Question 1

In a balanced chemical equation

Accepted Answer

In a balanced chemical equation, the law of conservation of mass dictates that there must be an equal number of each type of atom on both sides of the equation, ensuring mass is conserved throughout the reaction.

Question 2

When the reaction shown is correctly balanced,the coefficients are: ________ KClO₃ → ________ KCl + ________ O₂

Accepted Answer

The balanced equation is:
2KClO3 → 2KCl + 3O2, which means the coefficients are 2, 2, and 3 respectively.

Question 3

Which statement regarding balanced chemical equations is not true?

Accepted Answer

Subscripts represent the number of atoms in a molecule and cannot be changed in order to balance an equation. Only coefficients can be added or adjusted to balance the equation.

Question 4

Which is the correct equation for the reaction of magnesium with hydrochloric acid to produce hydrogen and magnesium chloride?

Accepted Answer

The correct equation is Mg + 2 HCl → H₂ + MgCl₂, which matches choice A when considering the subscript formatting issue. This equation correctly balances the magnesium, hydrogen, and chlorine atoms on both sides of the reaction.

Question 5

When the reaction shown is correctly balanced,the coefficients are: ________ Li + ________ Br₂ → ________ LiBr

Accepted Answer

The balanced equation is 2 Li + 1 Br2 → 2 LiBr, ensuring the same number of each type of atom on both sides.

Question 6

Which of the following equations is not balanced?

Accepted Answer

The equation A is not balanced because the number of oxygen atoms on the reactant side (O2) does not match the number on the product side (7 CO2 + 8 H2O).

Question 7

When the reaction shown is balanced,there are ________ atoms of oxygen and ________ atoms of hydrogen on each side. _______ (NH₄)₂SO₄(aq)+ _______ Ba(C₂H₃O₂)₂(aq)→ _______ BaSO₄(s)+ _______ NH₄C₂H₃O₂(aq)

Accepted Answer

There are 8 atoms of oxygen and 14 atoms of hydrogen on each side. To see this, count the number of oxygen atoms in each compound: 1 in H2SO4, 12 in Ba(C2H3O2)2·2H2O, 1 in BaSO4, and 4 in NH4C2H3O2. Count the number of hydrogen atoms in each compound: 2 in H2SO4, 13 in Ba(C2H3O2)2·2H2O, 0 in BaSO4, and 2 in NH4C2H3O2. Then make sure the coefficients in front of each compound are such that the number of atoms on each side is the same.

Question 8

Consider the balanced equation shown and identify the statement that is not true. Na₂SO₄(aq)+ BaCl₂(aq)→ 2 NaCl(aq)+ BaSO₄(s)

Accepted Answer

The statement that is not true is A) The coefficient of sodium sulfate is one. The coefficient of Na2SO4 is actually 0, meaning there is no sodium sulfate in the products. Choice E is true because NaCl could also be written as Na+Cl-, which are the ions present in solution. The other statements in the question are true.

Question 9

When the following reaction is balanced,the coefficient in front of carbon dioxide is: ________ C₅H₁₂ + ________ O₂ → ________ CO₂ + ________ H₂O

Accepted Answer

The number of carbon atoms on the reactant side must equal the number of carbon atoms on the product side. There are 5 carbon atoms on the reactant side, so there must be 5 carbon atoms on the product side. The only product that contains carbon is carbon dioxide, so the coefficient in front of carbon dioxide must be 5.

Question 10

The balanced equation for the reaction occurring when iron(III)oxide,a solid,is reduced with pure carbon to produce carbon dioxide and molten iron is

Accepted Answer

The balanced equation for the reduction of iron(III) oxide with carbon is 2 Fe₂O₃(s) + 3 C(s) → 4 Fe(l) + 3 CO₂(g).

Question 11

Consider the reaction shown and identify the statement that is not true. CaCO₃(s) CaO(s)+ CO₂(g)

Accepted Answer

The given reaction does not involve water as a reactant or a product, so it is not necessary for water to be present for this reaction to occur.

Question 12

When the reaction shown is correctly balanced,the coefficients are: ________ C₆H₁₄(l)+ ________ O₂(g)→ ________ CO₂(g)+ ________ H₂O(g)

Accepted Answer

By counting the atoms on both sides, we can determine the coefficients needed to balance the equation. Starting with carbon, we see that there is one on both sides, so the first coefficient is 1. For hydrogen, there are 2 on the left and 12 on the right, so the coefficient for H2O should be 6. For oxygen, there are 12 on the left and 2 on the right, so the coefficient for O2 should be 6. Finally, for sulfur, there is 1 on each side, so the coefficient for CS2 should be 1. Thus, the balanced equation is:

CS2(l) + 6O2(g) → 2COS(g) + 4H2SO4(g)

which corresponds to choice B.

Question 13

In the correctly balanced reaction,the coefficient for H₂O is: ________ Al(OH)₃ + ________ H₂SO₄ → ________ Al₂(SO₄)₃ + ________ H₂O

Accepted Answer

The balanced chemical equation is 2 Al(OH)3 + 3 H2SO4 → 1 Al2(SO4)3 + 6 H2O.

Question 14

When the reaction shown is correctly balanced,the coefficients are: ________ HNO₃ + ________ KOH → ________ KNO₃ + ________ H₂O

Accepted Answer

The balanced chemical equation is HNO3 + KOH → KNO3 + H2O, which corresponds to a 1:1:1:1 stoichiometry.

Question 15

In a precipitation reaction the insoluble product can be identified by the symbol

Accepted Answer

In a precipitation reaction, two aqueous solutions are mixed together to form an insoluble product that precipitates out of solution. The insoluble product is in the solid state, so its symbol is (s), indicating that it is a solid. Therefore, the best choice is D, (s).

Question 16

When the reaction shown is correctly balanced,the coefficients are: ________ HBr + ________ Ca(OH)₂ → ________ CaBr₂ + ________ H₂O

Accepted Answer

The equation shows that there are 2 hydrogen atoms on the left and 1 on the right, so the coefficient for HBr must be 2 to balance the hydrogen. There is 1 calcium on each side, so the coefficient for Ca(OH)2 must be 1. There is 1 sulfur on each side, so the coefficient for CaBr2 must also be 1. Finally, there are 2 oxygen atoms on the right and none on the left, so the coefficient for H2O must be 2 to balance the oxygen. Therefore, the correct coefficients are 2, 1, 1, 2, which corresponds to choice C.

Question 17

The scientific principle which is the basis for balancing chemical equations is

Accepted Answer

Balancing chemical equations is based on the Law of Conservation of Mass, which states that matter cannot be created or destroyed in a chemical reaction. Therefore, the number of atoms of each element must be the same on both sides of the equation.

Question 18

Which of the following equations is not balanced?

Accepted Answer

The equation SO₂ + O₂ → SO₃ is not balanced as the total number of sulfur atoms on the left side is 1 while on the right side it is 2. Therefore, D is the correct answer.

Question 19

The balanced equation for the reaction occurring when calcium nitrate solution is mixed with sodium phosphate solution is

Accepted Answer

The balanced equation correctly represents the reaction where calcium phosphate precipitates as a solid and sodium nitrate remains in solution.

Question 20

When the following reaction is balanced,the coefficient in front of oxygen is: ________ C₈H₁₈ + ________ O₂ → ________ CO₂ + ________ H₂O

Accepted Answer

The balanced equation is: CS2 + 3O2 → CO2 + 2SO2. This means the coefficient in front of oxygen (O2) is 3.

Quiz 5: Classification and Balancing of Chemical Reactions

In a balanced chemical equation

When the reaction shown is correctly balanced,the coefficients are: KClO₃ → KCl + O₂

Which statement regarding balanced chemical equations is not true?

Which is the correct equation for the reaction of magnesium with hydrochloric acid to produce hydrogen and magnesium chloride?

When the reaction shown is correctly balanced,the coefficients are: Li + Br₂ → LiBr

Which of the following equations is not balanced?

When the reaction shown is balanced,there are ____ atoms of oxygen and atoms of hydrogen on each side. _ (NH₄) ₂SO₄(aq) + _ Ba(C₂H₃O₂) ₂(aq) → _ BaSO₄(s) + _____ NH₄C₂H₃O₂(aq)

Consider the balanced equation shown and identify the statement that is not true. Na₂SO₄(aq) + BaCl₂(aq) → 2 NaCl(aq) + BaSO₄(s)

When the following reaction is balanced,the coefficient in front of carbon dioxide is: C₅H₁₂ + O₂ → CO₂ + H₂O

The balanced equation for the reaction occurring when iron(III) oxide,a solid,is reduced with pure carbon to produce carbon dioxide and molten iron is

Consider the reaction shown and identify the statement that is not true. CaCO₃(s) CaO(s) + CO₂(g)

When the reaction shown is correctly balanced,the coefficients are: C₆H₁₄(l) + O₂(g) → CO₂(g) + H₂O(g)

In the correctly balanced reaction,the coefficient for H₂O is: Al(OH) ₃ + H₂SO₄ → Al₂(SO₄) ₃ + H₂O

When the reaction shown is correctly balanced,the coefficients are: HNO₃ + KOH → KNO₃ + H₂O

In a precipitation reaction the insoluble product can be identified by the symbol

When the reaction shown is correctly balanced,the coefficients are: HBr + Ca(OH) ₂ → CaBr₂ + H₂O

The scientific principle which is the basis for balancing chemical equations is

Which of the following equations is not balanced?

The balanced equation for the reaction occurring when calcium nitrate solution is mixed with sodium phosphate solution is

When the following reaction is balanced,the coefficient in front of oxygen is: C₈H₁₈ + O₂ → CO₂ + H₂O

Quiz 5: Classification and Balancing of Chemical Reactions

In a balanced chemical equation

When the reaction shown is correctly balanced,the coefficients are: ________ KClO3 → ________ KCl + ________ O2

Which statement regarding balanced chemical equations is not true?

Which is the correct equation for the reaction of magnesium with hydrochloric acid to produce hydrogen and magnesium chloride?

When the reaction shown is correctly balanced,the coefficients are: ________ Li + ________ Br2 → ________ LiBr

Which of the following equations is not balanced?

When the reaction shown is balanced,there are ________ atoms of oxygen and ________ atoms of hydrogen on each side. _______ (NH4) 2SO4(aq) + _______ Ba(C2H3O2) 2(aq) → _______ BaSO4(s) + _______ NH4C2H3O2(aq)

Consider the balanced equation shown and identify the statement that is not true. Na2SO4(aq) + BaCl2(aq) → 2 NaCl(aq) + BaSO4(s)

When the following reaction is balanced,the coefficient in front of carbon dioxide is: ________ C5H12 + ________ O2 → ________ CO2 + ________ H2O

The balanced equation for the reaction occurring when iron(III) oxide,a solid,is reduced with pure carbon to produce carbon dioxide and molten iron is

Consider the reaction shown and identify the statement that is not true. CaCO3(s) CaO(s) + CO2(g)

When the reaction shown is correctly balanced,the coefficients are: ________ C6H14(l) + ________ O2(g) → ________ CO2(g) + ________ H2O(g)

In the correctly balanced reaction,the coefficient for H2O is: ________ Al(OH) 3 + ________ H2SO4 → ________ Al2(SO4) 3 + ________ H2O

When the reaction shown is correctly balanced,the coefficients are: ________ HNO3 + ________ KOH → ________ KNO3 + ________ H2O

In a precipitation reaction the insoluble product can be identified by the symbol

When the reaction shown is correctly balanced,the coefficients are: ________ HBr + ________ Ca(OH) 2 → ________ CaBr2 + ________ H2O

The scientific principle which is the basis for balancing chemical equations is

Which of the following equations is not balanced?

The balanced equation for the reaction occurring when calcium nitrate solution is mixed with sodium phosphate solution is

When the following reaction is balanced,the coefficient in front of oxygen is: ________ C8H18 + ________ O2 → ________ CO2 + ________ H2O

When the reaction shown is correctly balanced,the coefficients are: KClO₃ → KCl + O₂

When the reaction shown is correctly balanced,the coefficients are: Li + Br₂ → LiBr

When the reaction shown is balanced,there are ____ atoms of oxygen and atoms of hydrogen on each side. _ (NH₄) ₂SO₄(aq) + _ Ba(C₂H₃O₂) ₂(aq) → _ BaSO₄(s) + _____ NH₄C₂H₃O₂(aq)

Consider the balanced equation shown and identify the statement that is not true. Na₂SO₄(aq) + BaCl₂(aq) → 2 NaCl(aq) + BaSO₄(s)

When the following reaction is balanced,the coefficient in front of carbon dioxide is: C₅H₁₂ + O₂ → CO₂ + H₂O

Consider the reaction shown and identify the statement that is not true. CaCO₃(s) CaO(s) + CO₂(g)

When the reaction shown is correctly balanced,the coefficients are: C₆H₁₄(l) + O₂(g) → CO₂(g) + H₂O(g)

In the correctly balanced reaction,the coefficient for H₂O is: Al(OH) ₃ + H₂SO₄ → Al₂(SO₄) ₃ + H₂O

When the reaction shown is correctly balanced,the coefficients are: HNO₃ + KOH → KNO₃ + H₂O

When the reaction shown is correctly balanced,the coefficients are: HBr + Ca(OH) ₂ → CaBr₂ + H₂O

When the following reaction is balanced,the coefficient in front of oxygen is: C₈H₁₈ + O₂ → CO₂ + H₂O