ch9 limiting reactants lab

Use my data for the methanol cannon . .. or the data we collected... or both

1. Data:

Mass of methanol bottle before ______ (80.12g )

Mass of methanol bottle after ______ (78.90g )

Mass of oxygen in cannon _______  found by mr j (0.45g everyone) 

Balanced Chemical Equation:  (methanol  is CH3OH)

___________     CH3OH                +                                  =                            +  

Find the limiting reactant, showing work:

The limiting reactant is ________________  and the excess reactant is ___________________

(The limiting reactant determines everything)

mass of carbon dioxide produced ______________   work:

mass of water vapor produced _______________  work:

mass of excess reactant remaining after reaction _______________ work:  

2.a practice methane problem: 48 grams of methane and 80g of oxygen are mixed and ignited;  

Find limiting reactant, mass of both products, and amount of excess reactant remaining after ignition; show work.

b.  practice Hydrogen problem: 12 grams of hydrogen and 80g of oxygen are mixed and ignited. 

Find limiting reactant, mass of product, and amount of limiting reactant remaining after ignition, and the amount of excess reactant remaining after ignition

3. watch  Wack-A-Pack Balloon    cold heart video  reactions   baking soda and citric acid ( hydrogen citrate) (citrate ion = C6H5O7-3 ) in presence of water, produce sodium citrate solution, liquid water, and carbon dioxide gas which inflates a valentine heart.  No water in reactants place water above arrow in the equation. 

a. Write the balanced chemical equation 

b. then calculate mass of each reactant that put into the heart package (hint; you will have to estimate the volume of the inflated heart; that would be your starting point)  

c. then calculate how much would be needed to inflate a quart or gallon  storage bag.  When Mr. Johnson returns, you may Bring a bag to school if you want to try it;  Show amounts & work to Mr. Johnson, if he approves, you may carry out the experiment.  

.Use my data if you fail to get  your own. 

4.   watch  hand warmer  hand warmer:   mass before= 21.35g  pack after reaction 23.90g 

What mass of Iron was needed to make the pack? Hint: Iron III oxide is formed in the reaction; the plastic must be removed for oxygen to get in; all other ingredients (below) are catalysts (place above above arrow) 

ACTIVATED CHARCOAL

This porous material holds the water necessary for the oxidizing reaction to occur. It's also thermally conductive, so it helps spread heat evenly. To make it, heat charcoal in the presence of an oxidizer. It expands to create millions of tiny pores between its carbon atoms, increasing the surface area to as much as 2,000 square meters per gram. A pound of activated charcoal has the same surface area as six football fields—that's a lot of crannies for storing water.

SODIUM CHLORIDE

Like in your kitchen, salt amplifies things. As a de-icer in snowy cities, salt can cause car underbellies to corrode. Here too NaCl (with an assist from H2O) is a handy catalyst that kicks the rust reaction into gear.

VERMICULITE

With a name derived from the Latin word vermiculus, little worm, this hydrated magnesium aluminum silicate expands when heated and looks like, well, worms. The result is a light, highly absorbent, chemically inert, odorless, and fire-resistant supermaterial. It's a great insulator, both here and in some building materials. Along with the activated charcoal, it helps diffuse the iron powder so the filings don't burn too quickly (and sear your skin). Herpetologists use this stuff to keep incubating reptile eggs cozy—your warm-blooded hands should be no problem..  

fill out limiting reactants form with results. Look at class results later.