1. When does the dissociation of water affect the pH of an acidic solution?

a) never
b) only when the [H⁺ from acid dissociation is less than 1.0x10^-6 M
c) always, but the effect is only significant when the [H⁺] from acid dissociation alone is less than 1.0x10^-6 M
d) always, and the effect is always significant

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