So you have to multiply 786,3 times 0.98 to get the mass the mass is 770.57 if u round its 770.6 or 771
I disagree with the answer pick of D. If you have a neutral pH 7 solution and you proceed to add a base even with an relatively insignificantly low Kb your solution would still be more basic then acidic. The answer should be b which is true that the base only ionizes slightly in aqueous solution. This is also truer to the definition of what Kb represents.
Answer:
a) The relationship at equivalence is that 1 mole of phosphoric acid will need three moles of sodium hydroxide.
b) 0.0035 mole
c) 0.166 M
Explanation:
Phosphoric acid is tripotic because it has 3 acidic hydrogen atom surrounding it.
The equation of the reaction is expressed as:

1 mole 3 mole
The relationship at equivalence is that 1 mole of phosphoric acid will need three moles of sodium hydroxide.
b) if 10.00 mL of a phosphoric acid solution required the addition of 17.50 mL of a 0.200 M NaOH(aq) to reach the endpoint; Then the molarity of the solution is calculated as follows

10 ml 17.50 ml
(x) M 0.200 M
Molarity = 
= 0.0035 mole
c) What was the molar concentration of phosphoric acid in the original stock solution?
By stoichiometry, converting moles of NaOH to H₃PO₄; we have
= 
= 0.00166 mole of H₃PO₄
Using the molarity equation to determine the molar concentration of phosphoric acid in the original stock solution; we have:
Molar Concentration = 
Molar Concentration = 
Molar Concentration = 0.166 M
∴ the molar concentration of phosphoric acid in the original stock solution = 0.166 M
Molarity can be defined as the number of moles of substance dissolved in 1 L of solution.
In the given question ,
number of LiOH moles - 1.495 mol
Dissolved volume - 750 mL
molarity is calculated for 1 L = 1000 mL
In 750 mL - 1.495 mol of LiOH is dissolved
Therefore in 1000 mL - 1.495 mol / 750 mL x 1000 = 1.99 mol
Answer:
At this partial pressure of oxygen, Mb would be almost completely saturated but Hb would not.
Explanation:
The oxygen saturation curves for Mb and Hb are quite different. The curve for Mb is hyperbolic while that for Hb is sigmoidal.
Mb reaches oxygen saturation before Hb.
Thus, at a partial pressure of 40 mmHg, Mb is almost completely saturated but Hb is not.