Module 9: Laboratory Procedures in Determining Concentration of Solutions Flashcards
Which of the following statements is NOT correct?
A. Solution stoichiometry pertains to aspects of reactions in aqueous solution.
B. Dilution is preparing less concentrated solution from a concentrated one.
C. Quantitative analysis refers to the descriptive concentration of a substance in a sample.
D. Molarity is commonly used to express concentration in solution.
C. Quantitative analysis refers to the descriptive concentration of a substance in a sample.
What is the difference between the endpoint and equivalence point in a titration?
A. The endpoint is when the pH is exactly 7
B. The equivalence point is when the pH is exactly 7
C. The endpoint and the equivalence point are the same thing.
D. The endpoint is always greater than the equivalence point
B. The equivalence point is when the pH is exactly 7
Hydrogen and chlorine react according to the equation:
H2 (g) + Cl2(g) → 2HCl(g)
When this reaction is complete the vessel will contain:
A. 5 mole of HCl
B. 6 mole of HCl and 1 mole of Cl2
C. 4 mole of HCl and 1 mole of Cl2 D. 4 mole of HCl and mole of H2
D. 4 mole of HCl and mole of H2
Water is added to 25.0 mL of 0.866 M KNO3 solution until the volume of the solution is exactly 500 mL. What is the concentration of the final solution?
A. 0. 0433 M
B. 0. 0403 M
C. 0.3822 g
D. 0.3922 g
A. 0. 0433 M
How many grams of of KHP (Potassium Hydrogen Phthalate) are needed to neutralize 18.64 mL of a 0.1004 M NaOH solution?
A. 0. 0382 g
B. 0. 40 g
C. 0.3822 g
D. 0.3922 g
C. 0.3822 g
The amount of a substance that contains 6.02 x 10 23
particles.
Mole
An example of solid dissolved in solids.
Alloys
A ratio expressing the number of moles of solute in one liter of solution.
Molarity
A ratio expressing the number of moles of solute in one
kilogram of solvent.
Molality
A ratio of moles of solute in a solution to the total number
of moles of both solvent and solute.
Mole fraction
A measurement of the amount of solute that is dissolved
in a given amount of solvent.
Concentration of Solution
Solution concentration in parts of solute per 100 parts of
solution.
Percent
To study stoichiometry you must know how much of the 1. ________ are present in a solution and also how to control the amounts of reactants to be used to come up a reaction in aqueous solution. ( reactants, product)
reactants
2.______________ analysis is the determination of amount or concentration of a substance in a sample. ( qualitative, quantitative )
quantitative
- _______ considered as highly accurate technique, since the mass of a sample can be measured accurately. (gravimetric analysis, titration)
gravimetric analysis
4.This procedure is usually applied to ________ compounds. (ionic, covalent)
ionic
- A typical titration analysis involves the use of a ________(buret, flask)
buret
. In preparing solution sample, a known amount of solid solute is transferred to a ________, then water is added to it using a funnel.
A. Volumetric flask
B. Graduated cylinder
C. Erlenmeyer flask
D. Beaker
A. Volumetric flask
Which of the following set of apparatuses are used in titration process?
A. buret, iron ring and stand, volumetric flask, beaker
B. iron stand, volumetric flask , Erlenmeyer flask
C. buret, Erlenmeyer flask, buret clamp, iron stand
D. iron stand , utility clamp, volumetric flask, buret
C. buret, Erlenmeyer flask, buret clamp, iron stand
The end point in a titration of a 50.00-mL sample of aqueous HCl was reached
by addition of 35.23 mL of 0.250 M NaOH titrant. The titration reaction is:
What is the molarity of the HCl?
A. 0.176 M HCl
B. 1.76 M HCl
C. 0.0176 M HCl
D. 17.6 M HCl
A. 0.176 M HCl
A sample of 0.6760 g of an unknown compound containing barium ions ( Ba2+) is dissolved in water and treated with an excess of Na2 SO4 . If the masses of the BaSO4 precipitate formed is 0.4105 g, what is the percent by mass of Ba in the original unknown compound? A. 37.52 %
B. 35.72 %
C. 32.57%
D. 37.72 %
B. 35.72 %
What is the concentration ( in molarity ) of a NaOH solution if 25.0 mL of the solution are needed to neutralize 17.4 ml of a 0.312 M HCl solution?
A. 0.217 M
B. 0.127 M
C. 0.271 M
D. 0.712 M
A. 0.217 M
