Qui, quaff, quin, quinol, quirk, quirky, quo, quoin, quor, quy, quack, quackangle, quacked, quackery, quacking, quackish, quacks, quad, quadrate, quadrangle, quadrangles, quadrant, quadrantes,...
Quiz and equip are the only ones that come to mind but I hope it helps.. :D
QIIn Chinese culture, a physical life force[ODE][C][AHC][OED]Commonly written chi or kiChinese 氣, 'air'
From the official US Scrabble dictionary: aquae aquas burqa equal equid equip faqir fique maqui pique qadis qaids qanat qophs quack quads quaff quags quail quais quake quaky quale qualm quant quare...
quack, quaint, quarter, quick, quid, quip, quantify, quantum, quadratic, quartic, quintic, quicksilver, quicksand, que, quell,