Chemical Formulas & Equations
What is the total number of sulfur atoms in the formula (NH4)2SO4? (1) 1 (2) 2 (3) 3 (4) 4
(1) 1
In a sample of solid Ba(NO3)2 the ratio of barium ions to nitrate ions is (1) 1:3:2 (2) 1:2 (3) 2:1 (4) 1:6
(2) 1:2
What is the total number of hydrogen atoms in the formula 3Mg(C2H3O2)2? (1) 3 (2) 6 (3) 12 (4) 18
(2) 6
Which compound has the same empirical and molecular formula? (1) H2O2 (2) NH3 (3) C2H6 (4) Hg2Cl2
(2) NH3
The empirical formula of a compound is CH2. The molceular formula of this compound could be (1) CH4 (2) C2H2 (3) C2H4 (4) C3H3
(3) C2H4
Which chemical formula represents a compound? (1) Ca (2) Cr (3) CO (4) Co
(3) CO
What is the total number of atoms in the formula Ca(NO3)2? (1) 7 (2) 2 (3) 3 (4) 9
(4) 9
What is the empirical formula of a compound with the molecular formula C6H12O6? (1) C4H8O4 (2) C3H6O3 (3) C2H4O2 (4) CH2O
(4) CH2O
An example of an empirical formula is (1) S2H2 (2) H2O2 (3) C2Cl2 (4) CaCl2
(4) CaCl2
Which is an empirical formula? (1) C2H2 (2) C2H4 (3) Al2Cl6 (4) K2O
(4) K2O
A chemical formula is an expression used to represent (1) mixtures only (2) elements only (3) compounds only (4) elements and compounds
(4) elements and compounds
For each of the following formulas, write the name of each element and the number of atoms of that element are in the formula. (a) K3PO4 (b) 3Al(OH)3 (c) 5Fe2(SO4)3
(a) 3 potassium, 1 phosphorus, 4 oxygen (b) 1 aluminum, 3 oxygen, 3 hydrogen (c) 2 iron, 3 sulfur, 12 oxygen
For each of the following formulas, write the name of each element and the number of atoms of that element that are in the formula. (a) 2K2PO4 (b) 3Al(OH3) (c) 5Fe2(SO4)3
(a) 6 potassium, 2 phosphorus, 8 oxygen (b) 3 aluminum, 9 oxygen, 9 hydrogen (c) 10 iron, 15 sulfur, 60 oxygen
What is the qualitative and quantitative information given by the formula Ca3(PO4)2?
Qualitative information: the compound is made of calcium, phosphorus, and oxygen; phosphorus and oxygen are combined to form the polyatomic phosphate ion. Quantitative information: one unit of the compound contains three calcium atoms and two phosphate ions. Each phopsphate ion contains one phosphorus atom and four oxygen atoms.
