What are the purposes of a chemical equation?
to show how substances in a chemical reaction interact
to shorten the explanation of a chemical reaction
to help keep track of atoms in a chemical reaction
Nitrogen gas reacts with hydrogen to produce ammonia. Use the chemical equation to complete the statements.
N2 + 3H2 ? 2NH3
There are 2 nitrogen atoms on the product side.
There are 6 hydrogen atoms on the reactant side.
The inflation of airbags is due to the breakdown of a single chemical substance into two separate substances.
Two molecules of sodium azide (NaN3) break down into sodium (Na) and nitrogen gas (N2) during the reaction.
How many sodium (Na) atoms are produc
2 Na atoms
Identify the number of atoms on the reactant side of the chemical equation.
Fe2O3 + 3H2 ? 2Fe + 3H2O
There are 2 Fe (iron) atoms.
There are O (oxygen) atoms.
There are H (hydrogen) atoms.
In your own words, describe the purpose of using a chemical equation.
Chemical equations show how chemicals interact when a reaction occurs.
Chemical equations use symbols and formulas to show the chemical reaction so that chemical names do not need to be written out.
Chemical equations help keep track of all elements and t
Marcia is given an incomplete chemical equation that includes the number of nitrogen atoms present in the products of the reaction. How can she conclude that the reaction started with three nitrogen atoms?
There are three nitrogen atoms in the products.
The law of conservation of mass states that the amount of substance should be the same before and after a reaction.
Sulfurous acid, H2SO3, breaks down into water (H2O) and sulfur dioxide (SO2).
If only one molecule of sulfurous acid was involved in a chemical reaction, how many sulfur (S) atoms would be in the products?
1 atom of sulfur
Calcium carbonate can break down to form calcium oxide and carbon dioxide.
CaCO3 ? CaO + CO2
The oxygen atoms on the product side are
balanced because the total number of oxygen atoms is 3.
The product side of a chemical reaction is shown.
? 7Ti2(SO4)3
Which number represents a coefficient?
7
Which is the correctly balanced equation for the reaction of rust, Fe2O3, and hydrochloric acid, HCl?
Fe2O3 + 6 HCl ? 2 FeCl3 + 3 H2O
Min is asked to balance the equation below.
Original: Ca3P2 + H2O ? Ca(OH)2 + PH3
Min's result: Ca3P2 + H2O ? Ca3(OH)2 + PH3
Which best describes Min's method for balancing the chemical equation?
It is incorrect, because the identity of the original product has changed.
Rust results from iron's reaction to oxygen. An iron nail gains mass when it rusts. How does this reaction support the law of conservation of mass?
The mass of the rusted nail equals the mass of iron and the oxygen from the air it reacted with to form the rust.
Leslie incorrectly balances an equation as 2C4H10 + 12O2 ? 8CO2 + 10H2O.
Which coefficient should she change?
12
Which symbol in a chemical equation separates the reactants from the products?
?
Thirty grams of lead oxide and fifteen grams of ammonia react completely to produce solid lead, nitrogen gas, and liquid water. What will be approximate mass of all three products?
45 g
Which are the products in the equation CH3SH + 4O2 ? CO2 + SO2 +2H2O? Check all that apply.
CO2
SO2
H2O
For the equation 3Cu + 8HNO3 ? 3Cu(NO3)2 + 2NO + 4H2O, how many units of NO3 are represented on the products side?
6
What can the arrow in a chemical reaction be translated to mean? Check all that apply.
yields
react to form