CHM 130 Fundamental Chemistry
Questions and answers, well
explained
What is the main difference between an element and a compound?
☑️ An element consists of one type of atom, while a compound contains two or more different
atoms chemically bonded.
How does atomic number differ from mass number?
☑️ Atomic number is the number of protons, while mass number is the total of protons and
neutrons.
What is the significance of isotopes in chemistry?
☑️ Isotopes are atoms of the same element with different numbers of neutrons, affecting atomic
mass but not chemical identity.
Why do atoms form chemical bonds?
☑️ Atoms bond to achieve a more stable electron configuration, often resembling noble gases.
What type of bond involves the sharing of electrons?
☑️ A covalent bond.
What type of bond is formed through the transfer of electrons?
☑️ An ionic bond.
How does electronegativity influence bond type?
☑️ A large difference leads to ionic bonds, while a small difference leads to covalent bonds.
What is a mole in chemistry?
☑️ A mole is the amount of substance containing 6.022 × 10²³ particles.
Why is Avogadro’s number important?
☑️ It allows conversion between particles and moles.
What does molar mass represent?
☑️ The mass of one mole of a substance.
How do you determine empirical formula from experimental data?
☑️ By finding the simplest whole-number ratio of elements.
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, What is the law of conservation of mass?
☑️ Mass is neither created nor destroyed in a chemical reaction.
What does balancing a chemical equation ensure?
☑️ Equal numbers of each type of atom on both sides.
What is the role of a limiting reagent?
☑️ It determines the maximum amount of product formed.
What happens when a reactant is in excess?
☑️ It remains unreacted after the limiting reagent is consumed.
What is percent yield?
☑️ The ratio of actual yield to theoretical yield multiplied by 100.
How does temperature affect reaction rate?
☑️ Increasing temperature generally increases reaction rate.
What is activation energy?
☑️ The minimum energy required for a reaction to occur.
What is a catalyst?
☑️ A substance that speeds up a reaction without being consumed.
What distinguishes exothermic from endothermic reactions?
☑️ Exothermic releases heat, endothermic absorbs heat.
What is enthalpy?
☑️ The heat content of a system at constant pressure.
What does a negative ΔH indicate?
☑️ The reaction is exothermic.
What is the pH scale used for?
☑️ Measuring the acidity or basicity of a solution.
What pH value indicates neutrality?
☑️ pH 7.
What defines an acid according to Arrhenius?
☑️ A substance that produces H⁺ ions in solution.
What defines a base according to Arrhenius?
☑️ A substance that produces OH⁻ ions in solution.
2
Questions and answers, well
explained
What is the main difference between an element and a compound?
☑️ An element consists of one type of atom, while a compound contains two or more different
atoms chemically bonded.
How does atomic number differ from mass number?
☑️ Atomic number is the number of protons, while mass number is the total of protons and
neutrons.
What is the significance of isotopes in chemistry?
☑️ Isotopes are atoms of the same element with different numbers of neutrons, affecting atomic
mass but not chemical identity.
Why do atoms form chemical bonds?
☑️ Atoms bond to achieve a more stable electron configuration, often resembling noble gases.
What type of bond involves the sharing of electrons?
☑️ A covalent bond.
What type of bond is formed through the transfer of electrons?
☑️ An ionic bond.
How does electronegativity influence bond type?
☑️ A large difference leads to ionic bonds, while a small difference leads to covalent bonds.
What is a mole in chemistry?
☑️ A mole is the amount of substance containing 6.022 × 10²³ particles.
Why is Avogadro’s number important?
☑️ It allows conversion between particles and moles.
What does molar mass represent?
☑️ The mass of one mole of a substance.
How do you determine empirical formula from experimental data?
☑️ By finding the simplest whole-number ratio of elements.
1
, What is the law of conservation of mass?
☑️ Mass is neither created nor destroyed in a chemical reaction.
What does balancing a chemical equation ensure?
☑️ Equal numbers of each type of atom on both sides.
What is the role of a limiting reagent?
☑️ It determines the maximum amount of product formed.
What happens when a reactant is in excess?
☑️ It remains unreacted after the limiting reagent is consumed.
What is percent yield?
☑️ The ratio of actual yield to theoretical yield multiplied by 100.
How does temperature affect reaction rate?
☑️ Increasing temperature generally increases reaction rate.
What is activation energy?
☑️ The minimum energy required for a reaction to occur.
What is a catalyst?
☑️ A substance that speeds up a reaction without being consumed.
What distinguishes exothermic from endothermic reactions?
☑️ Exothermic releases heat, endothermic absorbs heat.
What is enthalpy?
☑️ The heat content of a system at constant pressure.
What does a negative ΔH indicate?
☑️ The reaction is exothermic.
What is the pH scale used for?
☑️ Measuring the acidity or basicity of a solution.
What pH value indicates neutrality?
☑️ pH 7.
What defines an acid according to Arrhenius?
☑️ A substance that produces H⁺ ions in solution.
What defines a base according to Arrhenius?
☑️ A substance that produces OH⁻ ions in solution.
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