Chemical Reactions/Equations

Which of the following is a chemical change?

• water freezes to form ice
• sugar dissolves in water
• gasoline burns in a car engine
• a piece of metal expands when it is heated

Which is the name of the kind of solid substance formed in this figure?  

• aqueous 
• precipitate
• acid
• synthesis 

the starting materials in a chemical reaction

• Products
• Reactants
• Starters
• Enders

A substance that is formed as the result of a chemical reaction

• Product

• Reactant

• Starters

• Enders

The symbolic representation of a chemical reaction

• Long Hand

• Short Hand

• Electron Configuration

• Chemical Equation

When a scientist mixed two chemicals, an exothermic reaction takes place. Which of the following would be proof that the reaction was exothermic?

• a change of color
• a change of state
• a temperature decrease
• a temperature increase

A scientist combines chemicals and produces an exothermic reaction. What byproduct of this reaction would show that it is exothermic?

• heat
• coolness
• a precipitate
• gas bubbles

At the end of chemical reactions, what is the total mass of the reactants compared to the total mass of the products?

• the product is doubled
• the product is half the mass of the reactants
• the mass is the same
• the mass changes depending on the reaction

What happens in an Exothermic reaction?

• More energy is released
• Less energy is released
• The substance's temperature stays the same
• The substance gets colder

The substances listed on the right side of a chemical equation are the

• Yields
• Reactants
• Products
• Precipitates