WorksheetsReactions, Balancing, and Stoichiometry Basics
Total questions: 25
Worksheet time: 1hrs 15mins
The Law of Conservation of Matter
tells how many atoms of an element are contained in one molecule or formula unit.
the starting materials in a chemical reaction
the new substances that are formed in a chemical reaction
A law stating that atoms are not created or destroyed during a chemical reaction.
Balance this equation
_Al +_HCl --> _H2 +_AlCl3
2,6,3,2
it's already balanced
4,12,3,4
2,1,4,5
What are the coefficients that would properly balance this equation?
__Ca + __H2O --> __Ca(OH)2 + __H2
2,1 --> 2,1
1,2 --> 1,1
1,2 --> 2,4
1,2 --> 2,1
Fe + O2 -> Fe2O3
NH3 + HCl → NH4Cl
PbCl2 + AgNO3 → Pb(NO3)2 + AgCl
How are a mole aluminum and zinc the same?
they have the same number of atoms - 6.02 x 1023
they have the same molar mass
How many moles of oxygen are consumed if 8 moles H2 are used?
Where are the numbers for a mole ratio found?
They are part of the chemical formulas for the reactants / products.
They are given in the problem.
They are found on the periodic table for those elements.
They are found as coefficients in the reaction's balanced chemical equation.
2 C2H6 + 7 O2 → 4 CO2 + 6 H2O
A problem asks how many moles of oxygen gas are needed to react completely with 6 moles of ethane (C2H6). What is the final answer for this problem?
13 mol C2H6
3 mol O2
21 mol O2
42 mol O2
Actual yield = 62g
Calculate the percent yield.
