Chemical Reactions (quiz 1)

When a chemical reactions occurs... [select all that apply]

• Atoms are re-arranged

• It forms bubbles all the time

• New substances are formed

• It gets hot

A chemical reaction is....

• a process that never creates a new substance

• a process that creates double the amount of molecules present in the reactants.

• a process that leads to the changing of one set of chemicals into another

• a process that destroys double the amount of molecules present in the reactants.

Which of the following is NOT a way to determine whether a chemical reaction took place?

• change in smell

• change in color

• change in temperature

• change in orientation

Which are the REACTANTS?

• Na and Cl₂

• Na only

• Cl₂ only

• NaCl

Which are the PRODUCTS?

• Na and Cl₂

• Na only

• Cl₂ only

• NaCl

4Na + 2Cl₂ ---> 4NaCl

How many Sodium (Na) atoms are there in the products?

• 1

• 2

• 3

• 4

4Na + 2Cl₂ ---> 4NaCl

How many Chlorine (Cl) atoms are there in the reactants?

• 1

• 2

• 3

• 4

Mass ___________ be created or destroyed.

• can

• cannot

If a reaction absorbs heat is said to be _________________.

• Exothermic

• Endothermic

If a reaction releases heat is said to be _________________.

• Exothermic

• Endothermic