Answer:
1. & 2.
Explanation:
mass of Na = 23 u
mass of S = 32 u
mass of oxygen = 16 u
Thus, Na2S2O3
= 23(2) + 32(2) + 16(3)
= 46 + 64 + 48
= 110 + 48
= 158 u.
Dissolving a salt of a weak acid or base in water
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