Random Topics
Conversions
Nomenclature
The Mole & Balancing Equation
Stoichiometry
100
An isotope of element X has 20 protons and 22 neutrons. What is the mass number, and what element is X?
Mass number = 42; Element = Calcium (Ca)
100
The density of an unknown liquid is 1.15 g/mL. What is the mass of 250 mL of this liquid?
287.5 g
100
Name the compound CuSO₄·5H₂O.
Copper(II) sulfate pentahydrate
100
Calculate the number of moles in 18.0 g of water.
1.00 mol of water
100
How many grams of CO₂ are produced from 0.75 mol of propane (C₃H₈) combusted completely? (C₃H₈ + 5O₂ → 3CO₂ + 4H₂O)
99 g CO₂
200
When magnesium (Mg²⁺) combines with nitrogen (N³⁻), what is the chemical formula of the compound?
Mg₃N₂
200
Convert 45.0 g of water to pounds. (1 lb = 453.6 g)
0.099 lb
200
Write the chemical formula for iron (III) carbonate.
Fe₂(CO₃)₃
200
How many atoms are in 2.50 moles of iron?
1.51 × 10²⁴ atoms
200
If 5.00 g of H₂ reacts with excess O₂, how many grams of H₂O are produced? (2H₂ + O₂ → 2H₂O)
44.8 g H₂O
300
Write the electron configuration for aluminum (Al).
1s² 2s² 2p⁶ 3s² 3p¹
300
Convert 75.0 km/hr to m/s. (1 km = 1000 m; 1 hr = 3600 s)
20.8 m/s
300
Name the compound N₂O₄.
Dinitrogen tetroxide
300
Balance the equation:
Fe + O₂ → Fe₂O₃
4Fe + 3O₂ → 2Fe₂O₃
300
How many molecules of NH₃ can be produced from 4.00 g of H₂? (N₂ + 3H₂ → 2NH₃)
7.95 × 10²³ molecules
400
Predict the formula of the compound formed between aluminum and oxygen.
Al₂O₃
400
A piece of metal has a mass of 65.4 g and a volume of 8.40 cm³. What is its density in g/cm³?
7.79 g/cm³
400
Name the compound Pb(C₂H₃O₂)₄.
Lead (IV) acetate
400
How many moles of oxygen molecules are required to completely react with 4.0 mol of ammonia in: 4NH₃ + 5O₂ → 4NO + 6H₂O?
5.0 mol O₂
400
In the reaction 2KClO₃ → 2KCl + 3O₂, how many grams of O₂ form from 15.0 g of KClO₃?
5.88 g O₂
500
An atom has 18 electrons, 18 protons, and 22 neutrons. Identify the isotope and whether it’s neutral, cation, or anion.
Argon-40; neutral atom
500
The following graph was generated using mass and volume data for an unknown solid. Use the graph to determine the approximate volume (in mL) of a 50 g of this solid.
~ 10 mL
500
Write the formula for ammonium dichromate.
(NH₄)₂Cr₂O₇
500
Calculate the number of oxygen atoms in 3.5 moles of H₂O.
2.108 × 10²⁴ oxygen atoms
500
A reaction theoretically yields 25.0 g of product but only 18.7 g is obtained. What is the percent yield?
74.8%