Answer:
Group C
Explanation:
Precision is how close the values are to each other
When selecting a photometric technique that is more sensitive to a low concentration of analyte, a laboratory director compares absorbance measuring devices against those that measure fluorescence intensity. Which technique is considered more sensitive in its measurements and why
When selecting a photometric technique that is more sensitive to a low concentration of analyte, a laboratory director compares absorbance measuring devices against those that measure fluorescence intensity. Fluorescence spectroscopy is considered more sensitive in its measurements.
Spectro-fluorometer works on the above mentioned principle...
It uses a beam of light to excite the electrons from the given material which cause the emission of light from that matter.The emitted light is then brought towards a filter and onto a detector for measurement and identification of the changes in molecules of a sample material.Fluorometry is sensitive technique because light of particular wavelength is required as electrons are getting excited from ground state to emit the light and shows particular results which helps to know the sample material.Learn more about spectroscopy here..
https://brainly.com/question/27218986
#SPJ4
Temperature (°C)
At 80 °C, 100 g of potassium dichromate is added to 200 g of water. Which of the
following best describes this solution?
A The solution is saturated, more solute can be dissolved.
B The solution is saturated, no more solute can be dissolved.
C The solution is unsaturated, no more solute can be dissolved.
DThe solution is unsaturated, more solute can be dissolved.
In this experiment you used an excess of the BaCl2 solution. How would your results be affected if you did not use an excess of the BaCl2 solution? Would this error cause your calculation of the mass percent of sulfate in the unknown to be too high or too low? Explain.
if we did not use an excess of the BaCl2 solution it would decrease the mass percentage of sulfate in the unknown sample.
The net precipitation equation would be.
Ba2+(aq) + SO42-(aq) → BaSO4(s)
If BaCl2 (Ba2+) is not taken in excess then the precipitation would not be completed as some of the sulfate ions would still be remaining in the solution. This would decrease the mass percentage of sulfate in the unknown sample.
If some tiny pieces of filter paper still remained mixed with the precipitate(BaSO4) then the mass of sulfate would increase and it gives a high mass percentage of the sulfate.
mass percentage of sulfate = (mass of sulfate/mass of sample)*100
Learn more about precipitation here https://brainly.com/question/14675507
#SPJ4
in reacting 12 moles of pb2+ ions with 18 moles of cl- ions, the theoretical molar yeild of lead (II) chloride is
The theoretical molar yield of lead (II) chloride will be 9 moles.
Stoichiometric calculationFirst, we need to look at the equation of the reaction:
[tex]Pb^{2+} + 2Cl^- --- > PbCl_2[/tex]
From the equation, the 1 mole of Pb2+ ion requires 2 moles of Cl- ion in order to produce 1 mole of lead (II) chloride.
Thus, with 18 moles Cl- ions, 9 moles of Pb2+ would be needed, instead of 12 moles. Pb2+ is simply in excess while Cl- can be said to be limiting.
Therefore, Cl- will determine how much of lead (II) chloride that will be produced. The ratio is 2 moles of Cl- to 1 mole of lead (II) chloride.
With 18 moles Cl-, 9 moles of lead (II) chloride will, thus, be produced.
More on mole ratios can be found here: https://brainly.com/question/14425689
#SPJ1
7.How would the number of moles (n) of O2 change if your atmospheric pressure was doubled and all other variables stayed the same
The number of moles (n) of O2 will be double if atmospheric pressure was doubled and all other variables stayed the same.
About Ideal gas LawThe general gas equation, often known as the ideal gas law, is the equation of state for a fictitious ideal gas. It has a number of limitations, but it provides a decent approximation of the behavior of numerous gases under various circumstances.
Explanation:Applying the law of ideal gas: PV = nRT.
where,
P= pressure of the gas in the atm.
V= volume of the gas in L.
n = no. of moles of the gas in mol.
R = Universal gas constant,
T = temperature of the gas in K.
If V and T are constant and have different values of P and n:
(P₁n₂) = (P₂n₁).
P₂ = 2P₁,
∴ n₂ = (P₂n₁)/(P₁) = (2P₁n₁)/(P₁) = 2n₁.
therefore if we double the pressure then no. of the moles of O2 will be doubled.
Learn more about Pressure here:-
https://brainly.com/question/27533579
#SPJ4
Hydrogen gas can be produced by the reaction of magnesium metal with hydrochloric acid by the reaction below. mg 2hcl → mgcl2 h2 if 4.00 g of mg is reacted with 3.20 g of hcl, what is the limiting reactant? mg hcl
The limiting reactant will be HCl.
Limiting reactantsThey limit the amount of products produced in reactions.
From the equation, the mole ratio of Mg to HCl is 1:1.
Mole of 4.00 g mg = 4/24.3 = 0.1646 moles
Mole of 3.2 g HCl = 3.2/36.458 = 0.0878 moles
Thus, Mg is in excess while HCl is limiting in availability.
More on limiting reactants can be found here: https://brainly.com/question/14225536
#SPJ1
Answer:
HCI , Excess reactant is Mg , and 4.18 g MgCl
Please help Please help
The atomic number of the element witch does not usually form compounds because it's outermost shell is full
The atomic numbers of elements with a filled outermost shell are 2, 10, 18, etc.
What are noble gases?
Noble gases are elements on the periodic table with filled outermost shells.
With filled outermost shells, these elements are not able to react in chemical reactions ordinarily.
These elements include Helium (2), Neon (10), Argon (18), etc.
More on noble gases can be found here: https://brainly.com/question/11764545
#SPJ1
he naturally occurring form of a metal that is concentrated enough to allow economical recovery of the metal is known as Multiple Choice an element. a mineral. gangue.
The naturally occurring form of a metal that is concentrated enough to allow economical recovery of the metal is known as D)ores.
Ore is natural rock or sediment that consists of one or more valuable minerals, commonly containing metals, that can be mined, handled, and offered at a profit. Ore is extracted from the earth thru mining and treated or subtle, often via smelting, to extract the precious metals or minerals.
Ore is a deposit in Earth's crust of one or greater valuable minerals. The maximum valuable ore deposits include metals crucial to industry and alternate, like copper, gold, and iron. Copper ore is mined for ramification of industrial uses.
Ores are minerals that have a high awareness of a sure detail, commonly metallic. Examples are cinnabar (HgS), an ore of mercury, sphalerite (ZnS), an ore of zinc, cassiterite (SnO2), and an ore of tin (Mineral).
Learn more about Ores here: https://brainly.com/question/89259
#SPJ4
Hydrometallurgy uses __________________ to separate a metal from its ore. Multiple Choice solid phase chemical properties electrical processes thermal processes aqueous chemical processes molten salt processes
Hydrometallurgy uses electrical processes.
Hydrometallurgy can be defined as a steel healing method used to gain metals from ores and waste materials with the usage of aqueous media via combining water, oxygen, and other chemical reagents without or with the use of pressurized surroundings.
That is a method of metal or steel compound extraction from ore via pre-remedies that contain the use of a bleaching agent, separation of impurities, and precipitation. It's far used in the extraction of uranium, gold, zinc, silver, and copper from low-grade ores.
In hydrometallurgy, zinc and iron can be used to displace copper from their answer. But to displace zinc, extra reactive metals i.e., metals having decreased reduction potentials than zinc along with Mg, Ca, ok, etc. are required. ... for this reason, copper may be extracted by means of hydrometallurgy but no longer zinc.
Learn more about Hydrometallurgy here https://brainly.com/question/28040392
#SPJ4
defination of dative covalent bond
In coordination chemistry,
A coordinate covalent bond also known as a dative bond, dipolar bond, or coordinate bond is a kind of two-center, two-electron covalent bond in which the two electrons derive from the same atom. The bonding of metal ions to ligands involves this kind of interaction.
☆...hope this helps...☆
_♡_mashi_♡_
Which safety data sheet section includes chemical abstract service number, european commission number and european chemical agency number?
The safety data sheet section which includes chemical abstract service number, european commission number and european chemical agency number are section3 and section 1 respectively.
Section 3 lists the ingredients, including stabilizers and contaminants, that are present in the product mentioned on the SDS. Information on compounds, concoctions, and any chemicals where a trade secret is asserted is provided in this section. The following details must be included in this section are Chemical Abstract Service (CAS) number and other unique identifiers.
The Safety Data Sheet(SDS's) compounds are listed in Section 1 along with suggested applications. It also offers the supplier's contact details. This section must have the following information of name, location, contact information, and emergency phone number for the manufacturer, importer, or other accountable party like European commission number and European chemical agency number.
Learn more about safety data sheet here -
https://brainly.com/question/21526755
#SPJ4
To which group does copper belong?
a. Metalloid
b. Alkaline earth metal
c. Alkali metal
d. Transition metal
Answer:
d. Transition metal
Explanation:
A transition metal is an element which has an atom or forms an ion with a partially-filled d-subshell.
As we can see from the electronic configuration of Copper 2+ ion, Cu²⁺:
[tex]_{27}Cu^{2+} = 1s^2\space\ 2s^2 \space\ 2p^6 \space\ 3s^2 \space\ 3p^6 \space\ 3d^9[/tex] ,
copper forms an ion with an incomplete d-subshell that contains 9 electrons; therefore copper is a transition metal.
• Option a. is wrong because copper is not a metalloid. Metalloids have characteristics of both metals and non-metals; copper only has metallic properties.
• Option b. is wrong because 'alkaline earth metals' are the elements in Group 2 of the periodic table; copper is in Group 11.
• Option c. is wrong because 'alkali metals' are in Group 1 of the periodic table.
Write the correct chemical formula for hexacyanoferrate (III) ion.
Which is the correct chemical name for Fe(CN)6^4-?
Which is the correct chemical name for Zn(OH)4^2–?
Write the correct chemical name for PtCl6^2–
Which is the correct chemical name for Cr(OH)4^2–?
C6FeN6⁻³ is the correct chemical formula for hexacyanoferrate (III) ion.
What is Chemical formula?This contains information about the proportion of atoms present inn a chemical compound.
The correct chemical name for Fe(CN)6^4- is Ferrocyanide.The correct chemical name for Zn(OH)4^2– is Tetrahydroxidozincate(II).The correct chemical name for PtCl6^2– is Hexachloridoplatinate(IV) ion.The correct chemical name for Cr(OH)4^2– is Tetrahydrochromate.Read more about Chemical formula here https://brainly.com/question/26388921
#SPJ1
The closeness of particles of gas and their low speeds allow intermolecular forces to become important at certain pressures and temperatures. Which best describes this statement?
A) This is a limitation of the kinetic-molecular theory.
B) This is a postulate of the kinetic-molecular theory.
C) This describes ideal gas behavior using the kinetic-molecular theory.
D) This describes ideal gas behavior without the kinetic-molecular theory.
It is a limitation of the kinetic-molecular theory because closeness and low speed don't allow intermolecular forces to become important at certain pressure and temperature.
The kinetic gas theory explains micro-particles (atoms and molecules). The kinetic theory is basically based upon the assumption of microscopic particles . We can use it as a microscopical model.
And the kinetic theory of gases explains how gases behave by assuming that they are made up of quickly moving atoms or molecules.
Basically kinetic model is based on the below assumptions.-
I t is assumed that the gas is made by a large number of identical molecules. And molecules are moving in random directions. And also separated by the large distances as compared to their size.
The molecules collide completely elastically without no energy loss.
Always kinetic energy is transferred between molecules through heat.
Learn more about kinetic molecular theory here:
https://brainly.com/question/7541718
#SPJ10
What is the Bronsted-Lowry definition of an acid?
• a compound that donates protons
a compound that accepts protons
• a substance that increases hydroxide ion concentration
a substance that increases hydronium ion concentration
Answer:
A. a compound that donates protons
Explanation: According to the Brønsted-Lowry definition, an acid is a substance that can donate a proton (H+ ion) to another molecule. A base is a substance that can accept that donated H+. After the Brønsted-Lowry acid donates its proton, it becomes the conjugate base of the acid.
Answer:
A: a compound that donates protons.
Explanation:
please give me brainiest.
What is the variable that is changed by
the experimenter called?
a. control variable
b. independent/manipulated variable
c. dependent/responsive variable
d. hypothesis
Answer:
b. independent/manipulated variable
Explanation:
Independent/manipulated variable - refers to the variable that is changed by the scientist or an experimenter. Only one variable that is independent is required to ensure a fair test in an excellent experiment. As the independent variable is being changed by an experimenter or scientist, data is being recorded simultaneously as they are collected.
Carl has an empty 35.0-liter tank that he wants to fill with 18.3 moles of oxygen gas. The gas in the tank will have a temperature of 25°C. If the air surrounding the tank is at standard pressure, what will be the gauge pressure of the oxygen in the tank in atmospheres?
The gauge pressure of the oxygen in the tank in atmospheres is 11.46 atm.
What is gauge pressure?
The gauge pressure is given as the pressure relative to the ambient atmospheric pressure. The gauge pressure can be calculated as:
Gauge pressure = System pressure - Atmospheric pressure
The system pressure of the 35-liter tank with 18.3 moles oxygen is given as:
Pressure = moles * Rydberg constant * Temperature / Volume
Pressure = 18.3 moles * 0.08 L.atm.mol⁻¹.K⁻¹ * 298 K / 35 L
Pressure = 12.46 atm
The standard pressure is given as 1 atm.
Thus, the gauge pressure of the oxygen in the tank can be:
Gauge pressure = System pressure - Atmospheric pressure
Gauge pressure = 12.46 atm - 1 atm
Gauge pressure = 11.46 atm
The gauge pressure of the oxygen in the tank in atmospheres is 11.46 atm.
Learn more about gauge pressure, here:
https://brainly.com/question/15734722
#SPJ1
Answer:
The answer is 8.31 atm.
Explanation:
Ideal Gas Law = PV = nRT
(where P is pressure, V is volume, n is the number of moles, R is the ideal gas constant, and T is the temperature in Kelvin.)
First, convert the temperature from Celsius to Kelvin:
25°C + 273.15 = 298.15 K
Next, plug in the known values into the Ideal Gas Law equation:
P * 35.0 L = 18.3 moles * 8.31 J/mol*K * 298.15 K
Finally, solve for P:
P = (18.3 moles * 8.31 J/mol*K * 298.15 K) / 35.0 L
The pressure is in units of joules per liter. To convert it to atmospheres, divide by the atmospheric pressure in joules per liter:
1 atm = 101,325 Pa = 101,325 J/m^3 = 101.325 kPa
P (in atm) = (18.3 moles * 8.31 J/mol*K * 298.15 K) / (35.0 L * 101.325 kPa)
= 8.31 atm
Alpha particles are identical to Multiple Choice protons. helium atoms. hydrogen atoms. helium nuclei.
Alpha particles are identical to Helium Nuclei.
What is Alpha Particle ?An alpha particle is subatomic particle which consist two protons and two neutrons tightly bound together. Alpha particle is identical to nucleus of helium atom. Alpha particle is a positively charged particle. Alpha particle is also known as Alpha radiation or Alpha ray.
What is Helium ?Helium is a chemical element. The symbol of Helium is He. Atomic number of helium is 2. It is a colourless gas. Helium belongs to period 2.
Thus from the above conclusion we can say that Alpha particles are identical to Helium Nuclei.
Learn more about the Alpha Particle here: https://brainly.com/question/1621903
#SPJ4
In the following neutralization reaction 2CsOH(aq) H2SO4(aq), the salt produced will be _______________
The salt produced by the neutralization of 2CsOH(aq) and H₂SO₄(aq) is Cesium Sulphate - Cs₂SO₄.
What is neutralization reaction?The neutralization reaction takes place between an acid and a base to produce a salt and water. The salt formed in the neutralization process is an ionic compound that consisting of an anion from the acid and a cation from the base.Neutralization reaction for the given compounds:The given compounds are
2CsOH - a strong base and H₂SO₄ - a strong acid
When they react with one another, the neutralization takes place and forms a neutral compound Cs₂SO₄ called as a salt.
The reaction is as follows:
2CsOH(aq) + H₂SO₄ → Cs₂SO₄ + H₂O
Therefore, the salt produced will be Cs₂SO₄(Cesium sulphate).
Learn more about neutralization here:
https://brainly.com/question/203541
#SPJ4
A 600 dm3 sample of hydrogen gas was collected contain at 950mm of hg pressure at room temperature.
The new volume of the hydrogen gas at s.t.p., [tex]V_{2}[/tex] = 750 dm³
What is the molar volume of gas at s.t.p?The molar volume of a gas at s.t.p. is 22.4 dm³.
The change in volume gases at different temperatures and pressures are given by the general gas equation given below:
[tex]\frac{P_{1}V_{1}}{T_{1}} = \frac{P_{2}V_{2}}{T_{2}}[/tex][tex]V_{1}[/tex] = 600 dm³
[tex]P_{1}[/tex] = 950mmHg
[tex]T_{1}[/tex]= 273 K
The new volume of the hydrogen gas at s.t.p., [tex]V_{2}[/tex] is calculated thus:
[tex]V_{2}[/tex] = (950 x 600 x 273)/(760 x 273) = 750 dm³
In conclusion, the volume of a gas changes with temperature and pressure changes.
Learn more about gas volume at: https://brainly.com/question/27100414
#SPJ1
Which of the following are products when magnesium metal is placed in hydrochloric acid? (Correct answer should be D but why)
A-H
B-H+
C-Mg
D-MgCl2
Answer:
an acid +metal =salt +hydrogen
Explanation:
HCL+Mg =Mgcl2+H2
(because Mg has an ion with a +2 charge ,it attracts Cl with a -2 charge )
therefore the correct answer is D for the above reasons
Answer:
When magnesium reacts with hydrochloric acid (HCl), a single-replacement reaction occurs. These reactions involve the substitution of one element in a compound with another. In this case, the hydrogen in HCl will be swapped with the magnesium metal because both of these elements make cations (positively-charged ions) when they participate in ionic bonding.
So why does the chorine have a subscript of 2 when it bonds with magnesium? This occurs in order to balance the ionic charges and make the overall compound neutral.
Magnesium wants to give away 2 electrons when it ionizes, forming the cation Mg²⁺. However, chlorine only wants to gain 1 electron to fill its valence shell, making it form the anion, Cl⁻. As you can see, if just one of each ion were to bond, the compound would have an overall charge of +1 because (+2 - 1 = +1). Therefore, the compound can be made neutral if two chlorine ions bond with just 1 magnesium ion (+2 - 1 - 1 = 0).
The hydrogen ion from HCl becomes H₂ after the reaction occurs. This occurs because hydrogen generally exists as a diatomic compound in nature (diatomic = exists as 2 atoms).
The complete balanced equation for the reaction is:
Mg + 2 HCl ------> MgCl₂ + H₂
What are some of the reasons why the United States did not adopt the metric system of measure?
at the time most of its trade was with France who did not use the metric system
the House of Representatives defeated the bill calling for conversion to metrics in 1974
the US was waiting for all other industrialized countries to adopt it before proceeding
at the time most of its trade was with England and Canada who did not use the metric system
The United States was waiting for all other industrialized countries to adopt it before proceeding.
Why the United States did not adopt the metric system of measure?The big reasons the U.S. hasn't adopted the metric system are simply time and money. When the Industrial Revolution began in the country, expensive manufacturing plants became a main source of American jobs and consumer products so money for the installation of new system.
So we can conclude that the US was waiting for all other industrialized countries to adopt it before proceeding.
Learn more about metric system here: https://brainly.com/question/1837503
#SPJ1
The House of Representatives defeated the bill calling for conversion to metrics in 1974. Option B
What is the metric system?The metric system is the most current system of measurement which is generally accepted in the scientific world. It is the system of measurement that is widely reported in scientific literature.
The reason why the United States have not officially adopted the metric system is that the House of Representatives defeated the bill calling for conversion to metrics in 1974.
Learn more about the metric system:https://brainly.com/question/10909044
#SPJ1
The partial pressure of oxygen in the alveoli is _______ mm Hg, while the partial pressure of carbon dioxide in the alveoli is _______ mm Hg.
The partial pressure of oxygen in the alveoli is about 104 mm Hg, while the partial pressure of carbon dioxide in the alveoli is 40 mm Hg.
What is the partial pressure of gases in the alveoli?The alveoli are tiny air sacs where gaseous exchange takes place between the lung and the bloodstream.
Because oxygen needs to diffuse into the bloodstream while carbon dioxide needs to diffuse out, the partial pressure of oxygen in the alveoli is around 104 mmHg while that of carbon dioxide is 40 mmHg.
With higher partial pressure than in the blood, oxygen from the alveoli will be able to diffuse into the blood. With lower partial pressure than in the blood, carbon dioxide will be able to diffuse from the blood into the alveoli.
More on the partial pressure of gases in the alveoli can be found here: https://brainly.com/question/14170500
#SPJ1
Which situation would cause a red for an observer on the red planet?
How are the products represented in the chemical equation for photosynthesis? o2 6co2 c6h12o6 6h2o 6co2 6h2o c6h12o6 6o2
The chemical equation for photosynthesis is 6CO2+6H2O→C6H12O6+6O2. 6CO2+6H2O→C6H12O6+6O2.
In plants, the process of photosynthesis takes place in the mesophyll of the leaves, inside the chloroplasts.
Photosynthesis is the technique with the aid of which inexperienced plant life and positive other organisms remodel light electricity into chemical strength.
During photosynthesis in green flowers, mild strength is captured and used to convert water, carbon dioxide, and minerals into oxygen and energy-wealthy organic compounds.
Learn more about photosynthesis here: https://brainly.com/question/3529377
#SPJ4
Answer:
The answer is actually:
D
Explanation:
Which of the following could have the formula XY₂?
Answer: B
Explanation:
There is an atom of one type of element and then two atoms of another type of element.
Combustion analysis is performed on 0.50 g of a hydrocarbon, and 1.47 g of CO2 and 0.902 g of H2O are produced. What is the empirical formula of the hydrocarbon? If the molar mass is 30.00 g/mol , what is the molecular formula?
1. The empirical formula of the hydrocarbon is CH₃
2. The molecular formula of the hydrocarbon is C₂H₆
How to determine the mass of Carbon Mass of CO₂ = 1.47 gMolar mass of CO₂ = 44 g/mol Molar of C = 12 g/mol Mass of C =?Mass of C = (12 / 44) × 1.47
Mass of C = 0.4 g
How to determine the mass of HMass of compound = 0.5 gMass of C = 0.4 gMass of H = ?Mass of H = (mass of compound) – (mass of C)
Mass of H = 0.5 – 0.4
Mass of H =0.1 g
1. How to determine the empirical formula C = 0.4 gH = 0.1 gEmpirical formula =?Divide by their molar mass
C = 0.4 / 12 = 0.03
H = 0.1 / 1 = 0.1
Divide by the smallest
C = 0.03 / 0.03 = 1
H = 0.1 / 0.03 = 3
Thus, the empirical formula of the compound is CH₃
2. How to determine the molecular formulaEmpirical formula = CH₃Molar mass = 30 g/molMolecular formula =?Molecular formula = empirical × n = mass number
[CH₃]n = 30
[12 + (3×1)]n = 30
15n = 30
Divide both side by 15
n = 30 / 15
n = 2
Molecular formula = [CH₃]n
Molecular formula = [CH₃]₂
Molecular formula = C₂H₆
Learn more about empirical formula:
https://brainly.com/question/24297883
#SPJ1
Charcoal found under a stone at Stonehenge, England, has a carbon-14 activity that is 0.60 that of new wood. How old is the charcoal
Charcoal with a carbon-14 activity of 0.60 compared to new wood has less than 5,730 years.
What is a radioactive isotope?A radioactive isotope is an element in nature that emit radioactivity in a given period of time (e.g., the half-life for C14 is equal to 5,730 years).
Radioactive dating is a technique to measure the age of an element by measuring its radioactive activity.
In conclusion, charcoal with a carbon-14 activity of 0.60 compared to new wood has less than 5,730 yr.
Learn more about radioactive dating here:
https://brainly.com/question/8831242
#SPJ1
The specific gravity of 10 ml of urine should be __________ the specific gravity of 10 ml of distilled water
The specific gravity of urine:
The specific gravity of 10ml of urine should be greater than the specific gravity of 10ml of distilled water.
What is specific gravity?
The comparison of the densities of solutes and water is done using specific gravity. Therefore, the following equation, where "D" stands for "density," can be used to represent particular gravity:
USG = [tex]\frac{D solutes}{Dwater}[/tex]
There are no units listed for specific gravity. A typical specific gravity value should range from 1.005 to 1.030. Accordingly, urine ought to be only a little bit denser than water. Low specific gravity is one with a value below 1.005, whereas a high specific gravity is one with a value above 1.030.
The density of the sample is increased by the presence of dissolved solutes in urine that are absent from distilled water.
Learn more about specific density here,
https://brainly.com/question/19569182
#SPJ4