Question

2 mole of sulphate ions $\left({SO}_4^{2-}\right)$ would have:

• A. same number of electrons as in 2 mole of nitrate ions ${NO}_3^{-}$
• B. same number of neutrons as in 2 mole of phosphate ions $\left({PO}_4^{3-}\right)$
• C. same number of electrons as in 290 of phosphate ions $\left({PO}_4^{3-}\right)$
• D. None of these

Answer 1

The correct option is B same number of neutrons as in 2 mole of phosphate ions $\left({PO}_4^{3-}\right)$

In 2 moles of sulphate ion,

• No. of moles of electrons :
  

= 2 x [no. of e⁻ in S + (4 x no. of e⁻ in O) + 2 ]

= 2 x [ 16 + (4 x 8) + 2]

= 2 x [50] = 100

• no. of moles of neutrons :

= 2 x [no. of neutrons in S + (4 x no. of neutrons in O)]

= 2 x [ 16 + (4 x 8) ]

= 96.

A) No. of electrons in 2 mol of NO₃⁻ :

= 2 x [ no. of e⁻ in N + (3 x no. of e⁻ in O) + 1]

= 2 x [ 7 + (3 x 8) + 1]

= 2 x [32] = 64

Option A is incorrect.

B) No. of neutrons in 2 mol of PO₄³⁻ :

= 2 x [ no. of neutrons in P + (4 x no. of neutrons in O)]

= 2 x { 16 + (4 x 8)]

= 2 x [48] = 96

Thus, option B is correct.