Buffer is a solution which resist the change in pH with addition of small amount of acid or base.
Hence when small amount of acid is added to buffer its pH will not change, as the buffer has the capacity to resist the change in pH on small addition of acid or base to it.
Buffer is mixture of weak acid/base and its conjugate base/acid.
Hence when small amount of acid is added to HA/A-. The H+ ions added reacts with the conjugate base A- in buffer forming the weak acid and thus keeping the pH same.
For the first Question,
d. It is a substance that cannot be chemically broken down any further.
For the second Question,
Please right the whole options completely so that I can answer
Answer:
molality of sodium ions is 1.473 m
Explanation:
Molarity is moles of solute per litre of solution
Molality is moles of solute per kg of solvent.
The volume of solution = 1 L
The mass of solution = volume X density = 1000mL X 1.43 = 1430 grams
The mass of solute = moles X molar mass of sodium phosphate = 0.65X164
mass of solute = 106.6 grams
the mass of solvent = 1430 - 106.6 = 1323.4 grams = 1.3234 Kg
the molality =
Thus molality of sodium phosphate is 0.491 m
Each sodium phosphate of molecule will give three sodium ions.
Thus molality of sodium ions = 3 X 0.491 = 1.473 m
You have to find how many moles of H2 has formed.
C+ H2O -> CO + H2
mole of carbon reacted = mass / molar mass = 34g/ 12g per mol = 2.83 mol
for every 1 mole of carbon will form 1 mole of H2
mole of hydrogen produced = 1* 2.83 = 2.83 mol
mass of hydrogen = mole * molar mass = 2.83 mol * (1*2) = 5.66g