10 Most VSAQ’s of Stoichiometry Chapter in Inter 1st Year Chemistry (TS/AP)

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In O₂, the oxidation number of oxygen is 0 because it exists in its elemental form, and elemental oxygen always has an oxidation state of 0.
In OF₂, the oxidation number of oxygen is -2. This is because fluorine (F) is more electronegative than oxygen, and in compounds, fluorine has an oxidation state of -1. Since there are two fluorine atoms in OF₂, they contribute a total of -2 to the molecule. To maintain overall charge neutrality, the oxidation state of oxygen is +2.

There are 3 moles of glucose present in 540 grams of glucose.

There are 2 moles of CaCO₃ (calcium carbonate) present in 200 grams of CaCO₃.

The weight of 0.1 mole of sodium carbonate (Na₂CO₃) is 10.6 grams.

The molecular formula of the compound is C₃H₆O₃.

Calculate the number of moles of NaOH: Moles = Mass (g) / Molar mass (g/mol)The molar mass of NaOH (sodium hydroxide) is approximately 40 g/mol.Moles of NaOH = 4 g / 40 g/mol = 0.1 moles
Calculate the volume of the solution in liters: Volume (L) = 250 ml / 1000 ml/L = 0.25 L
Calculate the molarity (M) using the formula: Molarity (M) = Moles / Volume (L)Molarity (M) = 0.1 moles / 0.25 L = 0.4 M

So, the molarity of the NaOH solution is 0.4 M.

Definition: These reactions involve a substance undergoing simultaneous oxidation and reduction, forming two different compounds with varying oxidation states.
Example: Hydrogen peroxide (H₂O₂) decomposing into water (H₂O) and oxygen (O₂) is a disproportionation reaction.