The acidity of a solution is typically assessed experimentally by measurement of its pH. The pOH of a solution is not usually measured, as it is easily calculated from an experimentally determined pH value. The pH of a solution can be directly measured using a pH meter (
[link] ).
(a) A research-grade pH meter used in a laboratory can have a resolution of 0.001 pH units, an accuracy of ± 0.002 pH units, and may cost in excess of $1000. (b) A portable pH meter has lower resolution (0.01 pH units), lower accuracy (± 0.2 pH units), and a far lower price tag. (credit b: modification of work by Jacopo Werther)
The pH of a solution may also be visually estimated using colored indicators (
[link] ).
(a) A universal indicator assumes a different color in solutions of different pH values. Thus, it can be added to a solution to determine the pH of the solution. The eight vials each contain a universal indicator and 0.1-
M solutions of progressively weaker acids: HCl (pH = l), CH
3 CO
2 H (pH = 3), and NH
4 Cl (pH = 5), deionized water, a neutral substance (pH = 7); and 0.1-
M solutions of the progressively stronger bases: KCl (pH = 7), aniline, C
6 H
5 NH
2 (pH = 9), NH
3 (pH = 11), and NaOH (pH = 13). (b) pH paper contains a mixture of indicators that give different colors in solutions of differing pH values. (credit: modification of work by Sahar Atwa)
Key concepts and summary
The concentration of hydronium ion in a solution of an acid in water is greater than 1.0
10
−7M at 25 °C. The concentration of hydroxide ion in a solution of a base in water is greater than 1.0
10
−7M at 25 °C. The concentration of
in a solution can be expressed as the pH of the solution; pH = −log
The concentration of OH
− can be expressed as the pOH of the solution: pOH = −log[OH
− ]. In pure water, pH = 7.00 and pOH = 7.00
Key equations
pOH = −log[OH
− ]
[H
3 O
+ ] = 10
−pH
[OH
− ] = 10
−pOH
pH + pOH = p
Kw = 14.00 at 25 °C
Chemistry end of chapter exercises
Explain why a sample of pure water at 40 °C is neutral even though [H
3 O
+ ] = 1.7
10
−7M .
Kw is 2.9
10
−14 at 40 °C.
In a neutral solution [H
3 O
+ ] = [OH
− ]. At 40 °C,
[H
3 O
+ ] = [OH
− ] = (2.910
−14 )
1/2 = 1.7
10
−7 .
The hydronium ion concentration in a sample of rainwater is found to be 1.7
10
−6M at 25 °C. What is the concentration of hydroxide ions in the rainwater?
In economics, a perfect market refers to a theoretical construct where all participants have perfect information, goods are homogenous, there are no barriers to entry or exit, and prices are determined solely by supply and demand. It's an idealized model used for analysis,
When MP₁ becomes negative, TP start to decline.
Extuples Suppose that the short-run production function of certain cut-flower firm is given by: Q=4KL-0.6K2 - 0.112 •
Where is quantity of cut flower produced, I is labour input and K is fixed capital input (K-5). Determine the average product of lab
Kelo
Extuples Suppose that the short-run production function of certain cut-flower firm is given by: Q=4KL-0.6K2 - 0.112 •
Where is quantity of cut flower produced, I is labour input and K is fixed capital input (K-5). Determine the average product of labour (APL) and marginal product of labour (MPL)
Quantity demanded refers to the specific amount of a good or service that consumers are willing and able to purchase at a give price and within a specific time period. Demand, on the other hand, is a broader concept that encompasses the entire relationship between price and quantity demanded
Ezea
ok
Shukri
how do you save a country economic situation when it's falling apart
Economic growth as an increase in the production and consumption of goods and services within an economy.but
Economic development as a broader concept that encompasses not only economic growth but also social & human well being.
Shukri
production function means
Jabir
What do you think is more important to focus on when considering inequality ?
sir...I just want to ask one question... Define the term contract curve? if you are free please help me to find this answer 🙏
Asui
it is a curve that we get after connecting the pareto optimal combinations of two consumers after their mutually beneficial trade offs
Awais
thank you so much 👍 sir
Asui
In economics, the contract curve refers to the set of points in an Edgeworth box diagram where both parties involved in a trade cannot be made better off without making one of them worse off. It represents the Pareto efficient allocations of goods between two individuals or entities, where neither p
Cornelius
In economics, the contract curve refers to the set of points in an Edgeworth box diagram where both parties involved in a trade cannot be made better off without making one of them worse off. It represents the Pareto efficient allocations of goods between two individuals or entities,
Cornelius
Suppose a consumer consuming two commodities X and Y has
The following utility function u=X0.4 Y0.6. If the price of the X and Y are 2 and 3 respectively and income Constraint is birr 50.
A,Calculate quantities of x and y which maximize utility.
B,Calculate value of Lagrange multiplier.
C,Calculate quantities of X and Y consumed with a given price.
D,alculate optimum level of output .
the market for lemon has 10 potential consumers, each having an individual demand curve p=101-10Qi, where p is price in dollar's per cup and Qi is the number of cups demanded per week by the i th consumer.Find the market demand curve using algebra. Draw an individual demand curve and the market dema
suppose the production function is given by ( L, K)=L¼K¾.assuming capital is fixed find APL and MPL. consider the following short run production function:Q=6L²-0.4L³ a) find the value of L that maximizes output b)find the value of L that maximizes marginal product
