Given:
Half life(t^ 1/2) :30 years
A0( initial mass of the substance): 200 mg.
Now we know that
A= A0/ [2 ^ (t/√t)]
Where A is the mass that remains after t years.
A0 is the initial mass
t is the time
t^1/2 is the half life
Substituting the given values in the above equation we get
A= [200/ 2^(t/30) ] mg
Thus the mass remaining after t years is [200/ 2^(t/30) ] mg
Molar mass H₃PO₄ = 98.0 g/mol
1 mole ----- 98.0 g
? mole ------ 30.0 g
moles = 30.0 * 1 / 98.0
= 0.306 moles
hope this helps!
The salt causes the water to freeze at a lower temperature. When a solute, aka salt, is introduced to the system, the freezing point is lowered. This makes the water freeze at a lower temperature.
