Answer: Fe hóa trị II trong các hợp chất: FeSO4, Fe(OH)2
Fe hóa trị III trong các hợp chất: Fe2(SO4)3, Fe(OH)3
Explanation:
A student was given a 2.850-g sample of a mixture of potassium nitrate and potassium bromide and was asked to find the percentage of each compound in the mixture. She dissolved the sample and added a solution that contained an excess of silver nitrate, AgNO3. The silver ion precipitated all of the bromide ion in the mixture as AgBr. It was filtered, dried, and weighed. Its mass was 1.740 g. What was the percentage of each compound in the mixture
Answer:
See explanation
Explanation:
The reaction occurs as follows;
KBr(aq) + AgNO3(aq) ----> AgBr(s) + KNO3(aq)
Number of moles of AgBr formed = mass /molar mass =1.740 g/187.77 g/mol = 0.0093 moles
From the reaction equation;
1 mole of KBr yields 1 mole of AgBr
Hence the number of moles of KBr reacted = 0.0093 moles
Mass of KBr present = 0.0093 moles × 119g/mol = 1.11 g
Mass of KNO3 = 2.850 g - 1.11 g = 1.74 g
Percentage of KBr = 1.11 g/2.850 g × 100 = 38.9%
Percentage of KNO3 = 1.74 g/2.850 g × 100 = 61.1%
PLEASE HELP ASAP
Barney was a very inventive scientist and tried to perform the same experiments as those by famous scientists from long ago. One of the most challenging experiments was to roll out a very thin film of gold and put X-ray film in a circle around it. The difficult part was to get ahold of some radioactivity that he could shoot at the thin film for gold. One day, he ran into The Great Gazoo and told him his goal. The Great Gazoo said he had the perfect substance for him that was radioactive and should work. The element was named after him and had the symbol Gz. Barney quickly went back to his lab to run the experiment. What Barney noticed is that all the radioactive particles went through the gold film and none of them ricocheted back, but all went straight through the gold. Being puzzled, he quickly went to the lab to analyze this unknown radioactive substance. He found that the atomic number was 119, the mass number was 305. After a few more tests, Barney realized what was wrong with Gz. Your task is to figure out what was wrong with Gz by answering the following questions:
Whose experiment was Barney trying to imitate?
Where would Gz be located on Earth’s periodic table, column and row?
Give as many details on Gz that you could predict based on its location on the periodic table: type of chemical (metal, metalloid, or nonmetal), reactivity, ionization energy, electronegativity, and size of element.
What would the elements electron configuration end in?
Why did all the radioactive particles go straight through the gold film?
What would the daughter product be for Gz? Give all details for the atomic number, mass number, number of protons, neutrons and electrons.
If Gz had worked correctly, like Barney intended, what type of decay should Gz have had?
If Gz had worked correctly, what would the daughter product be? Give all details for the atomic number, mass number, number of protons, neutrons and electrons.
If Gz had worked correctly, what element would it become?
Answer:
a) Barney wants to repeat the rutheford experiment
b) the element will be in row 8 column 1 being an alkali metal
c) it should be a radioactive element, with a lot of mass
Explanation:
n this exercise they indicate that the particle Gz has atomic number 119 and atomic mass 305 amu, when reviewing the element periodicity table with this atomic number it has not yet been discovered, it should be in row 8 column 1 therefore it should be an alkali metal .
Therefore, it has only one electron in its last orbit.
a) Barney wants to repeat the rutheford experiment
b) the element will be in row 8 column 1 being an alkali metal
c) it should be a radioactive element, with a lot of mass
describe how thin layer chromatography is used in the isolation and extraction of lipids
Thin layer chromatography(TLC) works with the principle of separation through adsorption.
It is used in the isolation and extraction of lipids through the following steps:
apply the lipid samples spots in the bottom of the plate.also apply sample solution to the marked spotpour the mobile phase into the TLC chamber and use a moist filter paper to cover it. this is done to maintain equal humidity.then place the plate in the TLC chamber and close it with a lid.the plate is immersed into the solvent (mobile phase) for its development. this is done, keeping in mind that the sample spot should be above the solvent.once the sample spots are developed, they are removed and dried.this is later viewed using the UV light chamber to see the isolation of the lipid sample.Learn more here:
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What is the molecular formula?Write down the molecular formula of the given compounds.
i. Calcium Sulphate
ii. Sodium Carbonate
iii. Water
iv. Carbon Dioxide
v. Potassium Nitrate
vi. Ammonium Chloride
Answer:
A molecular formula consists of the chemical symbols for the constituent elements followed by numeric subscripts describing the number of atoms of each element present in the molecule.
The molecular formula of the given compounds are:
CaSO4Na₂CO₃H2OCO2KNO3NH4ClThe gases in a hair spray can are at a temperature of 27oC and a pressure of 30 lbs/in2. If the
gases in the can reach a pressure of 90 lbs/in2, the can will explode. To what temperature must
the gases be raised in order for the can to explode? Assume constant volume. Show your work.
Using Gay Lussac's Law
[tex]\boxed{\sf \dfrac{P_1}{T_1}=\dfrac{P_2}{T_2}}[/tex]
[tex]\\ \sf\longmapsto \dfrac{30}{27}=\dfrac{90}{T_1}[/tex]
[tex]\\ \sf\longmapsto T_1=\dfrac{90\times 27}{30}[/tex]
[tex]\\ \sf\longmapsto T_1=81°C[/tex]
Key Notes:-Gay Lussac's Law:-
It states that at constant volume (V),The pressure(P) of fixed amount of gas caries directly with its absolute temperature(T).
[tex]\\ \sf\longmapsto P\propto T[/tex]
[tex]\\ \sf\longmapsto \dfrac{P}{T}=Constant[/tex]
[tex]\\ \sf\longmapsto \dfrac{P_1}{T_1}=\dfrac{P_2}{T_2}[/tex]
[tex]\\ \sf\longmapsto P_1T_2=P_2T_1[/tex]
The final temperature of the gases with 90 lbs/in² is equal to 627°C assuming the volume is constant.
What is Gay Lussac's law?Gay-Lussac's law can be described as if the volume (V) of the gas remains constant then the pressure (P) is directly proportional to the absolute temperature (T) of the gas.
Gay Lussca's law in mathematical expression can be represented as:
P/T = k
It can be also represented as the pressure (P) being directly proportional to the temperature (T).
P ∝ T ( V of gas is constant)
or, P₁/T₁ = P₂/T₂
Given, the initial temperature of the gas, T₁ = 27°C = 27 + 273 = 300 K
The initial pressure of the gas, P₁ = 30 lbs/in²
The final pressure of the gas, P₂ = 90 lbs/in²
The final temperature of the gases in a hair spray can be determined as:
[tex]{\displaystyle \frac{P_1}{T_1} =\frac{P_2}{T_2}[/tex]
[tex]{\displaystyle T_2 =\frac{P_2\times T_1}{P_1}[/tex]
[tex]{\displaystyle T_2 =\frac{90\times 300}{30}[/tex]
T₂ = 900 K = 900 - 273
T₂ = 627°C
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Hydrogen and oxygen combine in
the ratio of 1:8 by mass to form
water. What mass of oxygen gas
would be required to react
completely with 3 g of hydrogen
gas?
Answer:
hhshshhxujejushwhbwhsjs s hs
What are 5 uses of nitrogen?
Answer:
nitrogen is used in the production of 1) fertilisers 2) nitric acid 3) nylon 4) dyes and 5) explosives
please give me brainliest if you can :))
2. Calculate the density of a metal that occupies 17.75 cm and has a mass of 342.93 g. [D = m/V]
Answer:
19.32
Explanation:
the density is given by the mass over volume
the mass In this case is 342.93 and the volume is 17.75
d=342.93g/17.75cm
=19.32g/cm
i hope this helps
Define force and speed
Force = The external energy that changes or tends to change the state of any body or object is called force.
Speed = The rate of distance is called speed.
Answer:
Force is a push or pull which changes or tend to change the position of a body.
The rate of change its position with time or magnitude is called speed.
16. The valency of sodium is +1 and that of chlorine is -1, why?
Answer:
It because ,sodium is a metal and chlorine is a non metal
which chloride is a coloured solid rtp
Answer:
sodium chloride
hope that helped :)
Answer:
Chlorine is a greenish yellow gas at room temperature and atmospheric pressure. ... yielding chlorine water, and from this solution a solid hydrate of ideal ...
Describe the formation of oxygen molecule
Answer:
oxygen molecule has two oxygen atom . Each O atom share 2 electrons to form two covalent bonds out of which one is sigma bond and other is pi bond . sigma bond is formed by axial overlap 2p atomic orbitals of oxygen and pi bond is formed of lateral overlap of 2p atomic orbitals of oxygen .
Which statements are true in regard to the VSEPR theory?
Select all that apply.
Molecules acquire a shape that results in the greatest charge.
Molecules acquire a shape that minimizes the repulsions of electron groups.
Molecules acquire a shape that maximizes the distance of electron groups.
Molecules acquire a shape that results in the lowest possible energy state.
The correct option is D. 2) Anti-bonding electrons or lone pairs. These lone pairs, and bonds helps to form the shape which keeps these electrons separate as possible.
Write the empirical formula for at least four ionic compounds that could be formed from the following ions: NO3, Pb^4+, NH4, SO4
Explanation:
here's the answer to your question
double arrow just mean that it's a reversible process, and the reaction can go back and forth.
Oxide of nitrogen that is acidic
Answer:
Nitrogen oxides are used in the production of nitric acid, lacquers, dyes, and other chemicals. Nitrogen oxides are used in rocket fuels, in the nitrification of organic chemicals, and in the manufacture of explosives.
Explanation:
help me pls! plsssss
Answer:
Neutron, neutral subatomic particle that is a constituent of every atomic nucleus except ordinary hydrogen. It has no electric charge and a rest mass equal to 1.67493 × 10−27 kg—marginally greater than that of the proton but nearly 1,839 times greater than that of the electron.
write its IUPAC name?
Answer:
Hello
please make sure that there is any group which is join with alkane
A precipitation reaction 2. A Lewis acid-base reaction the produces a coordination complex: A Lewis acid-base reaction the produces a coordination complex 3. An oxidation-reduction reaction that is also a synthesis reaction: An oxidation-reduction reaction that is also a synthesis reaction Column B a. Pb2 (aq0 CrO42-(aq) --> PbCrO4(s) b. 2 Mg(s) O2(g) -> 2 MgO(s) c. Ag (aq) 2NH3(aq) --> [Ag(NH3)2] (aq)
Answer:
Pb2+ (aq) + CrO42-(aq) --> PbCrO4(s) - A precipitation reaction
2 Mg(s) + O2(g) -> 2 MgO(s) - An oxidation-reduction reaction that is also a synthesis reaction
Ag^+ (aq) + 2NH3(aq) --> [Ag(NH3)2]^+ (aq) - A Lewis acid-base reaction the produces a coordination complex
Explanation:
A precipitation reaction is one in which two aqueous reactants yields an insoluble product called a precipitate as shown in reaction 1 above.
In the second reaction Mg is oxidized from zero to + 2 while oxygen was reduced from zero to -2 as the MgO is formed hence the reaction is an oxidation-reduction reaction that is also a synthesis reaction.
In the third reaction, Ag^+ a Lewis acid reacts with NH3, a lewis base to yield the complex [Ag(NH3)2]^+.
calculate the volume of the object immersed in the water in the water in the adjoining figur.
Answer:
100 cm³
Explanation:
Hi there!
Subtract:
400 cm³ - 300 cm³
= 100 cm³
Therefore, the volume of the object is 100 cm³.
I hope this helps!
ii)The outer electronic configuration of an element is 3d8 4s2
.To which group and period it belongs?
Answer:
group ten period four. that's the answer
Cellular respiration occur within ______ of a cell.
Answer:
The mitochondria
Explanation:
Its where cellular respiration occurs
What is the volume occupied by 2.34 grams of CO2 gas at STP?
Answer:
The volume occupied by 2.34 grams of CO2 gas at STP is 1.18 L
a. For a chemistry lab final exam, a high school chemistry student was given a 1-mole sample of CaCl2 and a 1-mole sample of MgCl2 but was not told which sample was which. He was to identify the powders.
He looked up the enthalpies of formation for both of the chemicals and calculated the ΔHreaction for dissolving each powder: CaCl2 (s) Ca 2+ (aq) + 2Cl – (aq), and MgCl2 (s) Mg 2 (aq) + 2Cl – (aq). He then put each powder in a coffee-cup calorimeter and added water.
When sample A dissolved, the temperature increased by 0.74°C. When sample B dissolved, the temperature increased by 0.39°C. Which chemical was A, and which was B? Use the table of enthalpies of formation to help you. Explain your reasoning.
Ca^2+ ion is smaller than Mg^2+ ion hence it has a greater heat of formation or lattice energy.
When a crystal lattice is formed, the energy that is released if the component ions of the compound are brought together from infinity is called the lattice energy. It is the energy released when a crystal lattice is formed from its component ions.
The question lets us know that the heat released by the compounds depends on the energy released upon formation of the compound. Hence, the higher the energy released upon formation, the higher the magnitude of heat released upon dissolution of the compound.
Recall that lattice energy depends on the size of the ions. Thus, the smaller the ions, the higher the lattice energy.
Ca^2+ is smaller than Mg^2+ hence more energy is given off when CaCl2 is formed than when MgCl2 is formed.
As stated above, the greater the lattice energy, the greater the heat released when the lattice dissolves and the higher the rise in temperature.
Putting all these together, Sample A must be CaCl2 while sample B must be MgCl2.
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what is the name of this organic molecule
Answer:
C2H4 Ethylene
Explanation:
Hope it helps! :)
Complete and write net ionic equation:
NH3 + HCI->
Answer:
IONIC EQUATION OF NH3 AND HCL IS NH4CL
Suppose 'A' is a liquid aromatic compound with molecular weight 78 and burns with sooty flame. a.Give the name of the compound 'A' b.write the molecular structure of 'A' C. What is the product when 'A' is treated with ? i.conc.HNO3 with conc.H2SO4 as catalyst ii.Halogen (cl2)in presence of sunlight and mention the use of the product obtained
Aromatic compounds are compounds that contain carbon-carbon multiple bonds.
The question did not mention that a heteroatom is present in the compound so we can assume that there is none of such. In that case, the compound contains only hydrogen and carbon.
So,
(CH)n = 78
where n is the number of each atom present.
(12 +1)n = 78
n = 78/13
n = 6
The molecular formula of the compound is C6H6
When C6H6 is treated with .conc.HNO3/conc.H2SO4 the compound shown in image 1 is formed. The reaction occurs at the C-C multiple bond.
When C6H6 is reacted with chlorine in the presence of sunlight, hexachlorobenzene (shown in image 2 attached) is formed.
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Grease is applied to the moving part of machine.
Answer:
Explanation:
The moving part won't move on its own there's a force but the force isn't enough for something like a bike chain it need grease to move smoothly or else it will just be super stuck or slow.
Answer:
because grease produce more fiction which helps moving part of machine not get jamm while working
3 point different between reactant and product
Answer:
reactants
The substance(s) to the left of the arrow in a chemical equation are called reactants. A reactant is a substance that is present at the start of a chemical reaction
Explanation:
product_The substance(s) to the right of the arrow are called products . A product is a substance that is present at the end of a chemical reaction. In the equation above, the zinc and sulfur are the reactants that chemically combine to form the zinc sulfide product.
There is a standard way of writing chemical equations. The reactants are all written on the left-hand side of the equation, with the products on the right-hand side. An arrow points from the reactants to the products to indicate the direction of the reaction:
reactants → products
Reactants
1. The substances used as starting materials and which react with one another are reactants.
2. Example: In this reaction Mg and O2 are reactants.
Products
1. The substances which are formed as a result of reaction are products.
2. Example: In this reaction MgO is a product.
500kg, 42m, 675g, and 10m/s are all examples of what typed of data?b
500kg, 42m, 675g, and 10m/s are all examples of a: continuous data.
A numerical data can be defined as a data set that is expressed in numbers only or a data set consisting of numbers rather than words. A numerical data is also known as a quantitative data.
Generally, numerical data are classified into two (2) main categories and these are;
Discrete data: a discrete data is a data set in which the number of possible values are either finite or countable. Some examples are; the value of a fair die, number of pen in a box, number of eggs in a crate, etc.Continuous data: a continuous data is a data set that has infinitely many possible values and as such those values cannot be counted, which simply means they are uncountable. Any data (quantity) such as mass, height, volume, weight, density, velocity, length, pressure, temperature, speed, distance, time are generally classified as continuous data.In conclusion, mass (500 kg), height (42m), mass (675g), and speed (10m/s) are all examples of a: continuous data.
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What is the balanced form of the chemical equation shown below?
C2H5OH() + O2(9)
H2O() + CO2(9)
A. C2H5OH() + 302(9) — 3H20() + 2002(9)
B. 2C2H5OH() + O2(g) – 5H20(1) + CO2(g)
C. C2H20(1) + 202(9)
-
H20(1) + 2C02(9)
D. C2H5OH() + O2(g) → H20(1) + CO2(g)
Answer:
C2H5OH +3O2 = 2Co2+ 3H2O
Explanation:
The balanced chemical equation is C2H5OH + 302 → 3H20 + 2CO2.
What is balanced chemical equation?A balanced chemical equation is one in which the count of atoms in all of the molecules is equivalent on both sides of the equation. The balancing of a particular chemical equation is governed by the Law of Conservation of Mass.
Balancing chemical equation is shown as below:
It can be seen that the count of carbon atom in left side 2 on the other hand the count of carbon in right side only one. By multiply with 2 in right side of the reaction , equation will be balanced.
Therefore, the balanced chemical equation is C2H5OH + 302 → 3H20 + 2CO2.
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