That should produce an error because \' ' is not a valid escape sequence.
If you don't like the default spacing then don't use tabs. Do something like this: printf("%-20s", "Hello World"); where the text string will be left-justified in a field 20 characters wide, right-side padded with spaces.
C doesn't specify tab stops, only tab characters. It's up to the program consuming those characters to interpret the character with a certain tab stop length, just like it's up to the same program to accurately print the 'Q' character. Translation: change the properties of whatever program is displaying those tabs to use a five character tab stop explicitly. Most likely this will be your shell, for command line programs that send output to stdout.