Do acidic or basic salts affect litmus paper, pls answer asap

It depends on the salt

Look at the cation and anion that make up the salt. If they both came from a strong acid and a strong base, then the salt will be pretty much neutral. Take table salt, NaCl. You can make it for NaOH (strong base) and HCl (strong acid) so it’s neutral.

This probably answers what you were actually asking, but I’m going to tell the whole story.

Now sodium citrate is a salt that can be NaOH (strong base) and citric acid (weak acid). When dissolved in water some of the citrate reassociates with hydrogen to become citric acid again. By taking free hydrogen ions out of the water, it’s shifting the water basic. So…

Strong acid + strong base ==> neutral
Weak acid + strong base ==> basic (litmus turns blue)
Strong acid + weak base ==> acidic (litmus turn red)
Weak acid + weak base ==> depends on which one in stronger