Balancing Chemical Equations Practice

Which statement best describes balancing equations and the law of conservation of mass?

• There are more atoms in the reactants than in the products, and the total mass is the same in the reactants and in the products.

• The number of atoms is the same in the reactants and in the products, and the total mass is the same in the reactants and in the products.

• There are fewer atoms in the reactants than in the products, and the total mass is less in the reactants than in the products.

• There are more atoms in the reactants than in the products, and the total mass is higher in the reactants than in the products.

Tags

NGSS.MS-PS1-5

Robert is balancing equations with his study group. He is unsure about one equation because each member of the study group came up with a different answer. Which is the proper way to balance the equation Ca(OH)₂ + H₃PO₄ → Ca₃(PO₄)₂ + H₂O?

• H₃PO₄ → Ca₃(PO₄)₂ + H₂O?

• Ca(OH)₂ + H₃PO₄ → Ca₃(PO₄)₂ + 6H₂O

• 3Ca(OH)₂ + 2H₃PO₄ → Ca₃(PO₄)₂ + 3H₂O

• Ca(OH)₂ + 2H₃PO₄ → Ca₃(PO₄)₂ + 6H₂O

Tags

NGSS.MS-PS1-5

Charlie is balancing an equation. She has identified the atoms and counted the number of each in the reactants and products. What would Charlie adjust to make the number of atoms in the reactants the same as the number of atoms in the products?

• coefficients

• subscripts

• superscripts

• parentheses

Tags

NGSS.MS-PS1-5

One half of a balanced chemical equation is shown.

3Mg(OH)₂ + 2H₃PO₄

Which lists the numbers of each atom the other half of the equation would contain?

• 3 Mg, 2 P, 14 O, 12 H

• Mg, 2 P, 14 O, 6 H

• 3 Mg, 8 P, 7 O, 6 H

• 6 Mg, 6 P, 2 O, 12 H

Tags

NGSS.MS-PS1-1

NGSS.MS-PS1-2

NGSS.MS-PS1-5

The amount of oxygen in the reactants is 4 atoms. In the products, the oxygen is distributed to water (H₂O) and O₂ gas. Which coefficients would be placed in front of water and oxygen?

• 2 in front of water and 2 in front of oxygen

• 1 in front of water and 2 in front of oxygen

• 1 in front of water and 1 in front of oxygen

• 2 in front of water and 1 in front of oxygen

Tags

NGSS.MS-PS1-5

Which is the balanced equation for V₂O₅ + CaS → CaO + V₂S₅?

• V₂O₅ + CaS → CaO + V₂S₅

• 5V₂O₅ + 5CaS → 10CaO + 5V₂S₅

• 3V₂O₅ + 3CaS → 3CaO + 3V₂S₅

• V₂O₅ + 5CaS → 5CaO + V₂S₅

Tags

NGSS.MS-PS1-5

The equation for water is H₂ +O₂ → H₂O. To balance the equation, which coefficient should be placed in front of H₂ and H₂O?

• 1

• 2

• 3

• 4

Tags

NGSS.MS-PS1-5

When balanced, which equation would have the coefficient 3 in front of any of the reactants?

• Zn + HCl --> ZnCl₂ + H₂

• H₂SO₄ + B(OH)₃ --> B₂(SO₄)₃ + H₂O

• Fe + AgNO₃ --> Fe(NO₃)₂ + Ag

• C₂H₄O₂ + O₂ --> CO₂ +H₂O

Tags

NGSS.MS-PS1-5

Is the following equation balanced?
2C₂H₂ + 5O₂ --> 4CO₂ + 2H₂O

• yes

• no

Tags

NGSS.MS-PS1-5

Which of the following shows the correct way to balance the chemical equation?
Fe + O₂ -> Fe₂O₃

• 4Fe + 3O₂ -> 2Fe₂O₃

• 2 Fe + 3O₂ -> Fe₂O₆

• 4 Fe + O₆ -> 2Fe₂O₃

• None of the options are correctly balanced.

Tags

NGSS.MS-PS1-5