Foundations in chemistry

What do isotopes of an element differ in?

Isotopes of an element differ in the number of neutrons.

What is the mass number of an atom?

The mass number refers to the number of protons plus the number of neutrons.

What is the charge of a proton?

A proton has a positive charge.

What type of charge does a neutron have?

A neutron has a neutral charge.

Which isotope of hydrogen has one proton and one neutron?

Deuterium is the isotope of hydrogen that has one proton and one neutron.

What is an ion?

An ion is a charged atom with a different number of electrons than protons.

How are positive ions, or cations, formed?

Positive ions, cations, are formed when atoms lose electrons.

What is the standard isotope for atomic masses?

The standard isotope for atomic masses is carbon-12.

What does the relative atomic mass represent?

The relative atomic mass represents the weighted mean mass of an atom compared to 1/12 the mass of a carbon-12 atom.

What is the purpose of a mass spectrometer?

A mass spectrometer is used to determine the percentage abundance of isotopes in a sample.

What do covalent compounds consist of?

Covalent compounds consist of ions or small molecules made of non-metal atoms.

What type of formulation represents the simplest whole-number ratio of atoms?

The empirical formula represents the simplest whole-number ratio of atoms in a compound.

How is the percentage composition of an element in a compound calculated?

Percentage composition = ((relative atomic mass of element x number of atoms of element) / relative atomic mass of compound) x 100.

What happens when hydrated copper(II) sulfate is heated?

When heated, hydrated copper(II) sulfate loses water and becomes anhydrous copper(II) sulfate.

What is the definition of a standard solution?

A standard solution is one with a known concentration, made by dissolving an exact mass of solute in a specific volume of solvent.

What is the formula for calculating molarity?

Molarity (mol/dm³) = amount of solute (mol) / volume of solution (dm³).

What does the Avogadro constant represent?

Avogadro constant represents the number of particles in one mole, which is approximately 6.02 x 10²³ particles.

What does a strong acid do in solution?

A strong acid completely dissociates to release hydrogen ions (H⁺) in solution.

What kind of bonds do ionic compounds have?

Ionic compounds have strong electrostatic attractions between positive and negative ions.

How can you determine the limiting reagent in a reaction?

The limiting reagent is the reactant that is completely consumed first, stopping the reaction.

How is atom economy defined?

Atom economy measures the efficiency of a reaction by calculating the proportion of reactants that become useful products.

In terms of oxidation-reduction, what does oxidation refer to?

Oxidation refers to the loss of electrons or an increase in oxidation number.

What is a titration?

A titration is a technique used to determine the concentration of a solute in a solution by reacting it with a solution of known concentration.

What does the ideal gas equation account for?

The ideal gas equation accounts for the relationships between pressure, volume, temperature, and the number of moles of gas (PV = nRT).

What is a cohesive property of water?

Cohesion in water refers to the strong attraction between water molecules, leading to high surface tension.

What type of molecular shape does methane (CH₄) have?

Methane has a tetrahedral molecular shape.

What is the significance of hydrogen bonding in water?

Hydrogen bonding gives water unique properties such as high melting and boiling points and its lower density in solid form compared to liquid.

What type of bond forms when two atoms share electrons equally?

A non-polar covalent bond forms when two atoms share electrons equally.

What causes the polarity of water molecules?

The polarity of water molecules is caused by the difference in electronegativity between hydrogen and oxygen, leading to partial charges.

What happens during a neutralization reaction?

A neutralization reaction occurs when an acid reacts with a base to form a salt and water.

How does temperature affect gas volume?

At constant pressure, the volume of a gas increases with an increase in temperature, according to Charles's Law.

What does a displayed formula show?

A displayed formula shows the relative positioning of atoms and the bonds between them in a molecule.

What are non-polar molecules typically soluble in?

Non-polar molecules are typically soluble in non-polar solvents.

What kind of structure do simple molecular substances have?

Simple molecular substances form a simple molecular lattice held together by weak intermolecular forces.

Why are simple molecular substances poor conductors of electricity?

Simple molecular substances lack mobile charged particles which are necessary to conduct electricity.

How can the reactivity of metals be determined?

The reactivity of metals can be determined by their ability to lose electrons and form cations.

What is a binary compound?

A binary compound consists of two different elements.

Define a molecule.

A molecule is a group of atoms bonded together, which can be the same or different elements.

What is a polyatomic ion?

A polyatomic ion is an ion composed of two or more atoms covalently bonded, that carries a charge.

What is meant by "spectator ions" in a chemical reaction?

Spectator ions are ions that do not participate in the actual reaction and remain unchanged on both sides of the equation.

What is the significance of using an indicator in titrations?

Indicators are used in titrations to signal the end point of the reaction, often by changing color.

What kind of interaction do hydrogen bonds represent?

Hydrogen bonds are strong intermolecular forces that occur between molecules that contain hydrogen bonded to electronegative atoms.

How does increasing temperature affect the kinetic energy of gas molecules?

Increasing temperature raises the kinetic energy of gas molecules, resulting in greater movement and press