11th Grade Chemical Quantities and Reactions

Which of the following is true regarding the law of conservation of mass?

• It dictates that the number of atoms of each element must be the same on both sides of a chemical equation

• It states that the mass of the reactants must remain constant in order for a chemical reaction to proceed.

• It does not apply to chemical reactions.

Tags

NGSS.MS-PS1-5

Which of the following may indicate that a chemical reaction has occurred?

• release of energy as light

• a color change

• gas bubble formation

• All of the above

Tags

NGSS.MS-PS1-2

What does CH4 represent in the balanced chemical equation shown below?

C + 2H₂ → CH₄

• one atom of CH₄

• five atoms of CH₄

• one molecule of CH₄

Tags

NGSS.MS-PS1-1

Which set of coefficients will balance the equation below?

NaOH + Cu(NO₃)₂ → Cu(OH)₂ + NaNO₃

• 2, 1, 1, 2

• 1, 2, 2, 1

• 1, 1, 1, 1

Tags

NGSS.HS-PS1-7

What type of chemical reaction results in the formation of a single product?

• combustion

• synthesis

• decomposition

In the reaction :

Zn(s) + H₂SO₄(aq) → ZnSO₄(aq) + H₂(g)

What element has been displaced?

• Zn

• H

• S

• O

The reaction below is a :

Mg(s) + 2HCl(aq) → H₂(g) + MgCl₂(aq)

• synthesis reaction.

• decomposition reaction.

• single-displacement reaction.

What symbol indicates a reversible reaction?

• →

• ↑

• ←

• ⇌

In the expression 3CO₂, the numbers 3 and 2 are, respectively,

• a subscript and a coefficient.

• a coefficient and a subscript.

• two subscripts.

• two coefficients.

Which of the following equations represents the balanced equation for the reaction of iron and oxygen?

• 2Fe + O₂ → Fe₂O₃

• Fe + 3O₂ → Fe₂O₃

• 4Fe + 3O₂ → 2Fe₂O₃