UV-Vis spectroscopy is not typically used for direct pH measurement.

Gas chromatography is not a type of titration; it is a separation technique used for analyzing volatile compounds.

Determining molecular weight is not a common use of IR spectroscopy; it is primarily used for identifying functional groups and analyzing molecular vibrations.

Analyzing gas samples is not a common use of UV-Vis spectroscopy, as it is typically used for liquid samples.

Amino acids are not components of nucleotides; nucleotides consist of a phosphate group, a sugar, and a nitrogenous base.

Sublimation is not a method used for extracting metals; it is a phase transition from solid to gas.

Hydrometallurgy is a method of extracting metals from ores using aqueous solutions, while the other options are traditional extraction methods.

Structural isomerism refers to isomers with different connectivity, not stereoisomerism.

Thermal titration is not a recognized type of titration; the common types include acid-base, redox, and complexometric titrations.

While IR spectroscopy can provide qualitative information about organic compounds, it is not typically used for measuring concentrations of solutions.

Enthalpy is measured in energy units such as Joules, Kilojoules, or Calories, but not in pressure units like Atmospheres.

Hydrogen is not used in the direct synthesis of nitric acid; instead, it is primarily used in the production of ammonia and hydrogenation processes.

The general formula for alkanes is C_nH_{2n+2}, where n is the number of carbon atoms.

The correct IUPAC name for 2-methylpropene is 2-methylprop-1-ene, indicating the position of the double bond.

The compound has a triple bond at the first carbon and a methyl group at the third carbon, making it 3-methyl-1-pentyne.

The longest chain has 4 carbons with a methyl group on the second carbon, making it 2-methylbutane.

The correct IUPAC name for CH3-CH2-CH2-CH(OH)-CH3 is 3-Pentanol, as the hydroxyl group is on the third carbon of the longest chain.

The compound has four carbons and an aldehyde functional group, making it butanal.

The compound CH3-CH2-COOH is propanoic acid, as it has a three-carbon chain with a carboxylic acid functional group.

The longest carbon chain has 5 carbons with a triple bond starting at the second carbon, hence the name 2-pentyne.

The longest chain with the double bond is 5 carbons long, and the double bond starts at the second carbon, making it 2-pentene.

The longest chain with the triple bond is 5 carbons long, and the triple bond starts at the second carbon, making it 2-pentyne.

The longest chain has 4 carbons, and the methyl group is on the second carbon, making it 2-Methylbutanoic acid.

The longest chain has five carbons with a ketone group on the third carbon, making it 3-Pentanone.

The compound has a carboxylic acid functional group and a methyl group on the third carbon of a four-carbon chain, making it 3-Methylbutanoic acid.

The addition of HBr to propene occurs via an electrophilic addition mechanism.

The hydration of an alkene occurs via an electrophilic addition mechanism, where the alkene acts as a nucleophile.

The hydrogenation of an alkene involves the addition of hydrogen across the double bond, which is an electrophilic addition mechanism.

The reaction of 1-bromopropane with sodium hydroxide proceeds via an S2 mechanism, which is a bimolecular nucleophilic substitution.

The compound is an amine with two carbon atoms, and the correct IUPAC name is ethanamine.