Question

calculate the mass of
1) 0.1M KNO3
2) 1*10^23 molecule of methane
3)122cm3 of hydrogen at stp​

Answer 1

Answer:

(1) molecular weight of KNO3= 39+14+3×16 g

= 39+14+48 g

= 101 g

1 mole = 101 g

0.1 mole = 101×0.1 g

= 10.1 g

(2) 6.023×10^23 molecule methane mass = 16 g

1×10^23 molecule methane mass = 16×10^23/6.023×10^23=2.656 g

(3) mass of 22400cm^3 H2= 2 g

mass of 112 cm^3 H2 = 2/22400×112=0.01 g