Formulas & Percent Composition
Define "mass percent composition".
What is the mass percent of each element in a compound = (mass of element / total mass) × 100%.
What products are always formed when a CHO compound is combusted?
What is CO₂ and H₂O
Name NaCl.
What is Sodium chloride
Which molecule violates the octet rule: BF₃, CH₄, or H₂O?
What is BF₃
As you move left → right across a period, what happens to atomic size?
What is decreases
A compound is 40.0% C, 6.7% H, and 53.3% O by mass. What is its empirical formula?
What is CH2O?
A compound contains C, H, and O. 2.20 g of it produces 3.21 g CO₂ and 1.31 g H₂O. What’s the empirical formula?
CH2O
Name P₄O₁₀
Tetraphosphorus decoxide
Determine the formal charge on each atom in CO
What is C: –1, O: +1
Which atom has the higher ionization energy, Na or Mg?
The empirical formula of a compound is CH₂. Its molar mass is 56 g/mol. What’s its molecular formula?
What is C4H8?
Why must you find moles of C, H, and O when doing combustion analysis?
What is to determine their simplest ratio (empirical formula)
Give the formula for magnesium nitrate
What is Mg(NO₃)₂
Draw the Lewis structure for ClF3 and determine the electron and molecular geometry
What is trigonal bipyramidal electron geometry and T-shaped molecular geometry
Which element is more electronegative: O or S?
O
If 24.0 g of Mg combines with 16.0 g of O, what is the empirical formula?
What is MgO?
A 2.50 g sample of an unknown compound containing carbon, hydrogen, and oxygen is combusted, producing 5.50 g of CO₂ and 2.25 g of H₂O. Determine the empirical formula of the compound.
What is C₈H₁₆O₃
Name FeCl₃
What is Iron(III) chloride
Predict the molecular geometry and polarity of SF₄
What is Seesaw; polar
Rank F, Cl, and Br in order of increasing electronegativity.
What is Br < Cl < F
A compound has a molar mass of 150 g/mol and is 48.0% C, 8.0% H, and 44.0% O.
What is C₆H₁₂O₄
A 1.25 g sample of an unknown compound containing C, H, and O produces 2.75 g CO₂ and 1.12 g H₂O upon complete combustion. The compound’s molar mass is 60.0 ± 2 g/mol. Determine the molecular formula of the compound.
What is C₃H₆O
Name Pb(NO₂)₂
What is Lead (II) nitrite
Draw and name the shape of CH₂Cl₂. Is it polar or nonpolar?
What is Tetrahedral; polar
Rank the following elements from lowest to highest electron affinity:
O, F, and Cl.
What is O < F < Cl