A: Chemistry = Chemical Changes 1.5 Calculating Concentration Flashcards
What is used to determine the relative concentrations of solutions?
Qualitative properties
Observing qualitative properties can provide insights into the concentration of solutions.
What is often useful to know about a solution in science and technology?
Specific amount of solute dissolved in a solvent
Knowing the exact quantity of solute helps in various calculations and applications.
What are three common ways to express concentrations?
Percent by volume, ppm, molarity
These methods allow for different contexts and applications in communicating concentration.
What does % V/V represent?
Volume of liquid solute in total volume of solution
This is a common way to express concentration in solutions.
What does ppm stand for?
Parts per million
This unit is often used for very dilute aqueous solutions.
What does molarity express?
Amount of moles of a pure substance in total volume of solution
Molarity is a key concept in chemistry for expressing concentration.
Fill in the blank: Manufacturers of consumer products use _______ to communicate concentration.
Percent by volume
This is commonly used in product labeling.
Who uses ppm to communicate concentration levels?
Agencies that set health and safety standards
Ppm is crucial for monitoring pollutants and health safety.
True or False: Scientists and lab technicians primarily use molarity to communicate concentration.
True
Molarity is essential for chemical reactions and laboratory work.
What is the formula for calculating % V/V?
mL of solute / mL of solution x 100%
This formula helps in determining the concentration of a solute in a solution.
What is the formula for calculating ppm?
g of solute / g of solution x 10^6
This formula is particularly useful for expressing very low concentrations.
What is the formula for calculating molarity?
mol of solute / L of solution
Molarity is a standard way to express concentration in chemistry.
What is a mole?
A specific amount of a substance that consists of 6.022 x 10^23 particles
This constant is known as Avogadro’s number.
Define molar concentration.
The amount of solute, in moles, per litre of solution
Molar concentration is commonly referred to as molarity.
How many hydrogen molecules are produced from breaking down one water molecule?
Twice as many hydrogen gas molecules as oxygen gas molecules
This reflects the stoichiometry of the water molecule, H2O.
Why is the mole a useful quantity in chemistry?
It enables technologists to combine precise amounts of substances for complete conversion in chemical reactions.
Fill in the blank: The molar concentration of a solution can be calculated using the following relationship: number of moles of _______.
[solute]
This relationship is essential for determining the concentration of a solution.
True or False: Molarity is most often used to communicate concentrations within the scientific community.
True
What is the most common way to communicate concentrations in the scientific community?
Molar concentration or molarity
Molar concentration is widely used in chemistry to express the concentration of a solution.
How can the molar concentration of a solution be calculated?
C = (Number of moles of solute) / (Total volume of the solution)
This formula helps in determining the concentration of solute in a given volume of solution.
What does the molar concentration communicate?
The number of molecules or ions of solute dissolved or dissociated in a specified volume of a solution
This is crucial for understanding the properties and behavior of the solution.
Fill in the blank: The molar concentration of a solution is calculated using the formula C = _______ / V.
n
‘n’ represents the number of moles of solute.
True or False: Molar concentration is expressed in units of mol/L.
True
Molarity is defined as moles of solute per liter of solution.
What should always be included when recording measurements or doing calculations?
Units
Including units ensures clarity and precision in communication.
In Example Problem 1.11, what unit was the volume of the solution given in?
Millilitres (mL)
The volume can also be expressed in litres (L) for consistency.
What is a conversion factor?
A fraction used to convert one set of units into another
Conversion factors are essential for unit conversion in calculations.