Chemical Reactions

Front

When a scientist mixed two chemicals, an exothermic reaction takes place. Which of the following would be proof that the reaction was exothermic? Options: a change of color, a change of state, a temperature decrease, a temperature increase

Back

a temperature increase

Front

What types of reactions absorb and release heat? Options: acidic and basic, endothermic and exothermic, endothermic and heat transfusion, covalent and ionic

Back

endothermic and exothermic

Front

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

Back

heat

Front

Which of the following is a chemical change? Options: water freezes to form ice, sugar dissolves in water, gasoline burns in a car engine, a piece of metal expands when it is heated

Back

gasoline burns in a car engine

Front

In the reaction methane + oxygen turns into carbon dioxide + water, the methane and oxygen are called _______________.

Back

reactants

Front

A change in the shape of an object is an example of _________________

Back

a physical change

Front

What type of change occurs when a new substance is formed that has different properties from the original substances?

Back

chemical change

Front

Increasing the concentration of a reactant in a chemical reaction will _____________.

Back

increase the rate of the reaction

Front

Which of the following represents a chemical change? Options: cutting a piece of paper with scissors, cooling a mixture of air and kerosene vapor to obtain liquid kerosene, burning a piece of notebook paper in the presence of oxygen, heating water over a flame to its boiling point

Back

burning a piece of notebook paper in the presence of oxygen

Front

Which of the following is an example of a physical change? souring milk, mixing baking soda and vinegar, rusting metal, mixing oil and vinegar

Back

mixing oil and vinegar