Unit 6: Stoichiometry

Stoichiometry

100

List the steps to Stoichiometry. 

1.  Balanced equation
2.  Convert starting quantity to moles
3.  Use the mole ratio (coefficients)
4.  Convert back to desired unit

200

If 1 mole of NH₃ is added to an unlimited supply of O_2, how many moles of NO will be produced?

4 NH₃  +  5 O₂------>  4 NO  + 6 H₂O

1 mole NO

300

How many grams of Fe₂O₃ will be produced if you start with 42.84 g of Fe?

2 Fe  +  3 H₂O  ----->  Fe₂O₃  +  3 H₂

61.25 g Fe₂O₃

400

If 98.03 g of Mg(OH)₂ are decomposed, how many grams of H₂O are produced?

____ Mg(OH)₂  ----->  _____ MgO  +  ____ H₂O

30.28 g H₂O

500

2 moles of H₂ and 2 moles of N₂ are used to produce NH₃?  How many grams of NH₃ will be produced?  Which reactant is the limiting reagent?

____N₂  +  ___ H₂ ----->  ____ NH₃

56.16 g NH₃

N₂ is the limiting reagent

Percent Composition

100

What is the % Na in NaCl.

39.3%

200

What is the % composition by mass of all elements in Ca(NO₃)₂?

Ca=24.4%
N=17.1%
O=58.5%

300

How many grams of Cu are in 45 g of CuO?

35.95 g

400

In lab you use 1.5 g of Cu and produced 1.73 g of CuO.  What is the % O in your product?

13.3%

500

You dig up a 2,000 g piece of argentite, which is an ore of silver with a chemical formula of Ag₂S.  Silver is currently $.84/gram.  How much is your piece of argentite worth?  

Ag₂S = 87.1% Ag

1,741.17 g of Ag in 2,000 g of argentite at $.84/g =
$1,462,59 

Balancing Equations

100

During all chemical reactions mass, energy, and charge are ______.

A.  absorbed                   B.  formed
C.   conserved                 D.  released

C. conserved

200

Balance the following equation:

____H₂  +  ____O₂----> ___H₂O

2 H₂  +   O₂----> 2 H₂O

300

Balance the following equation:

___Cu +  ____AgNO₃ ---->  ____Ag  +  ___Cu(NO₃)₂

Cu +  2 AgNO₃ ---->  2 Ag  +  Cu(NO₃)₂

400

Balance the following equation:

__ AlBr₃  + ___ K₂SO₄ ---->  __KBr  + ___ Al₂(SO₄)₃

2 AlBr₃  + 3 K₂SO₄ ---->  6 KBr  +  Al₂(SO₄)₃

500

Balance the following equation

____C₆H₁₄  + ___ O₂ ---->  ___ CO₂ + ___ H₂O

2 C₆H₁₄  + 19 O₂ ---->  12 CO₂ + 14 H₂O

Mole Conversions

100

How many particles are in 1 mole of any substance?

6.02 x 10²³

200

How many moles of C are in 50 g of C?

4.16 moles

300

How many moles are there in 4.3 x 10²⁴ atoms of Fe?

7.14 moles

400

How many grams are in 1.3 x 10^-4 moles of (NH₄)₂SO₄?

0.0172 g

500

How many grams are in 3.4 x 10²³ molecules of AgCl?

80.94 g AgCl

This and That

100

What is the name of Al₂(SO₄)₃?

aluminum sulfate

200

In order for a chemical reaction to begin, energy must be ____.

A.  Absorbed
B.  Released
C.  Created
D.  Destroyed

A. absorbed

300

What is the chemical formula for copper (II) nitrate?

Cu(NO₃)₂

400

How many protons, neutrons, and electrons are in a Cu⁺¹ ion?

29 Protons
35 Neutrons
28 Electrons

500

What is the noble gas electron configuration for Gold, Au?

[Xe] 6s²4f¹⁴5d⁹