Chapter 4: Quantities of Reactants and Products
... and 14 O) in the products and reactants. The law of conservation of mass says that masses of the reactants
must add up to the masses of the products, 284.16 g. This looks right.
12. Define the problem: Given the balanced equation for a reaction, identify the stoichiometric coefficients in
this equat ...
CHAPTER 3 STOICHIOMETRY
... Solution: Let's first calculate the number of N atoms in 1.68 10 g of urea. First, we must convert grams
of urea to number of molecules of urea. This calculation is similar to Problem 3.26. The molecular formula
of urea shows there are two N atoms in one urea molecule, which will allow us to conve ...
Sample Chapter 3
... activity from a tropical plant: what is its formula, and what quantity of metabolic
products will establish a safe dosage level? Thousands of biologically active compounds have been found in plants and many are used in modern medicines. For
example, in 1963, the U.S. Food and Drug Administration (FD ...
Topic 1 Quantitative Chemistry Answers - slider-dpchemistry-11
... atomic masses of all the atoms that comprise the molecule. As for relative atomic mass there are no units. For
example, the Mr of water H2O is (H: 2 x 1.01) + (O: 16.00) = 18.02.
c) molar mass
The collective name for properties that are expressed with units of mass per mole is known as molar mass.
... factor to clear the fractional coefficients
4. Verify that the equation is balanced and the
coefficients are the smallest whole numbers
5. Specify physical states
... • Amorphous metal is so tightly packed that this does not occur
because the atoms of different sizes and randomly pack
Dr. S. M. Condren
2 - OnCourse
... This is an empirical formula. The true chemical
formula could be a whole number multiple of the
empirical formula. The chemical formula of the
substance analyzed could be C8H18 or any other
whole number multiple.
Molar mass of empirical formula
4 moles C x 12.01 g/mol C = 48.04 g C
Calculations and the Chemical Equation
... Relating Avogadro's number to molar mass: calculation of the mass of Avogadro's
number of sodium atoms
Converting moles to atoms.
Converting atoms to moles.
Converting moles of a substance to mass in grams.
Converting kilograms to moles.
Converting grams to number of atoms.
Calculating formula weigh ...
Alternative Coverage of moles, molarity, and Chemical Calculations
... To aid in chemical calculations, chemists use a unit called a mole. The quantity of a substance whose mass in grams is numerically equal to the formula mass of the
substance is called a mole. The abbreviation for mole is mol and is often used
whenever a specific quantity of moles is written, for exa ...
Chapter 3 HWsolutions (from Handout)
... Strategy: Looking at the balanced equation, how do we compare the amounts of
Cl 2 and SiCl4? We can
compare them based on the mole ratio from the balanced equation.
Solution: Because the balanced equation is given in the problem, the mole
ratio between Cl 2 and SiCl4 is
known: 2 moles Cl2 1 mole S ...
Chapter 6 Quantities in Chemical Reactions
... Now that we have introduced the mole and practiced using it as a conversion factor,
we ask the obvious question: why is the mole that particular number of things? Why
is it 6.022 × 1023 and not 1 × 1023 or even 1 × 1020?
The number in a mole, Avogadro’s number, is related to the relative sizes of th ...
Ch. 12 Stoichiometry
... How many molecules of NH3 are needed to produce
2.34 x 1022 molecules of N2F4?
How many grams of HF are produced from a reaction of
4.56 x 1023 molecules of F2 with excess NH3?
What volume of HF, at STP, can be produced from 345g
How many molecules of N2F4 can be produce from 45.6L
of F2 , a ...
... Ex: Calculate the number of grams of oxygen
required to react exactly with 4.30 mol of
propane, C3H8, in the reaction by the
following balanced equation:
C3H8(g) + 5O2(g) 3CO2(g) + 4H2O(g)
5 mol O2
32.0 g O2
4.30 mol C3H8 x _____________
1 mol C3H8
1 mol O2
... Step 2 is to identify the limiting reactant.
This requires a balanced chemical
equation so that the mole ratio of the
reacting substances can be identified.
2 Na + 2 H2O → H2 + 2 NaOH
For every 2 mol of Na that react, 2 mol of
H2O react, a 2:2 or 1:1 ratio. Thus, the
1.04 mol Na will be the limiting ...
Unit 3 2 Basic Mole Conversions and Mole Maps
... This connects to the Law of the Conservation of Matter (MR #1) … since
the process is concerned solely with the conversion of one measurement to a
different frame of reference, then the process is really concerned with ensuring
that whatever you “put into the reaction”, you somehow, “get out” with p ...
... It is the volume of a gas that a mole of a gas occupies at a
pressure of one atmosphere (101 kPa) and a temperature
of 0.00°C. Under these conditions (STP), the volume of
one mole is 22.3 L.
Mead Chemistry Lap 11: Stoichiometry Chapter 12 12.1 Balanced
... Mead Chemistry
Lap 11: Stoichiometry
12.1 Balanced Chemical Equations
A. Balanced equations
• Used to find how much reactant is needed
• Used to predict how much product will be made
• You can use amount of one substance to find the amounts of the other substances
• Quantity usually in mo ...
... us the mole ratio.
• It takes 1 mole of ethanol to react with 3
moles of oxygen. This produces 2 moles of
carbon dioxide and 3 moles of water.
• The mole ratio will act as our conversion
... 1. Safety goggles must be worn at all times during a lab. This rule must be followed not matter what
you are doing during the lab period.
2. Contact lenses are not allowed. Even when worn under safety goggles, since fumes from the
chemicals can get under them and cause serious injuries or blindness. ...
... • If 3.84 moles of C2H2 are burned, how
many moles of O2 are needed?(9.6 mol)
•How many moles of C2H2 are needed to
produce 8.95 mole of H2O? (8.95 mol)
•If 2.47 moles of C2H2 are burned, how
many moles of CO2 are formed? (4.94 mol)
mass mass calc
... In a particular lab set up, 50.0 g of oxygen gas are available for the combustion of 25.0 g of carbon..
a) Calculate the number of moles of oxygen gas and carbon solid that are each available to react.
b) Calculate the number of moles of oxygen gas that will actually be needed to react with all of
Chem 11 Stoichiometry (mol-mol) Using the formulas we have
... reactant. Using other mole-quantity relationships, we can introduce mass, volume, and
particles into our calculations (this is what we will be getting to in the next few classes).
How many moles of ammonia are produced when 0.60 mol of nitrogen reacts with
We will wo ...
... The equation in terms of molecules
The equation in terms of moles
In engineering and science, dimensional analysis is the analysis of the relationships between different physical quantities by identifying their fundamental dimensions (such as length, mass, time, and electric charge) and units of measure (such as miles vs. kilometers, or pounds vs. kilograms vs. grams) and tracking these dimensions as calculations or comparisons are performed. Converting from one dimensional unit to another is often somewhat complex. Dimensional analysis, or more specifically the factor-label method, also known as the unit-factor method, is a widely used technique for such conversions using the rules of algebra.The concept of physical dimension was introduced by Joseph Fourier in 1822. Physical quantities that are commensurable have the same dimension; if they have different dimensions, they are incommensurable. For example, it is meaningless to ask whether a kilogram is less, the same, or more than an hour.Any physically meaningful equation (and likewise any inequality and inequation) will have the same dimensions on the left and right sides, a property known as ""dimensional homogeneity"". Checking this is a common application of dimensional analysis. Dimensional analysis is also routinely used as a check on the plausibility of derived equations and computations. It is generally used to categorize types of physical quantities and units based on their relationship to or dependence on other units.