How many moles of hydrogen will react with 40g oxygen

2.5 moles

2H2 + O2 = 2H2O

This implies that 2 moles of oxygen is needed to react with one mole of oxygen to form 2 moles of water

It also implies that

2 moles of hydrogen requires 32 grams of oxygen

? moles of hydrogen would require 40 g of oxygen

2 x 40/32 = 2.5 moles

here is table 2-2:

country

percent of eligible voters that voted

rank

united states

44.9%

138

canada

60.1%

107

costa rica

84.6%

14

hungary

66.9%

82

japan

57.0%

118

egypt

27.7%

159

south africa

85.5%

10

ans is no, the data set cannot be plotted as a single circle graph