E ël Gizmos
Date
Name:
Student Exploration: Stoichiometry
Directions: Follow the instructions to go through the simulation. Respond to the questions and
prompts in the orange boxes.
Vocabulary: Avogadro's number, balanced equation, cancel, coefficient, conversion factor, dimensional
analysis, molar mass, mole, molecular mass, stoichiometry
Prior knowledge Questions (Do these BEFORE using the Gizmo.)
1. A 250 mL glass of orange juice contains 22 grams of sugar. How much sugar is in a two-liter 2,000 ml)
bottle of orange juice?
2. It requires two sticks of butter to make a batch of 20 cookies. How much butter will it take to make 150
cookies?
Now equation
Pes) SCO
2 CO,
Gizmo Warm-up
Just as a cook follows a recipe to decide how much of each
Ingredient to add, a chemist uses stoichiometry to determine
the amounts of substances involved in chemical reactions. The
Stoichiometry Gizmo allows you to try your hand at figuring out
the amounts of reactants and products that take part in a
chemical reaction
To begin, check that this equation is shown:
New question
How many moes of carbon monoxid (CO)
Fe
70,0, + 3C02Fe +300,
1. Look at the coefficients (such as the "3" in 3CO) in front of each substance in the equation. The

answer is: naturally occurring solid, inorganic compound or element is mineral.

minerals usually have crystalline form, that means than crystal constituents (atoms, molecules or ions) are arranged in a highly ordered microscopic structure, forming a crystal lattice that extends in all directions.

for example magnetite is a mineral of iron oxide (fe₂o₃).

calcite is a carbonate mineral and the most stable polymorph of calcium carbonate (caco₃).

dolomite is an   carbonate mineral composed of calcium magnesium carbonate (camg(co₃)₂).

the correct answer is b. a strong acid completely dissociates to its ions when dissolved in water. completely dissociates to and ions. a is incorrect because does not fully ionize to and ions and some remain as the compound . c and d are incorrect because, and do not fall into the category of bronsted lowry acids. a bronsted lowry acid is a proton donor and since both molecules do not have a proton to donate they are not bronsted lowry acids. likewise,   if we use the lewis acid definition, they cannot be acids. a lewis acid is an electron pair acceptor. both and have a complete octet so can not accept any electrons which disqualifies them as acids.

answer : third trial had the contaminated sample and the correct value for dhrxn should be 1000 kj/mol

explanation :

let us write down the given equations

equation 1 :

equation 2 :

equation 3 :

let us use hess's law to find out which 2 equations can be added to get the third equation.

let us reverse equation 2 and multiply it by 2. the new equation that we get is,

equation 4 :

let us add equation 1 & 4

the above equation is similar to equation 3 but has different value for dhrxn.

therefore third trial had the contaminated sample and the correct value for dhrxn should be 1000 kj/mol