To determine which reaction is NOT a redox reaction, we must understand what constitutes a redox reaction. In a redox (reduction-oxidation) reaction, there is a transfer of electrons between species, leading to changes in their oxidation states. We'll analyze each option to check the oxidation state changes:
Zn + CuSO4 → ZnSO4 + Cu
Zinc (Zn) is oxidized from 0 to +2 and copper (Cu) is reduced from +2 to 0. This is a redox reaction.
2KClO3 + I2 → 2KIO3 + Cl2
Chlorine changes from +5 in KClO3 to 0 in Cl2 (reduction), and iodine changes from 0 to +5 in KIO3 (oxidation). This is a redox reaction.
H2 + Cl2 → 2HCl
Hydrogen changes from 0 to +1, and chlorine changes from 0 to -1. This is a redox reaction.
BaCl2 + Na2SO4 → BaSO4 + 2NaCl
No change in oxidation states for barium, sodium, or chloride as both sides have the same oxidation numbers. This is a double displacement reaction, not a redox reaction.
The reaction: BaCl2 + Na2SO4 → BaSO4 + 2NaCl is NOT a redox reaction.
A bob of heavy mass \(m\) is suspended by a light string of length \(l\). The bob is given a horizontal velocity \(v_0\) as shown in figure. If the string gets slack at some point P making an angle \( \theta \) from the horizontal, the ratio of the speed \(v\) of the bob at point P to its initial speed \(v_0\) is :