Asmall amount of acid is added to a buffered solution. what will happen

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.

given:

mass of na = 115 g

excess cl2

to determine:

mass of nacl produced

explanation:

given reaction is-

2na(s) + cl2(g) → 2nacl(s)

since cl2 is in excess, na will be the limiting reagent

as per the reaction stoichiometry na: nacl = 1: 1

i.e. moles of na reacted = moles of nacl formed

now, # moles of na = mass of na/atomic mass

                                  = 115 g/23 g.mol-1 = 5 moles

therefore, moles of nacl = 5

molar mass of nacl = 58 g/mol

mass of nacl = 5 moles * 58 g.mol-1 = 290 g

ans: amount of nacl produced = 290 g