IB Chemistry IA Examples

VSEPR Theory predicts molecular geometries based on electron pair repulsion. However, it typically doesn't account for atom or functional group identity. 

The study explores whether there's a relationship between halogen identity and tetrahedral bond angles.  Observing iodine's larger size and electron shells in CH2I2, the hypothesis suggests iodine-carbon-iodine bond angles to be wider. 

Compound molar mass comparisons suggest the significant impact of functional groups like carbonyl or hydroxyl on boiling points. The study explores how increasing hydrocarbon chain length could affect this impact. Additionally, the influence of functional group position in a chain on intermolecular forces is examined. 

Research questions focus on the convergence of melting and boiling points between alkanes and aldehydes, ketones, and alcohols with increasing carbon numbers and the effect of functional group positioning.

The investigation focuses on bond length, strength, and polarity in alcohols. Atom position and orbital overlap impact bond energy. Surrounding atoms can modify bond reactivity by altering electron cloud density. 

This study examines changes in electron cloud density in C-O bonds in alcohols due to surrounding atoms, particularly methyl groups and CH₂. The positive inductive effect of methyl groups is explored, affecting partial charges. 

This investigation aims to study the impact of temperature on the denaturation rate of egg white proteins and determine the Activation Energy involved.

The study connects temperature with molecular velocity, collision frequency, and reaction rates, revealing how collisions with energy surpassing Activation Energy trigger reactions. Protein structures (primary, secondary, tertiary, quaternary) and their impact on denaturation are also explored.

Declining oceanic pH due to increased CO₂ dissolution, termed ocean acidification, endangers coral reef formation by reducing the rate of calcium carbonate (CaCO₃) production. Investigating the reaction rate between CaCO₃ and HCl, this study aims to determine the reaction's order. 

The hypothesis suggests a first-order relationship between acid concentration and reaction rate, which could reflect the accelerated destruction of coral reefs as ocean acidity rises.

Olive oil comprises triglycerides, containing fatty acids, glycerol, and other components. Conversion of triglycerides to soap is saponification, involving hydrolysis by potassium or sodium hydroxide to form respective oleates. 

This study focuses on synthesizing potassium oleate and sodium oleate soaps, aiming to compare their characteristics and properties, and assessing the impact of changing from potassium to sodium salt on these attributes. 

This investigation explores how varying storage temperatures affect the concentration of hydroperoxides in sunflower oil due to oxidative rancidity. 

The prediction suggests that as temperature increases, the oxidation rate will also increase linearly. Hydroperoxide concentration, an indicator of oxidation, is assessed by measuring the absorbance of red light when the oil reacts with potassium dichromate (IV). The absorbance signifies hydroperoxide concentration, and colorimetry helps evaluate this relationship.

The study seeks to determine how the number of carbon atoms in the alcohol chain influences the enthalpy change of combustion. The hypothesis suggests that as the carbon atom count increases, the enthalpy of combustion will also increase due to stronger carbon-oxygen (C=O) bond formation. 

Additionally, the study aims to explore differences between experimentally determined enthalpy changes and those calculated using bond energies. 

This investigation aims to identify a suitable lipid for soap production by evaluating various factors. To achieve this, the saponification value is used which reflects the number of milligrams of potassium hydroxide needed to neutralize fatty acids obtained from the complete hydrolysis of 1g of fat. 

It provides insights into fatty acid characteristics and molecular weight. Olive oil is advantageous due to its higher resistance to oxidation and affordable price, making it a promising choice for soap manufacturing.

The investigation focuses on the visual appeal of food, recognizing color's significance in our food choices. A spectrophotometer was used to analyze the changing color during cooking to investigate the impact of heat on chlorophyll degradation in broccoli. 

The experiment demonstrates that cooking time influences chlorophyll's thermal stability, leading to color changes from green to brownish green and yellowish. It is anticipated that longer cooking times result in increased absorbance wavelength and color shifts from green to olive green.

The investigation explores the impact of pH changes (ranging from 2 to 10) on the molecular weight of polyvinyl alcohol by assessing its viscosity. Polyvinyl alcohol, a colorless and tasteless powder, serves as a binding and coating agent in the food industry, contributing to moisture protection. 

The hypothesis suggests that the molecular weight of polyvinyl alcohol may decrease at extreme pH levels due to potential decomposition, with stability anticipated around pH 6-7. 

The study focuses on sodium polyacrylate, a superabsorbent polymer utilized in industrial and consumer products. The investigation explores sodium polyacrylate's effectiveness in absorbing common metal ions, aiming to identify its potential for decontaminating water sources following industrial metal leaks. 

By exploring its ion absorption properties, this research aims to contribute to the development of strategies for water supply purification in the face of metal contamination incidents.

The investigation examines whether the number of electrons within the d-block orbital of d-block 2⁺ metal ions influences their capability to reduce the activation energy of the peroxidisulphate thiosulphate iodine clock reaction.

It's hypothesized that the catalytic behavior of transition metals hinges on their capacity to participate as electron donors and acceptors in redox reactions. This suggests that a greater number of electrons in the d-subshell could lead to decreased catalytic ability due to increased electron repulsion, consequently raising the activation energy of the alternative reaction pathway.

This investigation explores how the covalent character of monovalent ionic salts influences the percentage difference between Born-Haber lattice enthalpies and Kapustinskii theoretical lattice enthalpies. 

The hypothesis suggests that as the electronegativity difference between bonded atoms diminishes, the percentage difference between the two lattice enthalpies will increase. Additionally, as the difference in ionic radii between cations and anions increases, the polarization effect strengthens. 

The concept of an ideal solution encompasses two components with balanced intermolecular attractions. Mixing does not cause volume or enthalpy changes, suggesting that component A's tendency to evaporate from a solution of A and B is akin to its behavior in pure liquid A. 

The investigation's goal is to analyze how the intermolecular forces between component molecules influence the mixture's boiling point under standard atmospheric pressure and temperature conditions.

Red wine's potential benefits for heart disease and cancer prevention are linked to its antioxidant content, particularly condensed tannins. Recent studies indicate tannins can inhibit superoxide radicals. 

This investigation aims to confirm this by evaluating the antioxidative capacity of red wine samples with varying tannin concentrations using the blue bottle experiment, expecting a positive linear correlation between tannin concentration and antioxidative ability.

Luminol, an organic compound, exhibits chemiluminescence through oxidation, resulting in light emission. The research question explores how altering luminol concentration influences the change in light intensity from the oxidation reaction. 

Light intensity is measured in lux as it's produced during the reaction. The hypothesis suggests that increased luminol concentration leads to greater light intensity during oxidation. It is assumed all energy produced is emitted as light, not heat loss. 

H⁺ ions and the enzyme invertase act as catalysts for sucrose hydrolysis, significant in sugar production. This study investigates the impact of changing the catalyst from hydrochloric acid to invertase on the reaction rate, measured by angle of rotation. 

Based on HCl and invertase catalysis mechanisms, the hypothesis suggests that hydrolysis rate will be greater with HCl as the catalyst than with invertase.