
mL
Now, in order to get the number of moles of solute, you must use its molar mass. Now, molar masses are listed in grams per mol,
g mol
−
1
, which means that you're going to have to convert the mass of the sample from milligrams to grams
1 g
=
10
3
mg
Sodium chloride,
NaCl
, has a molar mass of
58.44 g mol
−
1
, which means that your sample will contain
unit conversion
280.0
mg
⋅
1
g
10
3
mg
⋅
molar mass
1 mole NaCl
58.44
g
=
0.004791 moles NaCl
This means that the molarity of the solution will be
c
=
n
solute
V
solution
c
=
0.004791 moles
2.00
⋅
10
−
3
L
=
2.40 M
The answer is rounded to three sig figs, the number of sig figs you have for the volume of the solution.
break down food into smaller molecules the body can use; absorb molecules into blood and carry them throughout the body; eliminate wastes from the body
Answer:
Molar mass = 99 g/mol
Explanation:
Phosgene contains carbon, oxygen and chlorine atoms. Its molecular formular is; COCl2
The molar mass is given as the sum off the individual atomic mass of the elements in the compound.
Molar mass = C + O + 2Cl
Molar mass = 12 + 16 + 2(35.5)
Molar mass = 99 g/mol