The original concentration of the acid solution is 6.175 
10^-4 mol / L.
<u>Explanation:</u>
Concentration is the ratio of solute in a solution to either solvent or total solution. It is expressed in terms of mass per unit volume
HBr + NaOH -----> NaBr + H2O
There is a 1:1 equivalence with acid and base.
Moles of NaOH = 72.90 10^-3 0.25
= 0.0182 mol.
[ HBr ] = moles of base / volume of a solution
= 0.0182 / 29.47
= 6.175 10^-4 mol / L.
The letter only has reflection symmetry, if you rotated it it would look the same.
C! The clownfish hide in the sea anemones for protection
Because that is the outer ring.
2 moles of sodium hydroxide will be needed.
<h3><u>Explanation</u>:</h3>
Sodium hydroxide is a compound which is a base and nitric acid is the acid. The formula of the nitric acid is HNO3 and that of sodium hydroxide is NaOH.
The reaction between them are
NaOH +HNO3 =NaNO3 +H2O.
So here we can see that 1 mole of sodium hydroxide reacts with 1 mole of nitric acid to produce 1 mole of sodium nitrate and 1 mole of water.
So for 2 moles of nitric acid, 2 moles of sodium hydroxide will be required.
