The pH increases because the HCl is becoming less acidic. A pH of 7 is neutral. A pH falls below 7, acidity increases. As pH rises above 7, basicity increases. Diluting HCl means that the HCl becomes...
Well, let's see . . . I'm pretty sure there's more mass in Lake Michigan than there is in a glass of water.
If you keep the amount of "stuff" (the 0.3 liters of water in the glass) the same and...