This technique can be used to make pure crystals of a soluble salt.
The burette is filled with hydrochloric acid.
A known quantity of alkali (say 50 cm3 sodium hydroxide)
is released from a pipette into the conical flask.
The tap on the burette is turned open to allow
the acid to be added drop by drop into the alkali.
The alkali contains an indicator (phenolphthalein)
which is pink in an alkali and colorless in an <span>acid.
</span>
When enough acid has been added to neutralize
the alkali, the indicator changes from
pink to colorless. This is the end point of the titration.
The titration<span> can be repeated using the </span><span>same amounts
</span><span>of </span>acid<span> and </span>alkali<span> but </span>without<span> the </span>indicator.
<span>Pure salt</span> crystals<span> which are </span>free<span> from </span><span>indicator
</span><span>can then be crystallized </span><span> from the </span>neutral<span> solution.</span>
<span>Before the eruption,the fluid pressure from the rising magma (dense liquid) cracks the rocsk, the tectonic plates under the Earth's crust are moved and as a result earthquakes are caused. Manu small earthquakes in the area near a volcano hint what may happen.</span>
Hey there!:
1 mole of FeSO4 = 151.8 g/mol
25.0 g change to mole = 25.0 / 151.8
moles of FeSO4 = 0.165 moles
One mole of any substance has 6.02*10²³ units
0.165 moles to get the number of Fe ( II ) ions :
number of Fe(II) ion = 0.165 * ( 6.02*10²³ )
number of Fe ( II ) ion = 9.93*10²² units
