Neco Model Questions Vol1 2023 Chemistry Question 2

Practice practical question 2 from the 2023 Neco Model Questions Vol1 Chemistry examination. This question covers Periodic Table .

Neco Model Questions Vol1 2023 Chemistry Practical
Topic: Periodic Table
Question 2 NECO_MODEL_QUESTIONS_VOL1 • 2023 • CHEMISTRY • practical

A flame‑test was performed on an unknown aqueous solution. The flame observed was bright yellow‑orange and a spectroscope showed a dominant emission line at a wavelength of 589 nm. Answer the following:

Question Parts

( a )
Identify the metal ion present in the unknown solution.
( b )
Calculate the energy of a single photon corresponding to the 589 nm emission (in joules) and the energy per mole of photons (in kJ mol⁻¹). Use h = 6.626 × 10⁻³⁴ J s and c = 3.00 × 10⁸ m s⁻¹; Avogadro's number = 6.022 × 10²³ mol⁻¹.
( c )
A second emission line at 400 nm is also known for the same element. Determine the difference in energy (kJ mol⁻¹) between the 400 nm photon and the 589 nm photon.
( d )
Briefly explain why the flame colour is produced in terms of electronic transitions of the metal atoms.

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About This Question

This is Neco Model Questions Vol1 2023 Chemistry Question 2. It is one of the practical questions from the 2023 Neco Model Questions Vol1 Chemistry examination.

The question covers Periodic Table .

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