First one. Coefficients are numbers that balance the equation, just like if there is an equation in math where 1=2, you need to multiply 1 by 2 to make that equation true. That's a nice jingle you can remember.
Answer:
The concentration is 50,8 % w/v and radio strengths = 1,96.
Explanation:
Phenobarbital sodium is a medication that could treat insomnia, for example.
2,0 M of Phenobarbital sodium means 2 moles in 1L.
The concentration units in this case are %w/v that means 1g in 100 mL and ratio strengths that means 1g in <em>r</em> mL. Thus, 2 moles must be converted in grams with molar weight -254 g/mole- and liters to mililiters -1 L are 1000mL-. So:
2 moles × 
= 508 g of Phenobarbital sodium.
1 L ×
= 1000 mL of solution
Thus, % w/v is:
× 100 = 50,8 % w/v
And radio strengths:
= 1,96. Thus, you have 1 g in 1,96 mL
I hope it helps!
In a chemical reaction,
the limiting reagent is the chemical being used up while the excess reactant is
the chemical left after the reaction process.
Before calculating the limiting
and excess reactant, it is important to balance the equation first by stoichiometry.
C25N3H30Cl + NaOH = C25N3H30OH + NaCl
Since the reaction is already balanced, we can now identify which
is the limiting and excess reagent.
First, we need to determine the number of moles of each chemical
in the equation. This is crucial for determining the limiting and excess reagent.
<span>Assuming that there is the
same amount of solution X for each reactant</span>
1.0 M NaOH ( X ) = 1.0
moles NaOH
1.00 x 10-5 M C25N3H30Cl
( X ) = 1.00 x 10-5 moles C25N3H30Cl
<span>The result showed that the
crystal violet has lesser amount than NaOH. Thus, the limiting reactant in this
chemical reaction is crystal violet and the excess reactant is NaOH.</span>
