Atomic Structure & Periodic Trends
An atom has 26 protons, 30 neutrons, and 23 electrons. Identify the element, isotope notation, and charge.
⁵⁶₂₆Fe³⁺
Balance:
C₃H₈ + O₂ → CO₂ + H₂O
1 : 5 : 3 : 4
Lewis structure NO₃⁻. Formal charge on nitrogen?
N has +1 formal charge
12.5 g NaCl in 350.0 mL. Molarity?
0.612 M
Is HCl a strong acid or weak acid?
Strong acid
Rank from smallest to largest atomic radius: Mg, Na, Cl, K.
Cl < Mg < Na < K
15.0 g Al reacts with excess CuCl₂. How many grams Cu?
53.0 g Cu
SF₄ geometry and polarity?
Electron geometry:
Trigonal bipyramidal
Molecular geometry:
Seesaw
Polarity:
Polar
How much 12.0 M HCl makes 500 mL of 0.250 M?
M1V1=M2V2M_1V_1=M_2V_2
10.4 mL
Write the balanced neutralization reaction between HNO₃ and KOH.
HNO3+KOH→KNO3+H2O
onization energies:
IE₁ = 738, IE₂ = 1450, IE₃ = 7730 kJ/mol. What group?
Group 2 (alkaline earth metal)
25.0 g CaCO₃ decomposes. Yield = 82.5%. Mass CO₂?
9.08 g CO₂
Determine the electron geometry, molecular geometry, bond angle, and polarity of BF₃.
Electron geometry:
Trigonal planar
Molecular geometry:
Trigonal planar
Bond angle:
120°
Polarity:
Nonpolar
0.15 M Al₂(SO₄)₃ concentrations?
Al³⁺ = 0.30 M
SO₄²⁻ = 0.45 M
30.0 mL of 0.250 M HCl reacts with NaOH. How many moles of NaOH are required for complete neutralization?
0.00750 mol NaOH
Which has higher first ionization energy: N or O?
N has higher IE
A chemical reaction has a theoretical yield of 25.0 g of product. After the experiment is completed, the actual amount of product collected is 18.6 g. Calculate the percent yield of the reaction.
74.4% yield
XeF₄ geometry?
Electron geometry:
Octahedral
Molecular geometry:
Square planar
BaCl₂ + Na₂SO₄ reaction?
Precipitate forms
Ba²⁺ is limiting ion
25.0 mL of 0.400 M NaOH neutralizes H₂SO₄. How many moles of H₂SO₄ reacted?
0.00500 mol H₂SO₄
X³⁻ has the same electron configuration as Ar. Identify X.
X = P
A mixture contains only NaCl and KCl. The total mass of the mixture is 10.00 g. When the mixture reacts with excess AgNO₃, it produces 15.2 g of AgCl precipitate. Determine the mass of NaCl and the mass of KCl in the original mixture.
NaCl ≈ 4.01 g
KCl ≈ 5.99 g
AX₃E₂ geometry? polar? angle?
Electron geometry:
Trigonal bipyramidal
Molecular geometry:
T-shaped
Bond angles:
90° and 120°
Polarity:
Polar
5.00 g CaCl₂·2H₂O in 250 mL. Find Cl⁻ concentration.
0.272 M Cl⁻
35.0 mL of 0.200 M H₂SO₄ is titrated with NaOH. What volume of 0.500 M NaOH is needed to completely neutralize it?
28.0 mL NaOH