Ib Chemistry Hl Topic 1

1. Determine the number of particles and the amount of substance (in moles).

Number of particles = Mass x Molar Mass x Avogadro's Number.

Particles = Moles x Avogadro's Number.

Convert between the amount of substance (inmoles) and the number of atoms, molecules, ions,electrons and formula units.
Moles = Mass / Molar Mass

Moles = Molar Mass x Mass / Volume.

2. Define the terms relative atomic mass (Ar) and relative molecular mass (Mr).

Dalton Mass: Another term used for relative atomic mass and relative molecular mass.

Molar Mass: The mass (in grams) per mole of a substance where C12 is exactly 12g. Molecular Mass: The mass per mole of a substance where C12 is exactly 12g.

Gram Mass: The mass of a substance in grams.

Atomic Mass: The mass of an atom in grams.

The correct answer provides the definition of Molar Mass and Molecular Mass specifically related to the standard of C12 being 12g.

Explanation

The correct answer provides the definition of Molar Mass and Molecular Mass specifically related to the standard of C12 being 12g.

3. Distinguish between the terms empirical formula and molecular formula.

Ionic formula: Represents the ratio of ions in an ionic compound.

Isomeric formula: Represents different compounds with the same molecular formula.

Empirical formula: The simplest ratio of the atoms in a chemical compound. Molecular formula: The actual ratio of the atoms in a chemical compound.

Structural formula: Shows the arrangement of atoms within a molecule.

The empirical formula gives the simplest ratio of atoms, the molecular formula provides the actual ratio of atoms, while structural formula shows the arrangement of atoms within a molecule. Ionic formula represents the ratio of ions in an ionic compound, and isomeric formula represents different compounds with the same molecular formula.

Explanation

The empirical formula gives the simplest ratio of atoms, the molecular formula provides the actual ratio of atoms, while structural formula shows the arrangement of atoms within a molecule. Ionic formula represents the ratio of ions in an ionic compound, and isomeric formula represents different compounds with the same molecular formula.

4. 1.2.6: Determine the molecular formula when given both the empirical formula and experimental data.

Percentage composition is not relevant when determining the molecular formula.

If a molecular formula is given, percentage composition can be calculated.

Experimental data is not necessary when determining the molecular formula.

The empirical formula alone is sufficient for determining the molecular formula.

In this question, it is important to understand that percentage composition plays a crucial role in determining the molecular formula when given both the empirical formula and experimental data. The incorrect answers provided focus on misconceptions related to this process.

Explanation

In this question, it is important to understand that percentage composition plays a crucial role in determining the molecular formula when given both the empirical formula and experimental data. The incorrect answers provided focus on misconceptions related to this process.

5. 1.3.1: Deduce chemical equations when all reactants and products are given.

Chemical equations represent a random combination of elements without any rules.

The balance of chemical equations is not important in chemistry.

Students should prioritize memorization of equations over understanding their components.

Students should be aware of the differencebetween coefficients and subscripts.

Understanding the concepts of coefficients and subscripts in chemical equations is crucial for students to accurately deduce and balance equations in chemistry.

Explanation

Understanding the concepts of coefficients and subscripts in chemical equations is crucial for students to accurately deduce and balance equations in chemistry.

6. Identify the mole ratio of any two species in a chemical equation.

Confusing

Straightforward.

Complex

Challenging

The mole ratio of any two species in a chemical equation can usually be identified straightforwardly by looking at the coefficients in the balanced equation. It does not involve complex or confusing calculations.

Explanation

The mole ratio of any two species in a chemical equation can usually be identified straightforwardly by looking at the coefficients in the balanced equation. It does not involve complex or confusing calculations.

7. Apply the state symbols (s), (l), (g) and (aq) where applicable in chemical equations.

C. To determine the reaction rate in a chemical equation.

Apply in chemical equations.

A. To calculate the molar mass of each component in a chemical equation.

B. To balance the charges in a chemical equation.

In chemical equations, using state symbols (s), (l), (g), and (aq) is essential to denote whether a substance is in solid, liquid, gas, or aqueous form respectively.

Explanation

In chemical equations, using state symbols (s), (l), (g), and (aq) is essential to denote whether a substance is in solid, liquid, gas, or aqueous form respectively.

8. 1.4.1: Calculate theoretical yields from chemical equations.

Theoretical Yield = Experimental Yield - Percentage Yield.

Theoretical Yield = Experimental Yield + Percentage Yield.

Percentage Yield = (Theoretical Yield / Experimental Yield) * 100.

Percentage Yield = (Experimental Yield / Theoretical Yield) * 100

9. Determine the limiting reactant and the reactant in excess when quantities of reacting substances are given.

Excess reagent: The reagent that is fully consumed in a reaction

Catalyst: A substance that increases the rate of a reaction without being consumed in the process

Product: The end result of a chemical reaction

Limiting reagent: The reagent that limits or determines the amount of product that can be formed in areaction. The reaction occurs only until the limiting reagent is used up.