#1
Which of the following is a characteristic of a chemical reaction?
Change in temperature
ExplanationIndication of energy exchange during reaction.
#2
What is the product of the reaction between sodium hydroxide (NaOH) and hydrochloric acid (HCl)?
Sodium chloride (NaCl) and water (H₂O)
ExplanationResulting compounds after neutralization.
#3
Which of the following is a characteristic of an exothermic reaction?
Release of heat
ExplanationEnergy released to surroundings.
#4
What is the law of conservation of mass in chemical reactions?
Mass cannot be created nor destroyed in a chemical reaction
ExplanationTotal mass remains constant in reactions.
#5
Which of the following is a product of the combustion of hydrocarbons?
Carbon dioxide (CO₂) and water (H₂O)
ExplanationResulting substances from burning hydrocarbons.
#6
What is the balanced chemical equation for the reaction between hydrogen gas and oxygen gas to form water?
2H₂ + O₂ → 2H₂O
ExplanationBalanced representation of reactants and products.
#7
What type of reaction occurs when two substances combine to form a single product?
Synthesis reaction
ExplanationFormation of a compound from simpler substances.
#8
Which of the following factors affect the rate of a chemical reaction?
All of the above
ExplanationVarious factors influencing reaction speed.
#9
What is the name of the reaction in which a single compound breaks down into two or more simpler substances?
Decomposition reaction
ExplanationComplex molecule disassembling.
#10
Which of the following is NOT a type of chemical reaction?
Catalytic reaction
ExplanationProcess involving catalysts, not a reaction type.
#11
In a redox reaction, which substance undergoes reduction?
The oxidizing agent
ExplanationSubstance gaining electrons, being reduced.
#12
What is the chemical formula for sodium bicarbonate?
NaHCO₃
ExplanationChemical formula of bicarbonate salt.
#13
Which of the following is a characteristic of a double displacement reaction?
Two reactants exchange ions to form two new compounds
ExplanationExchange of ions between compounds.
#14
Which of the following statements about enzymes in chemical reactions is true?
Enzymes lower the activation energy of a reaction
ExplanationBiological catalysts reducing energy barrier.