Reactions and Balancing Equations

What is the balanced equation when aluminum reacts with copper(II) sulfate?

• Al + CuSO₄ --> AlSO₄ + Cu
• 2Al + 3CuSO₄ --> Al₂(SO₄)₃ + 3Cu
• Al + Cu₂S --> Al₂S + Cu
• 2Al + Cu₂SO₄ --> Al₂SO₄ + 2Cu

Tags

NGSS.HS-PS1-7

NGSS.HS-PS1-2

Zn (s)  +  2HCl  -->  ZnCl₂  +  H₂  
Choose the following statement that best explains why this chemical reaction is an oxidation-reduction reaction:

• Zn and H⁺ undergo a change of state.
• Zn loses electrons and H⁺ gains electrons.
• Zn reacts under basic conditions.
• Zn dissolves in an aqueous solution.

Tags

NGSS.HS-PS1-2

In the chemical reaction,
2H₂ + O₂ --> 2H₂O, the reactant(s) is or are:

• H₂
• H₂O
• O₂
• H₂ and O₂

Tags

NGSS.MS-PS1-1

When the equation Fe₃O₄ + Al --> Al₂O₃ + Fe is correctly balanced, what is the coefficient of Fe?

• 2
• 7
• 9
• 4

Tags

NGSS.HS-PS1-7

Compare the elements in the reaction below as they change from reactants to products.  Which answer choice correctly lists the change in oxidation number for Fe in the reaction below?
2 Fe₂O₃ --> 4 Fe + 3 O₂

• +2 to +4
• +3 to 0
• +3 to –2
• 0 to +3

Tags

NGSS.HS-PS1-7

The reaction Ca(s) + 2HCl(aq) -> H₂(g) + CaCl₂(aq) is a

• Single Replacement
• Double Replacement
• Decomposition
• Synthesis

Given the balanced equations representing two chemical reactions:
1.    I₂ + 2 KBr --> 2ICl + Br₂
2.     2NaCl --> 2 Na + Cl₂
Which types of chemical reactions are represented by these equations?

• single replacement and double replacement
• synthesis and double replacement
• synthesis and decomposition
• single replacement and decomposition

Which equation represents a decomposition reaction?

• Cu +  2AgNO₃ --> 2Ag + Cu(NO₃)₂
• CaCO₃  --> CaO  +  CO₂
• KOH  +  HCl  --> KCl  + H₂O
• 2H₂  +  O_{2  -->} 2H₂O

The reaction 2KClO₃(s) --> 2KCl(s) + 3O₂(g) is a(n)

• Decomposition
• Synthesis
• Single Replacement
• Double Replacement

Which type of reaction is the following?
3C₃H₇OH + 9O₂  --> 6CO₂ + 8H₂O

• Double Replacement
• Decomposition
• Combustion
• Single Replacement