Ch 19 Physical Science Test

You can only add coefficients and can not add or take away subscripts because:

• Coefficients change the number of molecules, while subscripts change the identity of the substance.

• Subscripts are easier to change than coefficients.

• Changing coefficients changes the substance's identity.

• Coefficients and subscripts mean the same thing.

Reversible reactions are:

• reactions that proceed only in one direction

• reactions that can proceed in both forward and backward directions

• reactions that never reach equilibrium

• reactions that produce only one product

Molar mass is:

• the mass of one mole of a substance

• the number of atoms in a molecule

• the volume of one mole of a gas

• the charge of an ion

A synthesis reaction is:

• a reaction where two or more substances combine to form a single product

• a reaction where a compound breaks down into two or more simpler substances

• a reaction that involves the exchange of ions between two compounds

• a reaction that releases energy in the form of heat

Exergonic reactions are:

• reactions that release energy

• reactions that absorb energy

• reactions that require light

• reactions that occur only in plants

Reactants are:

• substances that are produced in a chemical reaction

• substances that are present before a chemical reaction and take part in it

• the energy released during a reaction

• the products formed after a reaction

Endothermic reactions are:

• reactions that absorb heat

• reactions that release heat

• reactions that produce light

• reactions that form precipitates

The two types of equilibrium are:

• Static and dynamic equilibrium

• Thermal and chemical equilibrium

• Mechanical and electrical equilibrium

• Stable and unstable equilibrium

A decomposition reaction is:

• a reaction where two or more substances combine to form a new compound

• a reaction where a compound breaks down into two or more simpler substances

• a reaction where substances exchange ions to form new compounds

• a reaction where energy is absorbed from the surroundings

What is the collision model?

• A theory explaining how particles interact during chemical reactions.

• A method for measuring temperature.

• A process for separating mixtures.

• A technique for purifying water.