The answer is Fire symbol 1
That is Fire symbol 1, signifies ammunition with a mass explosion.
The symbol can be seen in the image attached.
This symbol includes these :
1. Do not use fire fighting unless rescue attempt is planned.
2. If person's safety is in danger, use cover.
This fire symbol 1 signifies ammunition with a mass explosion.
The idea here is that you need to figure out how many moles of magnesium chloride,
MgCl
2
, you need to have in the target solution, then use this value to determine what volume of the stock solution would contain this many moles.
As you know, molarity is defined as the number of moles of solute, which in your case is magnesium chloride, divided by liters of solution.
c
=
n
V
So, how many moles of magnesium chloride must be present in the target solution?
c
=
n
V
⇒
n
=
c
⋅
V
n
=
0.158 M
⋅
250.0
⋅
10
−
3
L
=
0.0395 moles MgCl
2
Now determine what volume of the target solution would contain this many moles of magnesium chloride
c
=
n
V
⇒
V
=
n
c
V
=
0.0395
moles
3.15
moles
L
=
0.01254 L
Rounded to three sig figs and expressed in mililiters, the volume will be
V
=
12.5 mL
So, to prepare your target solution, use a
12.5-mL
sample of the stock solution and add enough water to make the volume of the total solution equal to
250.0 mL
.
This is equivalent to diluting the
12.5-mL
sample of the stock solution by a dilution factor of
20
.
Phenolphthalein<span> is often used as an indicator in acid–base titrations. For this application, it </span>turns<span> colorless in acidic solutions and </span>pink<span> in basic solutions. </span>Phenolphthalein<span> is slightly soluble in water and usually is dissolved in alcohols for use in experiments.
</span>
Democritus *suggested* the existence of the atom, that everything was made up of tiny particles, but wasn't really able to get more specific than that. Dalton also theorized that everything was made up of indivisible particles, but went further basing his theory on actual scientific principles, such as the Law of Conservation of Mass and the Law of Constant Composition. He also said that atoms weren't created or destroyed in a chemical reaction, just rearranged. There's more to it than that, but basically, Dalton's theory was based more on science while Democritus' theory was too general to be useful in chemical situations.
