Question

1. choose the best answer.

another name for combination reaction is a ______ reaction.
○ synthesis
○ decomposition
○ replacement
○ compound

1. choose the best answer.

which equation shows that a catalyst has been added?
○ $2\ce{nacl} \stackrel{\delta}{\
ightarrow} 2\ce{na} + \ce{cl2}$
○ $\ce{n2o} \stackrel{\ce{co}}{\
ightarrow} \ce{n2} + \ce{o2}$
○ $2\ce{mg} + \ce{o2} \
ightarrow 2\ce{mgo}$
○ $2\ce{li} + \ce{br2} \leftrightarrow 2\ce{libr} + \text{energy}$

Explanation:

Question 7

A combination reaction is when two or more substances combine to form a single product. A synthesis reaction is defined as a reaction where substances combine to form a more complex substance, so combination and synthesis reactions are the same. Decomposition is the opposite (breaking down), replacement involves replacing elements, and compound is a substance type, not a reaction type.

A catalyst is written above the reaction arrow. In the options, \( \ce{N2O \xrightarrow{CO} N2 + O2} \) has \( \ce{CO} \) above the arrow, indicating it's a catalyst. The other options have heat (\( \Delta \)), no catalyst indicator, or a reversible reaction with energy, not a catalyst.

Answer:

A. synthesis

Question 8