Question

if 10^20 molecules are removed from 50 mg of N2O, the no of moles of N2O left approximately

Answer 1

Answer:

Heya buddy............ ❤

Molar mass of N2O = 44

Given mass = 50 mg = 0.05 g

Numbers of moles = 0.05/ 44 = 1.136× 10^-3

Hence,

Number of moles = number of molecules / Avogadro's number

=> Number of molecules

= Avogadro's number *Number of moles

= 6.02 × 10^23 * (1.136 × 10^-3)

= 6.84 ×10^20 molecules in 1.136 × 10^-3 moles

Given, 10^20 molecules are removed,

Therefore, No of molecules left = ( 6.84 ×10^20) - (10^20)

= 5.84 ×10^20

Number of moles =

number of molecules /Avogadro's number

= (5.84 × 10^20)/ (6.02× 10^23)

= 9.7 × 10^-4

Hope it’s helpful...... ☆(❁‿❁)☆

Answer 2

Answer:...here is required answer

molecular mass of N₂O = 44

weight of N₂O = 200mg = 0.2g

moles of N₂O present = 0.2/44 = 4.55×10^(-3)

Let moles of N₂O removed = y

moles of N₂O remained = 2.89×10^(-3)

Thus 4.55×10^(-3) - y = 2.89×10^(-3)

⇒ -y = 2.89×10^(-3) - 4.55×10^(-3)  

⇒ y = 4.55×10^(-3) - 2.89×10^(-3)

⇒ y = 1.66×10^(-3) moles

No. of molecules in 1 mole = 6.022×10^(23)

No. of molecules in y moles = y×6.022×10^(23) = 1.66×10^(-3)×6.022×10^(23)                                                =9.97×10^(20)  

Thus  x = 9.97×10^(20) molecules

Explanation: