Determine the type of reaction (S, D, SD, or DD) and balance the chemical equation. (Hint: Please place a coefficient of 1 in front of any formula that does not need its atoms to increase.)
Type of reaction
НІ
--
H2
+
12
Blank 1: 1
Blank 2:
Blank 3:
Blank 4:

Answer and Explanation: The types of reaction represented in the question are the following: S is Synthesis; D is Decomposition; SD is Single Displacement; and DD is Double Displacement.

The reaction showed is: HI ⇄ H₂ + I₂

This reaction's type is Decomposition, because it is a reaction in which a compund breaks down into 2 or more simpler compounds. Most of them requires energy that could be in form of heat, light or electricity.

To balance a chemical equation, remember that, according to the Conservation of Mass Law, matter can not be created or destroyed just transformed. Then, the amount of reagents that enters the reaction has to be same amount that reacts to become the products, i.e.:

For the decomposition reaction, there are 2 atoms of hydrogen and 2 atoms of iodine being produced while only 1 atom of each element enters the reaction.

The balanced reaction will be: 2HI ⇄ H₂ + I₂

A

Explanation:

Remark

One of the handiest things to know in physics is something called dimensional analysis.

Look at the answers you are given. All of them are in N/m. That means 2 things.

No conversions are necessary

You divide Newtons / meters. You don't need to worry too much about a formula.

But if need a formula, it is F = k * x and you need k

x = 3.5 m

F = 20.0 N

k = F / x

k = 20.0/3.5

k = 5.71 to 3 places.