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Exam:
6 quizzes
Rank the oxygen species O₂⁺, O₂ and O₂⁻ by bond length, from the shortest. New
High School (11–12) · Molecular Orbitals and Hydrogen Bonds
NEET, Board Exam
StemPy LabStemPy Lab
Medium
Analysis shows that a colourless gas is 30.4% nitrogen and 69.6% oxygen, and a gas-density test puts its molar mass at 92 g mol⁻¹. Which formula fits both results? New
High School (11–12) · Stoichiometry and Concentration, The Mole Concept
NEET, Board Exam, AP, A-Level, IB
StemPy LabStemPy Lab
Medium
A balloon holds 4 g of hydrogen and 16 g of oxygen. A spark sets off 2H₂ + O₂ → 2H₂O. Which gas runs out, and how much water is made? New
High School (9–10), General · Chemical Equations
NEET, Board Exam, AP, A-Level, IB
StemPy LabStemPy Lab
Hard
A laser gives out 2.0 mW of light at 620 nm. About how many photons leave it each second? (1 eV = 1.6 × 10⁻¹⁹ J.)
High School (11–12) · Light, Atomic Spectra and the Bohr Model
NEET, Board Exam, AP, A-Level, IB
StemPy LabStemPy Lab
Hard
Which line of He⁺ has the same wavelength as the first Balmer line of hydrogen, n = 3 → 2?
High School (11–12) · Light, Atomic Spectra and the Bohr Model
JEE Main, NEET, BITSAT, WBJEE, Board Exam
StemPy LabStemPy Lab
Hard
10 g of hydrogen is mixed with 64 g of oxygen and sparked. Water forms with hydrogen and oxygen in the ratio 1 : 8. What mass of water forms?
High School (9–10), General · Laws of Chemical Combination
NEET, Board Exam, AP, A-Level, IB
StemPy LabStemPy Lab
Hard