Calculate the mass of ammonia that contains a trillion hydrogen atoms.

              9.4 × 10⁻¹² g of NH₃

Solution:

Step 1: Calculate Number of NH₃ Molecules containing 1 Trillion Hydrogen Atoms:

As,

                  3 Hydrogen Atoms are present in  =  1 Molecule of NH₃

So,

    1 × 10¹² Hydrogen Atoms will be present in  =  X Molecules of NH₃

Solving for X,

                      X  =  (1 × 10¹² × 1) ÷ 3

                      X =  3.33 × 10¹¹ Molecules of NH₃

Step 2: Calculate Moles of NH₃:

As,

                          Moles  =  Number of Molecules ÷ 6.022 × 10²³

Putting value,

                          Moles  =  3.33 × 10¹¹ Molecules ÷ 6.022 × 10²³

                          Moles  = 5.53 × 10⁻¹³ mol

Step 3: Calculate Mass of NH₃:

As,

                          Moles  =  Mass ÷ M.Mass

Solving for Mass,

                          Mass  =  Moles ×  M.Mass

Putting values,

                          Mass  =  5.53 × 10⁻¹³ mol × 17 g.mol⁻¹

                          Mass =  9.4 × 10⁻¹² g of NH₃

the answer for sodium is 0.186

the answer for rubidium is 0.251

a pan containing water is placed in a positio n where it is exposed to a 10 mile per hour wind. the pan contains a uniform depth of 1.27 cm of water, is quite wide, and has a length of 2.44 m in the wind direction. the water in the pan is at a constant temperature of 15.5 °c.