Honors Chem Semester Review (Ch 1-5)

Front

What is the chemical formula for oxygen difluoride?

Back

OF₂

Front

Convert 25 g of As₂Pe₃ to moles. (Peeyew is a fictional element found on the dwarf planet Pluto)

Back

0.0993 moles

Front

Calculate ΔH in kJ/mol for the reaction: N₂(g) + O₂(g) → 2 NO(g) when 0.35 mols of N₂ reacts, absorbing 63.21 kJ of heat.

Back

+ 180.6 kJ

Front

What is the empirical formula (simplest whole number ratio) for a compound with 82.2% N and 17.8% H?

Back

NH₃

Front

What is the net ionic equation for the reaction: CaCl₂ + 2 AgNO₃ → Ca(NO₃)₂ + 2 AgCl?

Back

Ag⁺ + Cl⁻ → AgCl

Front

Define empirical formula.

Back

The empirical formula is the simplest whole number ratio of elements in a compound.

Front

What is the difference between molecular formula and empirical formula?

Back

The molecular formula shows the actual number of atoms of each element in a molecule, while the empirical formula shows the simplest ratio of the elements.

Front

What is the significance of ΔH in a chemical reaction?

Back

ΔH represents the change in enthalpy, indicating whether a reaction is exothermic (releases heat) or endothermic (absorbs heat).

Front

How do you calculate moles from grams?

Back

Moles = mass (g) / molar mass (g/mol).

Front

What is a net ionic equation?

Back

A net ionic equation shows only the species that participate in a reaction, omitting spectator ions.