CHM1025C Module One Sample Test      Answers

Part C1: Compounds and Chemical Formulas (Section3.4) 

 

1.   State the Law of Definite Composition:

 

The principle that states a compound always contains the same elements in the same proportions by mass (also known as the Law of Definite Proportions) (Section 3.5)

 

2.   Define Molecule:

 

A single particle composed of nonmetal atoms (section 3.5)

 

3.   The chemical formula for vitamin B3 is:  C6H6N2O

 

In One Molecule How Many:

 

__6__ carbon atoms

 

__1__ oxygen atoms

 

__15__ total atoms

 

4.   Write the chemical formula for Vitamin B6 which has eight Carbon atoms, 11 Hydrogen atoms, one Nitrogen atom, and three Oxygen atoms:

 

C8H11NO3

 

How many total atoms are there in one Vitamin B6 molecule?

23

5.   Citric Acid (in citrus fruit) has the following chemical formula:

 

C3H4OH(COOH)3

 

In one molecule of Citric Acid, How many:

 

__6___Carbon atoms

 

__7___Oxygen Atoms

 

__8___ Hydrogen Atoms

 

__21___ total atoms