The Mole
What is the molar mass of (NH4)3PO4?
149.12 g/mol
What is the empirical formula for the molecule octane, C8H18?
C4H9
Identify the reactants for the reaction: NaOH + HCl --> H2O + NaCl
NaOH and HCl
A chemical bond between atoms results from the attraction between electrons and _________.
protons
The molar mass of CS2 is 76.14 g/mol. How many grams of CS2 are present in 10.00 mol?
761.4 g
Calculate the percent composition of MgCl2.
%Mg = 25.51% and %Cl = 74.49%
According to the law of conservation of mass, the total mass of the reacting substance is ________.
always equal to the total mass of the products
If electrons involved in bonding spend most of the time closer to one atom rather than the other, the bond is ______.
Polar covalent
Convert 2.5 mole of silver to atoms.
1.505 x 1024 atom
The empirical formula of a hydrocarbon is found to be CH. Laboratory procedures have found that the molar mass of the compound is 78 g/mol. What is the molecular formula of this compound?
C6H6
In an equation, the symbol for a substance in water solution is followed by
(aq)
If two covalently bonded atoms are identical, the bond is
nonpolar covalent
The molar mass of LiF is 25.94 g/mol. How many moles of LiF are present in 8.92 g?
0.344 mol
The percent composition of a compound was found to be 63.5% silver, 8.2% nitrogen, and 28.3% oxygen. Determine the compound's empirical formula.
AgNO3
Magnesium reacts with hydrochloric acid. What observation indicated that a reaction has taken place?
Bubbling (evolution of a gas)
Draw the Lewis Structure of NH3
H-N-H
H
Convert 3.51 x 1025 molecules of water to moles.
58.31 mol
What is the empirical formula of a compound which consists of 89.14% Au and 10.80% O?
Au2O3
Balance the chemical equation C7H14 + O2 --> CO2 + H2O
2C7H14 + 21O2 --> 14CO2 + 14H2O
A substance has a low boiling and melting point, is soft, and insoluble in water. Identify the bond in this substance.
nonpolar covalent