chemistry study guide chemical equations 2020
Potassium chloride can be produced from potassium metal and chlorine gas. Which of the following is the balanced equation for the production of potassium chloride?
. 2K(s) + Cl2(g) → 2KCl(s)
An unbalanced chemical equation is shown below. CH4 + O2 CO2 + H2O Which of the following particle diagrams correctly represents the balanced form of the equation?
1 2 1 2
During combustion, methane yields carbon dioxide and water. The unbalanced equation for this reaction is: CH4 + O2 CO2 + H2O What coefficients are needed in order to balance this equation?
1, 2, 1, 2
Chemical reactions can be represented symbolically using chemical equations. In a chemical equation, reactants appear to the left of the arrow, while products appear to the right. The law of conservation of mass states that matter is neither created nor destroyed in a chemical reaction; rather, the existing atoms are just rearranged. Therefore, chemical equations must be balanced—that is, the same number of each kind of atom must be present before and after a chemical reaction. An unbalanced chemical equation is shown below. Balance the equation according to the law of conservation of mass.
16 18
Which coefficients should be used to balance the following synthesis reaction?
2 1 1
The chemical equation below shows the formation of ammonia from nitrogen and hydrogen gases. N2 + H2 NH3 However, the equation shown is not balanced. Which of the following particle diagrams shows the correct balanced form of the equation?
2 3 2
The chemical equation below shows the process of forming water. Balance the equation by calculating the coefficients. H2 + O2 H2O
2, 1, 2
Which of the following sets of coefficients correctly balances the following chemical equation? Al(OH)3 Al2O3 + H2O
2; 1; 3
What coefficients must be used to balance the following chemical reaction? KClO3 KCl + O2
2; 2; 3
Which of the following sets of coefficients correctly balances the following chemical equation? Fe + Cl2 FeCl3
2; 3; 2
Aluminum (Al) combines with silver sulfide (Ag2S) to form aluminum sulfide (Al2S3) and silver (Ag) during a chemical reaction.Which of the following shows the balanced chemical equation for this reaction?
2Al + 3Ag2S Al2S3 + 6Ag
Potassium (K) combines with magnesium bromide (MgBr2) to form potassium bromide (KBr) and magnesium (Mg) during a chemical reaction.Which of the following shows the balanced chemical equation for this reaction?
2K + MgBr2 2KBr + Mg
Potassium iodide (KI) combines with mercury chloride (HgCl2) to form potassium chloride (KCl) and mercury iodide (HgI2) during a chemical reaction.Which of the following shows the balanced chemical equation for this reaction?
2KI + HgCl2 2KCl + HgI2
Lithium and oxygen react to form lithium oxide. What is the balanced equation for this reaction?
4Li + O2 → 2Li2O
Calcium carbonate can be used medicinally in vitamins as a calcium supplement or as an antacid. It is formed by bubbling carbon dioxide gas (CO2) through a solution of calcium hydroxide, Ca(OH)2. In addition to calcium carbonate (CaCO3), this reaction also produces water (H2O).Which of the following equations shows the correct balanced equation for this reaction?
Ca(OH)2 + CO2 → CaCO3 + H2O
Which of the following chemical equations is correctly balanced?
K2S + I2 → 2 KI + S 2 C2H4O + 5 O2 → 4 CO2 + 4 H2O
Which of the following chemical equations is correctly balanced?
MgCl2 → Mg + Cl2 2 C3H6 + 9 O2 → 6 CO2 + 6 H2O
Hydrazine (N2H4) is a chemical compound used in rocket fuel. Which of the following represents the correct balanced equation for the reaction of hydrazine liquid with oxygen gas to produce nitrogen gas and steam?
N2H4 + O2 N2 + 2H2O
PbCl2 Pb + Cl2 Does the chemical reaction shown above obey the law of conservation of mass?
Yes, because the equation is balanced.
Based on the models, was mass conserved in this chemical reaction?
Yes, because the number of each type of atom is the same in the products as it is in the reactants.
According to the law of conservation of mass, the mass of the reactants in a reaction must the mass of the products in a reaction.
be equal to
A sample of copper powder is heated in an evaporating dish using a Bunsen burner. If the mass of the powder in the evaporating dish increases after heating, this indicates that
the copper must have combined with another substance.