The sample of white powder contains 47.1% K2CO3 and 0.39% Na2CO3.
Molar mass of sodium carbonate = 106 g/mol
Molar mass of potassium carbonate = 138 g/mol
Number of moles of HNO3 = 10/1000 L × 0.8903 M = 0.008903 moles
Mass of HNO3 = 0.008903 moles × 63 g/mol = 0.56 g
Mass of sample added = 1.091 g
Mass of sample left over = 0.573 g
Mass of sample reacted = 1.091 g - 0.573 g = 0.518 g
The reacted sample contains xg of Na2CO3 and (0.518 - x) g K2CO3.
Na2CO3 + 2HNO3 --> 2NaNO3 + CO2 + H2O
106g of Na2CO3 reacts with 126g of HNO3
x g of Na2CO3 reacts with (126 × x/106)g of HNO3
K2CO3 + 2HNO3 --> 2KNO3 + CO2 + H2O
138 g of K2CO3 reacts with 126 g of HNO3
(0.518 - x) g of K2CO3 reacts with [(0.518 - x) × 126/138] g
Total mass of HNO3 used;
1.19x + 0.47 + 0.91x = 0.56
2.1x + 0.47 = 0.56
2.1x = 0.56 - 0.47
2.1x = 0.09
x = 0.09/2.1
x = 0.0043 g
Mass of K2CO3 = (0.518 - x) g = 0.518 - 0.0043 = 0.5137 g
Mass percent of K2CO3 = 0.5137 g/ 1.091 g × 100/1 = 47.1%
Mass percent of Na2CO3 = 0.0043/1.091 g × 100/1 = 0.39%
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Use the diagram below to answer 3 questions
Answer:
The element X is sulfur.
Sulfur will gain 2 electrons to become an ion.
The charge of sulfide ion is (2-).
Explanation:
How could you tell if a substance has undergone a physical change or a chemical one?
Answer: Chemical changes occur when a substance combines with another to form a new substance, called chemical synthesis or, alternatively, chemical decomposition into two or more different substances. These processes are called chemical reactions and, in general, are not reversible except by further chemical reactions.
A physical change is are changes affecting the form of a chemical substance, but not its chemical composition. Physical changes are used to separate mixtures into their component compounds, but can not usually be used to separate compounds into chemical elements or simpler compounds.
pls help see attached pic for the question.
Answer: Evaporation and sublimation.
Explanation: Evaporation is the process of changing from liquid to gas, and sublimation is the process of changing from solid to gas.
Calculate the percent by mass of each element in LiClO2.
% Li:
% Cl:
% O:
ok done. Thank to me :>
Answer: Mass percent of Li: total mass Li = 6.94 g/mol. % Li = mass Li mass LiClO 2 × 100 % Li = 6 . ...
Mass percent of Cl: total mass Cl = 35.45 g/mol. % Cl = mass Cl mass LiClO 2 × 100 % Cl = 35 . ...
Mass percent of O: total mass O = 32.00 g/mol.
Explanation:
Physical change does not produce a nee substance true or false
Answer:
ooooooooh .,.,.,.,.,.,
Answer:
True
TruePhysical change – A change in the size, shape, color, or state of matter of a substance. No new substance is produced.
9. Calculate the pOH and pH of a 0.35 M solution of the weak acid HCN.
Ka HCN = 4.8 x 10-10
Answer:
=0.35hcn20 4.7 x hcn(poh) =hcnty sa pointd
Disadvantage and advantage of iodine ?
- umoren sŭm..
THE ADVANTAGE OF IODIN
IODINE CAN LEAD TO GOITER AND OTHER THYROID PROBLEMS.THE DISADVANTAGE OF IODIN
IODIN MAY LEAD TO THYROIDITIS AND THYROID PAPILLARY CANCERplease Help me !! NO LINKS! fill this chemical reaction please
Answer:
see the above attachment.
Explanation:
hope this helps you.
Plaseee ASAP
In an experiment hydrochloric acid is added drop by drop to solid sodium sulfite (Na2SO3). A gas is evolved and collected. Half of the collected gas is added to Lugol solution (I2 dissolved in KI solution), the other half of the gas is added to hydrogen sulfide solution. Write the equation of the reactions, discuss the observations that can be seen during the reactions and explain the changes. In your answer, also discuss the followings:
a) What gas is liberated during the reaction between HCl and Na2SO3? Why can it be liberated this way? Write an equation for the reaction.
b) What ability of the gas is
demonstrated in the reactions with Lugol solution and with H2S? Write equations and use oxidation numbers to prove it. What makes it possible for the substance to act differently in the two reactions?
c) What other properties of the gas evolved can you recall?
d) What are the environmental implications of the gas evolved? Write the appropriate equation for the reaction.
SO2 acts both as an oxidizing and a reducing agent depending on the conditions of the reaction. It also leads to acid rain.
The reaction of HCl with Na2SO3 occurs as follows;
Na2SO3 + 2HCl ------> 2NaCl + SO2 + H2O
The gas evolved in the reaction is SO2. It is liberated because sulfites react with acids to liberate sulfur IV oxide.
The ionic equation of the reaction is; [tex]SO3^2-(aq) + 2H^+(aq) ----> SO2(g) + H2O(l)[/tex]
The reaction of SO2 with Lugol solution occurs as follows;
SO2 +I2 + 2H20→ H2SO4 + 2HI. This demonstrates oxidation because sulfur is oxidized from +4 to +6 state from left to right. This shows SO2 as a reducing agent.
With H2S, the gas reacts as follows;
2H2S + SO2 → 3S (s) + 2H2O
The oxidation number of sulfur decreases from +4 to zero. This demonstrates the gas as an oxidizing agent. SO2 can act as oxidizing or reducing agent because it can change its oxidation state to +6(oxidation) by electron loss or gain electrons to decrease its oxidation state as low as -2.
The gas SO2 is an acid gas. It dissolves in water to yield an acid solution. Also SO2 is a bleaching agent. The major environmental impact of SO2 is that it leads to acid rain as follows; 2SO2 + O2 + 2H2O⇌2H2SO4.
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6. How will you obtain ? (a) Magnesium oxide from magnesium. (b) Silver chloride from silver nitrate. (c) Nitrogen dioxide from lead nitrate. (d) Zinc chloride from zinc. (e) Ammonia from nitrogen. Also give balanced equations for the reactions.
plx answer this question
Answer:
a) reaction with oxygen
2mg +o2---------2mgo
b) Agno3+NaCl ----------AgCl+NaNo3
What happens to the particles of air inside a ball it warms in the sun?
Answer:
The particles start moving faster and expand making the ball expand.
Explanation:
What is caused by temperature differences in the mantle resulting in plate movement?
Crust
Convection Currents
Lithosphere
Answer:
Convection Currents
Explanation:
Which of the following has the greatest mass?
A) One mole of mercury
B) One mole of barium
C) One mole of gold
D) They all have the same mass
Answer:one mole of gold
An example of kinetic energy being converted into heat energy
Answer:
if you drop a water balloon onto the ground, its kinetic energy is converted mostly to thermal energy. If the balloon weighs 1 kilogram and you drop it from about 2 meters, it will heat up by less.
Explanation:
As you say, kinetic energy of large objects can be converted into this thermal energy. For example, if you drop a water balloon onto the ground, its kinetic energy is converted mostly to thermal energy. If the balloon weighs 1 kilogram and you drop it from about 2 meters, it will heat up by less than.
list atleast two examples of Arrhenius acids?
Answer:
HCl (hydrochloric acid) and H2SO4 (sulphuric acid)
I hope it helps.
A chemist heats the block of copper as shown in the interactive, then places the metal sample in a cup of oil at 25.00 °C instead of a cup of water. The temperature of the oil increases to 27.33 °C . Calculate the mass of oil in the cup. The specific heat of copper is 0.387 J/g⋅°C and the specific heat of oil is 1.74 J/g⋅°C .
When the oil is added to the heated copper, the energy in the system is
conserved.
The mass of the oil in the cup, is approximately 64.73 grams.Reasons:
The question parameters are;
Temperature of the oil in the cup = 25.00°C
Final temperature of the oil and copper, T₂ = 27.33 °C
Specific heat of copper, c₂ = 0.387 J/(g·°C)
Specific heat capacity of oil, c₁ = 1.74 J/(g·°C)
Required:
The mass of oil in the cup.
Solution:
The mass of the copper, m₂ = 17.920 g
Temperature of copper after heating, T₂ = 65.17°C
Temperature of the copper after being placed in the cup of oil, T₂ = 27.33°C
Heat lost by copper = Heat gained by the oil
m₂·c₂·(T₂ - T₃) = m₁·c₁·(T₃ - T₁)Therefore, we get;
17.920 × 0.387 × (65.17 - 27.33) = m₁ × 1.74 × (27.33 - 25)
262.4219136 = 4.0542·m₁
m₁ ≈ 64.73
The mass of the oil in the cup, m₁ ≈ 64.73 gLearn more here:
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Possible part of the question obtained from a similar question online, are;
The mass of the copper, m₂ = 17.920 g
Temperature of copper after heating = 65.17°C
Balance the following redox reaction if it occurs in acidic solution. What are the coefficients in front of Ni and H+ in the balanced reaction? Ni2+(aq) + NH4+(aq) → Ni(s) + NO3-(aq)
In this case, the problem is asking for the balance of a redox reaction in acidic media, in which nickel is reduced to a metallic way and nitrogen oxidized to an ionic way.
Thus, according to the given information, it turns out possible for us to balance this equation in acidic solution by firstly setting up the half reactions:
[tex]Ni^{2+}+2e^-\rightarrow Ni^0\\\\N^{3-}H_4^++3H_2O\rightarrow N^{5+}O_3^-+8e^-+10H^+[/tex]
Next, we cross multiply each half-reaction by the other's carried electrons:
[tex]8Ni^{2+}+16e^-\rightarrow 8Ni^0\\\\2N^{3-}H_4^++6H_2O\rightarrow 2N^{5+}O_3^-+16e^-+20H^+[/tex]
Finally, we add them together to obtain:
[tex]8Ni^{2+}+2N^{3-}H_4^++6H_2O\rightarrow 8Ni^0+2N^{5+}O_3^-+20H^+[/tex]
Which can be all simplified by a factor of 2 to obtain:
[tex]4Ni^{2+}+N^{3-}H_4^++3H_2O\rightarrow 4Ni^0+N^{5+}O_3^-+10H^+\\\\4Ni^{2+}(aq)+NH_4^+(aq)+3H_2O(l)\rightarrow 4Ni(s)+NO_3^-(aq)+10H^+(aq)[/tex]
Hence, the coefficients in front of Ni and H⁺ are 4 and 10 respectively.
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https://brainly.com/question/149656255. If 10.0 gram of aluminum chloride are decomposed, how many molecules of Cl, are
produced?
Answer: 6.77*1022 Molecules
Explanation: :)
outline the properties of alkanes
Answer:
Physical Properties of Alkanes : -
1. Structures of Alkanes
All the carbon atoms present in an alkane are s p 3. Hybridized that is, every carbon atom forms four sigma bonds with carbon or hydrogen atoms. General configuration of alkane is C n H 2 n + 2. They exhibit tetrahedral geometry with a bond angle of 109.47° between them. The methane molecule has a symmetrical tetrahedral structure.2. Solubility of Alkanes
Due to very little difference of electronegativity between carbon and hydrogen and covalent nature of C-C bond or C-H bond, alkanes are generally non-polar molecules. As we generally observe, polar molecules are soluble in polar solvents whereas non-polar molecules are soluble in non-polar solvents. Hence, alkanes are hydrophobic in nature that is, alkanes are insoluble in water. However, they are soluble in organic solvents as the energy required to overcome the existing Van Der Waals forces and generate new Van Der Waals forces is quite comparable.3. Boiling Point of Alkanes
As the intermolecular Van Der Waals forces increase with the increase of the molecular size or the surface area of the molecule we observe. The boiling point of alkanes increases with increasing molecular weight. The straight-chain alkanes are observed to have a higher boiling point in comparison to their structural isomers.4. Melting Point of Alkanes
The melting point of alkanes follows the same trend as their boiling point that is, it increases with an increase in molecular weight. This is attributed to the fact that higher alkanes are solids and it’s difficult to overcome intermolecular forces of attraction between them.It is generally observed that even-numbered alkanes have higher trend in melting point in comparison to odd-numbered alkanes as the even-numbered alkanes pack well in the solid phase, forming a well-organized structure which is difficult to break.Chemical Properties of Alkanes
Alkanes are the least reactive type of organic compound. Alkanes are not absolutely unreactive. Two important reactions that they undergo are combustion, which is the reaction with oxygen and halogenation, which is the reaction with halogens.
1. Combustion
A combustion reaction is a chemical reaction between a substance and oxygen that proceeds with the evolution of heat and light. Alkanes readily undergo combustion reactions when ignited. \When sufficient oxygen is present to support total combustion then carbon dioxide and water are the products.CH2 + 2O2 → CO2 + 2H2O + energy
2C6H14 + 19O2 → 12CO2 + 14H2O + energy
The exothermic nature of alkane combustion reactions explains the extensive use of alkanes as fuels. Natural gas, used in home heating is predominantly methane.2. Halogenation
Halogenation of an alkane produces a hydrocarbon derivative in which one or more halogen atoms have been substituted for hydrogen atoms. An example of an alkane halogenation reaction is
CH3 - CH3 + Br2 → CH3 - CH2 - Br + HBr
Alkane halogenation is an example of a substitution reaction a type of reaction that often occurs in organic chemistry. A general equation for the substitution of a single halogen atom for one of the hydrogen atoms of an alkane is
R - H + X2 → R - X + H - X
Explanation:
Chemical properties of mercury hg
Answer:
Mercury has a relatively high vapour pressure and the highest volatility of any metal, vapourizing to become a colourless, odourless gas. The metal is a fair conductor of electricity, but a poor conductor of heat. Mercury's atomic number is 8.
PLEASE HELP!!
ATTACHMENT BELOW
Answer:
read the story
Explanation:
read it and then you will find the answer
Thin-layer chromatography explain ?????
Answer:
Explanation:
Thin-layer chromatography (TLC) is a chromatography technique used to separate non-volatile mixtures. ... After the sample has been applied on the plate, a solvent or solvent mixture (known as the mobile phase) is drawn up the plate via capillary action.
Complete and balance the following redox reaction in basic solution
Cr2O7^2-(aq) + Hg(l) ----> Hg^2+(aq) + Cr^3+(aq)
Answer:
balanced in ACID not BASE
Cr2O7^2-(aq) +3Hg(l) +14 H^1+ ----> 3Hg^2+ + 2Cr^3+(aq) + 7H2O
Answer
Cr2O7^2-(aq) +3Hg(l) +14 H^1+ ----> 3Hg^2+ + 2Cr^3+(aq) + 7H2O
Explanation:
Cr2O7^2-(aq) + Hg(l) ----> Hg^2+(aqH) + Cr^3+(aq)
add H^1+ (acid) to capture the O and make 7 water molecules
Cr2O7^2-(aq) + Hg(l) + H^1+ ----> Hg^2+(aqH) + Cr^3+(aq) + 7H2O
Cr goes from +6 to +3 by gaining 3 e
Hg goes from 0 to +2 by losing 2 e
we need 3 Hg for every 2 Cr
so
Cr2O7^2-(aq) +3Hg(l) +14 H^1+ ----> 3Hg^2+ + 2Cr^3+(aq) + 7H2O
2 Cr on the right and left
Net 12 positive charges on the right and the left
3 Hg on the right and left
14 H on the right and left
the equation is balanced
we cannot balance the equation in a basic solution with OH^1-
we have plenty of O in the dichromate ion. we need to convert it to water which take free H^1+ from the acid
What is the density of a sponge that has a mass of 100g and a volume of 10 mL?
Answer:
10
Explanation:
Equation: d = m/v
100/10 = 10
Are the 3 right for number 12?
A mixture of solids containing a ketone, a carboxylic acid, and an amine, are dissolved in DCM. What is the best way to begin an extraction to separate the amine from the mixture
There are different ways of extraction. The best way to begin an extraction to separate the amine from the mixture is to extract with dilute NaOH.
An acid-base extraction is often used in the extraction of carboxylic acids from the organic layer and thereafter into the aqueous layer.NaOH is known to be the most common compound that is used to convert a carboxylic acid into its more water-soluble ionic carboxylate form.
But if the mixture has a compound that you want, and that can react with NaOH, another milder base such as sodium bicarbonate is preferably used.
See full question below
A mixture of solids containing a ketone, a carboxylic acid, and an amine, are dissolved in DCM. What is the best way to begin an extraction in order to separate the carboxylic acid from the mixture?
A) Extract with dilute NaOH
B) Extract with dilute HCl
C) Extract with dichloromethane
D) Extract with water
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In a reaction, 0.209 moles of gas is evolved. Given that the pressure is 0.669 atm and the volume of the gas is 7.30 L, calculate the
temperature of the gas in Kelvin, giving your answer to three significant figures.
The value of R is 0.0821 L'atm-K-1.mol-1
Temperature =
Kelvin
A student mixes some soap with water and then blows through a straw into the solution. Bubbles form. Do you think a chemical change has taken place? Explain
Answer:
No it has not.
Explanation:
The actual chemical compound has not changed, the materials have mixed but no reaction has taken place. Blowing the bubbles causes a physical change. Hope this helped!
Mixing soap and water and forming bubbles is a physical change as there is no change in composition.
What is a physical change?
Physical changes are defined as changes which affect only the form of a substance but not it's chemical composition. They are used to separate mixtures in to chemical components but cannot be used to separate compounds to simpler compounds.
Physical changes are always reversible using physical means and involve a change in the physical properties.Examples of physical changes include melting,boiling , change in texture, size,color,volume and density.Magnetism, crystallization, formation of alloys are all reversible and hence physical changes.
They involve only rearrangement of atoms and are often characterized to be changes which are reversible.
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The distance between two adjacent peaks on a wave is called the wavelength. (2pts) a. The wavelength of ultraviolet light is 255nm. What is the wavelength in meters? b. The wavelength of a beam of red light is 683nm. What is its wavelength in angstroms?
Answer:
a.2.55e-7
b.6830
Explanation:
A strand of DNA has the following string of bases:
TAACGTCG
What is the order of bases of the RNA molecule that is built from this DNA?
The genetic makeup of the majority of these organisms is either RNA or DNA. For instance, some viruses' genetic material may be RNA whereas others' genetic material may be DNA. RNA is present in the Human Immunodeficiency Virus (HIV), which after adhering to the host cell, transforms into DNA.
DNA is a collection of molecules that is in charge of transporting and passing genetic information from parents to children. A ribonucleic acid called RNA aids in the body's production of proteins. In the human body, new cells are created as a result of this nucleic acid.
Instead of thymine, uracil is present in RNA. All other bases are same as DNA like adenine, guanine and cytosine. The order of bases in RNA is:
UAACGUCG.
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