Question

When 60cm^3 each of H2 and o2 react together the theoretical decrease in the volume of the reacting gases will be

Answer 1

TP or s.t.p. is a largely defunct abbreviation for 'standard temperature and pressure', 0oC/273K temperature and a pressure of 1 atm/101.3 kPa (101325 Pa). (In bygone times 760 mm of Hg of a 'mercury' barometer/manometer)

NTP or RTP is a frequently used abbreviation for 'normal laboratory temperature and pressure', 25oC/298K temperature and  pressure of 1 atm/101.3 kPa pressure (101325 Pa).