why must a ph meter be calibrated by using a solution with a known ph value

Answers

Answer 1

Answer:

A pH calibration is the process of adjusting your pH meter by measuring solutions of a known pH value. This is because the characteristics of your electrode will change over time and this needs to be compensated for. A calibration does this by matching your pH meter to the current characteristics of your pH sensor.

Explanation:


Related Questions

What is the volume in mL of 1 Kg of gold? The density of gold is 19.3 g/mL.

Answers

Answer:

Volume occupied is approx.  

38 ⋅ ML

Explanation:

Density  ρ = Mass  Volume  And thus  Volume  = Mass  ρ = 1.592 ⋅ l b × 454 ⋅ g ⋅ l b − 1 19.3 ⋅ g ⋅ m L − 1   =   ? ? ⋅ m L

a vessel contains 66 g co2 and 16 g o2 at a pressure of 10.0 atm. what is the partial pressure of co2?

Answers

This question is providing the masses of carbon dioxide and oxygen gases at 10.0 atm as 66 g and 16 g respectively, and is asking for the partial pressure of the former which turns out to be 7.50 atm after doing the math.

Thus, we can start solving this problem with the Dalton's law approach, in order to make a relationship for the total pressure, partial pressure and mole fraction, which means we must first determine the mole fraction of carbon dioxide gas in the mixture as shown below:

[tex]x_{CO_2}=\frac{n_{CO_2}}{n_{CO_2}+n_{O_2}}[/tex]

Next, we calculate the moles of both gases by dividing the grams over the molar masses:

[tex]n_{CO_2}=\frac{66g}{44.01g/mol} =1.50mol\\\\n_{O_2}=\frac{16g}{32g/mol} =0.5mol[/tex]

Then, the mole fraction of carbon dioxide as the required one by plugging in the previously calculated moles:

[tex]x_{CO_2}=\frac{1.5}{1.5+0.5}=0.75[/tex]

Finally, we use the definition of the Dalton's law to calculate the partial pressure of carbon dioxide gas in the binary mixture:

[tex]P_{CO_2}=x_{CO_2}P\\\\P_{CO_2}=0.75*10.0atm\\\\P_{CO_2}=7.50 atm[/tex]

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what is the chemical formula for Salt and hydrogen gas?

Answers

Salt: NaCl
Hydrogen gas: H2

Write out a correctly formatted hypothesis that describes how the amount of hydrogen gas produced with be affected by the concentration of acid.

Answers

When creating mixture the amount of hydrogen gas is directly related to the concentration of the acid mixture, the higher the concentration level The more hydrogen gas would be produced.

To solve such this we must know the concept of acid and base reaction. Therefore, the concentration of acid decides the concentration of hydrogen gas evolved.

What is chemical reaction?

Chemical reaction is a process in which two or more than two molecules collide in right orientation and energy to form a new chemical compound. The mass of the overall reaction should be conserved. There are so many types of chemical reaction reaction like combination reaction, double displacement reaction.

When creating mixture the amount of hydrogen gas is directly related to the concentration of the acid mixture, the higher the concentration level The more hydrogen gas would be produced.

Therefore, the concentration of acid decides the concentration of hydrogen gas evolved.

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What can form along faults when pushed together or pulled apart?
O Mountains
O Volcanoes
O Both

Answers

Answer:

Both

Explanation:

if you pull a mountain a part that would be great consequences and if a volcano breaks there will be fire .

A Mountain is formed when two faults push together and a volcano is formed when two faults are pushed together and there is a pocket of air

Why are metals sometimes added to gold?

to make it softer and more malleable
to improve the value of gold
to raise its melting point
to make gold stronger and more durable

Answers

To make it softer and more malleable

why is xenon monatomic but bromine is diatomic

Answers

B 3-4 is the auto
If it’s needs

If 12.7 grams of hydrogen reacted with an unknown amount of oxygen, how many grams of water would be produced? (Write a balanced equation and show your work under the equation)

Answers

Answer:

    2H2    +   1 O2   ------>    2H2O

m = 12.7g                              m = ?

Get the number of moles for Hydrogen gas (H2) by dividing the mass by the molar mass (1.01g/mol as listed in the periodic table for its atomic mass)

12.7/1.01 = 12.57 mol of H2

Now use the mole to mole ratio of Hydrogen gas (H2) and water (H2O).

From the balanced equation, we can see that 2 mol of H2 gives us 2 mol of H2O. Since both of the ratios are equal (2:2), the moles we have for hydrogen gas is the same as the moles we get for water.

12.57 mol of H2O

Now that we have the amount of mol for H2O produced in this reaction, we can convert it to grams by multiplying the moles by the molar mass.

Molar mass of H2O = (1.01 x 2) + (16) = 18.02g/mol

12.57 x 18.02 = 226.5g (rounded)

Therefore 226.5g of water will be produced in this reaction

According to law of conservation of mass and stoichiometry, 114.3 g of water are produced if 12.7 grams of hydrogen reacted with an unknown amount of oxygen.

What is law of conservation of mass?

According to law of conservation of mass, it is evident that mass is neither created nor destroyed rather it is restored at the end of a chemical reaction .

Law of conservation of mass and energy are related as mass and energy are directly proportional which is indicated by the equation E=mc².Concept of conservation of mass is widely used in field of chemistry, fluid dynamics.

2 H₂ + O₂[tex]\rightarrow[/tex] 2 H₂O,according to this equation,4 g hydrogen reacts with 32 g oxygen to give 36 g water, thus 12.7 g of hydrogen will produce 12.7×36/4=114.3 g water and hence for this amount of water to be formed  12.7 g of hydrogen reacts with 101.6 g of oxygen which is obtained as 114.3-12.7=101.6 g

Thus, 114.3 g of water is produced.

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State charles's law. If a balloon occupies 885 cm3 volume at 20°C and 794 cm3 at - 10°C , prove that this is according to charles's law.

Answers

find the distance between

the following points:

a) AC0₂0) and B(5, 2)

If substances B and C are both in the gas phase and are at the same energy level, which of the two substances will need to have more energy transferred out in order to change to the liquid phase? Substance B or Substance C? Explain your answer below.
For Science

Answers

Answer:

Substances can change phase—often because of a temperature change. At low temperatures, most substances are solid; as the temperature increases, they become liquid; at higher temperatures still, they become gaseous.

The process of a solid becoming a liquid is called melting. (an older term that you may see sometimes is fusion). The opposite process, a liquid becoming a solid, is called solidification. For any pure substance, the temperature at which melting occurs—known as the melting point—is a characteristic of that substance. It requires energy for a solid to melt into a liquid. Every pure substance has a certain amount of energy it needs to change from a solid to a liquid. This amount is called the enthalpy of fusion (or heat of fusion) of the substance, represented as ΔHfus. Some ΔHfus values are listed in Table 10.2 “Enthalpies of Fusion for Various Substances”; it is assumed that these values are for the melting point of the substance. Note that the unit of ΔHfus is kilojoules per mole, so we need to know the quantity of material to know how much energy is involved. The ΔHfus is always tabulated as a positive number. However, it can be used for both the melting and the solidification processes as long as you keep in mind that melting is always endothermic (so ΔH will be positive), while solidification is always exothermic (so ΔH will be negative).

A student makes an aqueous solution of sodium hydroxide. Which statement correctly identifies the two ions present in the solute of this mixture?

The sodium ion is negative, and the hydroxide ion is positive.

The sodium ion is positive, and the hydroxide ion is positive.

The sodium ion is positive, and the hydroxide ion is negative.

The sodium ion is neutral, and the hydroxide ion is neutral

Answers

The two ions present in the solution are:

1. Sodium ion, Na⁺

2. Hydroxide ion, OH¯

The correct answer to the question is the 3rd option. The sodium ion is positive, and the hydroxide ion is negative.

Ions are atoms or group of atoms which possess an electric charge.

Aqueous Sodium hydroxide, NaOH contains sodium ion and hydroxide ion.

The sodium ion is positive while the hydroxide ion is negative as illustrated below:

NaOH(aq) —> Na⁺(aq) + OH¯(aq)

From the illustration above, we can conclude that the correct answer to the question is the 3rd option. The sodium ion is positive, and the hydroxide ion is negative.

Please see attached photo for further details

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A force is a push or a pull under the right circumstances anything can exert a force push a notebook or some other object so that it slides across a table or desktop what force causes the notebook to start moving what force causes the notebook to stop moving?

Answers

Answer:

the force that you applied caused the notebook to move.the force applied on the notebook by the table causes it to stop moving. this is because after sometime the book uses up the force and later the force you applied is less than that of the force by the table.

pls help me out!! perform the mathematical operation and report to the appropriate number of significant figures 0.00325136-1.76527

Answers

Answer:

-1.76202

Explanation: Because the operation is subtraction, you would count the number of digits after the decimal point. Then you would perform the operation and round your answer to the SMALLER number of digits after the decimal point.

What does an atom's period tell us?

Answers

Answer:

A horizontal row in the periodic table, which signifies the totoal number of electron shells in an element's atom.

Explanation:

Hope this helpss)):

the sun`s blank is the layer that emits visible light

Answers

Answer: photosphere.

Explanation:

The part of the Sun commonly called its surface is the photosphere. The word photosphere means "light sphere" – which is apt because this is the layer that emits the most visible light. It’s what we see from Earth with our eyes.

What is the mass of 3.2 L of water in centigrams?

Answers

The mass of 3.2 liters of water in centigrams is 3200

The overall shape of a plant cell is most directly related to which of its parts?

Answers

Cell wall is the answer

Cell wall is a unique structure found in some organisms.

Answer: Cell wall

Explanation: Cell wall is a unique structure found only in some specific organisms like plants, bacteria, fungi etc. The cell wall in plants is predominantly made up of a polysaccharide called CELLULOSE. This carbohydrate confers upon the cell "rigidity".

The cell wall is an additive material including the cell membrane that coats the external part of the cell of plants, hence, it gives plant cells their characteristic shape. The cell wall contributes to the overall flexible but rigid shape of the plant cell, protecting the cell against physical or chemical stresses.

HELP WAAAAAAAAAAAAAAA

Answers

Answer:

5. 0.02 seconds

6. (a) 0.0167 seconds

(b) Period in Lebanon is 0.02 seconds and in the U.S 0.0167 seconds. That means that the U.S. has the faster period.

Explanation:

What are electron Subshells?

Answers

Answer:

a subshell is a subdivision of electron shells that are separated by electron orbitals.

Explanation:

(subshells are labeled s,p,d, and f in an electron configuration)

1. If the surface area of liquid is large then evaporation will be
A. small
B. large
C. moderate
D. slow

Answers

Question:-

1. If the surface area of liquid is large then evaporation will be

A. small

B. large

C. moderate

D. slow

Answer:-

B. Large

Explanation:-

Evaporation increases with increasing surface area. This is because the greater the surface area (exposed to the air), the more molecules escape into the air.

More surface area = Higher rate of evaporation.

 Write the chemical compounds and names for the following ionic compounds. Magnesium and phosphorus 

Answers

Answer:

Magnesium is Mg.

Phosphorus is P.

Why is water so susceptible to pollution?(1 point)

It's a universal solvent.

It occurs naturally as a solid, liquid, and gas.

It can be found underground.

Only 3% of Earth's water is freshwater.

Answers

A. It’s known as the “universal solvent”

what is the strongest interparticle force in a sample of so2?

Answers

Answer:

The strongest intermolecular force in sulfur dioxide is dipole-dipole forces.

Explanation:

The interparticle force in [tex]SO_{2}[/tex] (sulfur dioxide) is the dipole-dipole interaction.

What is  dipole-dipole interaction?

Dipole-dipole interaction is a type of intermolecular force that occurs between polar molecules. Polar molecules have a permanent dipole moment, which means they have a partial positive charge on one end and a partial negative charge on the other end. This creates an electrostatic attraction between the partial charges of neighboring molecules. The stronger the dipole moment of a molecule, the stronger its dipole-dipole interaction will be with other polar molecules.

Dipole-dipole interactions are responsible for a variety of physical properties of substances, including their boiling and melting points. Substances with strong dipole-dipole interactions tend to have higher boiling and melting points than substances with weaker interactions. In addition, the strength of dipole-dipole interactions can affect solubility, as polar substances tend to dissolve better in other polar substances due to their ability to form dipole-dipole interactions.

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7) Element Families on the Periodic Table have similar _____________________. There are ________ Families.

8) Alkali Metals are good conductors of _____________________________ and ________________________________.

9) There are a total of _________ elements that are grouped as Transition Metals.

10) As opposed to metals, non-metals can be very __________________________. They have no metallic ____________

and do not reflect ______________________.

11) All Lanthanide Series elements occur naturally except for ___________________________________.

12) All Actinide Series elements are ___________________________ and most are _____________________

Answers

The periodic table is composed of metals and nonmetals arranged in groups and periods.

The periodic table is an arrangement of elements in groups and periods based on their properties. The properties of elements repeat at regular intervals hence the term, "periodic".

The answers to the questions are;

7)  Element Families on the Periodic Table have similar properties. There are 18 families.

8) Alkali Metals are good conductors of heat and electricity.

9) There are a total of 38 elements that are grouped as Transition Metals.

10)  As opposed to metals, non-metals can be very opaque. They have no metallic luster and do not reflect light.

11)  All Lanthanide Series elements occur naturally except for promethium.

12)  All Actinide Series elements are radioactive and most are synthetic.

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which of the following molecular compounds does NOT need the usage of prefix for the first element
SO2
S2O3
N2S
N2S3

Answers

Answer:

SO2

Explanation:

that's my answer

Sana mKatolong

giving brainly if correct and explained​

Answers

Answer:

D.

Explanation:

A concentrated solution is one that has a lot of solute (the substance being dissolved) in the solvent (the substance doing the dissolving). When a solution is concentrated, it means it has a high ratio of solute to solvent, so the answer is D.

Hope this helps.

In Natural selection, who/what makes the decision about which traits are desirable and get passed to future generations?

In Artificial selection, who/what makes the decision about which traits are desirable and get passed to future generations?

please help me with these two questions complete sentences please thank you! This is for 50 points and BRAINLIEST.

Answers

Answer:

Artificial selection, also called "selective breeding” is where humans select for desirable traits in agricultural products or animals, rather than leaving the species.

in 1-2 sentences explain how the shorelines can affect weather.

Answers

Answer: Global warming causes sea-level rise as oceans expand, and makes storm patterns more energetic. Consequently it will affect most of the world's coastlines through inundation and increased erosion.

Explanation:

As you go down group one of the periodic table, the reactions become and more

Answers

Answer:

vigorous

Explanation:

As you go down group one of the periodic table, the reactions become and more vigorous.

Please help to complete this

Answers

you didnt put a question
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