Ch. 6 Test Part 1 Regular Biology Test

______ represents a formula for a chemical compound.

• H
• P
• C
• 

The total number of atoms in a molecule of sucrose is? Sucrose chemical formula is below.

• 11
• 12
• 22
• 45

A chemical reaction is a process by which atoms or groups of atoms in substances are __________.

• dissolved in other substances.
• ionized by the loss of protons.
• mixed together with atoms in other substances.
• reorganized into different substances.

Two substances are combined and heat is produced. Does this provide evidence that a chemical reaction took place?

• No, because heat is not a chemical.
• No, because this would be a physical change.
• Yes, because energy is absorbed.
• Yes, because energy is released.

A molecule of water (H2O) has which bonds?

• 1 covalent bond
• 2 covalent bonds
• 1 ionic bond
• 2 ionic bonds

What makes a water molecule polar?

• Water has the ability to be frozen.
• The pH of pure water varies with the temperature.
• A water molecule has a slight charge on each end.
• A water molecule is made up of three atoms.

Surface tension is a result of ____________.

• Ionic bonds forming in salt water.
• Covalent bonds forming between hydrogen and oxygen.
• Hydrogen bonds forming between water molecules.
• Water reaching its freezing point.

When added to water, how does an acid affect the pH and H+ concentration?

• Both pH and H+ decrease
• Both pH and H+ increase.
• The pH decreases while the H+ increases.
• The pH increases while the H+ decreases.

Biological buffers function to achieve a pH range of _____________.

• 4.5-5.5
• 6.5-7.5
• 5.5-6.5
• 7.5-8.5

Which is the best example of a solution?

• blood
• milk
• paint
• seawater