Answer:
A- Ca
B- Ca(OH)2
C-CaCO3
D- CaO
Explanation:
Element A is calcium. Calcium reacts with water to form calcium hydroxide (compound B) as follows; Ca(s) + 2H2O(l) ----> Ca(OH)2(s) + H2(g).
When exposed to air, calcium hydroxide (compound B) forms calcium trioxocarbonate IV (CaCO3) which is compound C as follows;
Ca(OH)2(s) + CO2(g) -----> CaCO3(s) + H2O(l)
On heating compound C, the oxide, CaO (D) is formed as follows;
CaCO3(s) ------> CaO(s) + CO2(g)
This oxide reacts with water to yield B again as follows;
CaO(s) + H2O(l) ----> Ca(OH)2(s)
A container initially holds 5.67 x 10^10-2 mol of propane and has a volume of V1. The volume of the container was increased by adding an additional 2.95 x 10^-2 mol of propane to the container, so that the container has a final volume of 1.93 L. If the temperature and pressure are constant, what was the initial volume of the container ,V1?
Answer:
The initial volume of the container was 1.27L
Explanation:
Avogadro's law states that under the same pressure and temperature, equal moles of gases occupies equal volume. The equation is:
V₁n₂ = V₂n₁
Where V is volume and n moles of 1, initial state and 2, final state.
In the problem, initial moles are 5.67x10⁻², final moles after the addition are:
5.67x10⁻² + 2.95x10⁻² = 8.62x10⁻² moles
And, after the addition, the volume is 1.93L.
Replacing in Avogadro's law:
V₁×8.62x10⁻² moles = 1.93L×5.67x10⁻² moles
V₁ = 1.27L
The initial volume of the container was 1.27LWhich of the following choices would have a negative entropy change? A. CaCO3(s)−>CaO(s)+CO2(g)
Answer: N2(g) + 3H2(g)- >2NH3(g) denotes a negative entropy change.
Explanation:
Entropy is defined as the extent of disorder in a system. The degree of entropy is more in a gas and less in a solid.
Here, 1st reaction produces ammonia from nitrogen and hydrogen. We can see that four moles of gases produces 2 moles of gaseous product. So the degree of disorder in the system is decreasing. So the entropy is also decreasing.
Easyyyyy plz ...................
Permanent hardness of water is caused by dissolved :-
A) CaCl
B) Ca(HCO3)2
C) Mg(HCO3)2
D) NaOH
Answer:
The answer is B
Explanation:
Answer:
Hello!
Your answer is B) Ca(HCO3)2!!
Explanation:
Hope this helps you!!
itsMATT04
:>
MARKING BRAINLIEST!! - Chlorine reacts with methane to form gaseous hydrogen chloride and chloromethane according to the following equation: Cl2 (g) + CH4 (g) → HCl (g) + CH3Cl (g) If 100 mL of chlorine reacted with excess methane at constant pressure and temperature, what volume of chloromethane would be formed? Question 7 options: 50, cannot tell from the information provided, 200, 100
Answer:
100mL of chloromethane
Explanation:
Based on the equation:
Cl₂(g) + CH₄(g) → HCl(g) + CH₃Cl(g)
1 mole of chlorine reacts per mole of methane to produce 1 mole of HCl and 1 mole of chloromethane
Avogadro's law says that equal volumes of all gases, at the same temperature and pressure, have the same number of molecules. Using Avogadro's law we can say of the equation that:
1 mL of chlorine reacts per mL of methane to produce 1 mL of HCl and 1 mL of chloromethane
Because the system stays under constant pressure and temperature.
As 100mL of Cl₂ reacts with excess of CH₄ and 1mL of Cl₂ produce 1mL of CH₃Cl there are produced:
100mL of chloromethaneHow many moles of ZnCl2 will be produced from 61.0 g of Zn, assuming HCl is excess?
Answer: 0.938 moles of [tex]ZnCl_2[/tex] will be produced.
Explanation:
To calculate the moles, we use the equation:
[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text {Molar mass}}[/tex]
moles of zinc:
[tex]\text{Number of moles}=\frac{61.0g}{65g/mol}=0.938moles[/tex]
[tex]Zn+2HCl\rightarrow ZnCl_2+H_2[/tex]
As HCl is in excess , zinc is the limiting reagent and it limits the formation of product.
According to stoichiometry :
1 mole of Zn produce = 1 mole of [tex]ZnCl_2[/tex]
Thus moles of Zn produce = [tex]\frac{1}{1}\times 0.938=0.938[/tex] moles of [tex]ZnCl_2[/tex]
Thus 0.938 moles of [tex]ZnCl_2[/tex] will be produced.
Which metal will react spontaneously with Cu2+ (aq) at 25°C?
Hg
Mg
Ag
Au
Answer:
Mg
Explanation:
The standard reduction potentials are
E°/V
Au³⁺(aq ) + 3e⁻ ⟶ Au(s); 1.42
Hg²⁺(aq) + 2e⁻ ⟶ Hg(l); 0.85
Ag⁺(aq) + e⁻ ⟶ Ag(s); 0.80
Cu²⁺(aq) + 2e⁻ ⟶ Cu(s); 0.34
Mg2+(aq) + 2e- ⟶ Mg(s); -2.38
The more negative the standard reduction potential, the stronger the metal is as a reducing agent.
Mg is the only metal with a standard reduction potential lower than that of Cu, so
Only Mg will react spontaneously with Cu²⁺.
Answer:
B. Mg
Explanation:
When the name of ions end with ide, is it true that they are all negative ions
You are given a mixture of sand, sugar and sulphur. Give the method you will use to separate the three constituents. ___________
Answer:
1:put these in sneaker and add water since sulphur is insoluble and the sugar will dissolve and the sand will settle obtain the sulphur
2:filter the mixture of sand and sugar solution to obtain the sand as residue and solution as filtrate
3:using an evaporating dish evaporate sugar solution to saturation not dryness to get crystals.
Select the correct answer.
What is the reason for heat transfer from one substance to another
Answer:
Difference in temperature.
Explanation:
Conduction is the movement of heat energy through a substance or from one substance to another by direct contact of atoms and molecules. Heat moves directly from one molecule to another. The heat energy speeds up the movement of the atoms and they collide with other molecules setting them into faster motion.
Label the following as either an Element, Compound, or Mixture.
Answer:
27. Element (Because it contains all same atoms)
28. Compound (It contains atoms held together through chemical bonds)
29. Element (it contains all same atoms)
33. Mixture (It contains different atoms but they are not held together through chemical means)
34. Compound (Different atoms held together through chemical means)
35. Mixture (Mixture of elements and compounds)
30. Element (it contains all same atoms)
31. Mixture (Mixture of elements and compounds)
32. Element (Contain all same atoms although held together through chemical means they are not compounds)
For which of the following reactions will a decrease in pressure shift the equilibrium to the left?
A). 2A2 (g) + B2 (g) --> 2A2B (g)
B). 2AB (g) --> A2 (g)+ B2 (g)
C). 2A2F3 (g) --> 4A (g) + 3F2 (g)
D). 2B (s) + 2HA (aq) --> 2BA (aq) + H2 (g)
Answer: I just took the test, the answer is A.
Explanation:
Describe the crystallization process as applied in salt preparation
Explanation:
The principle used in the preparation of these salts is to dissolve
the cystine in an alcoholic alkali solution to which just sufficient
water to effect solution has been added, and, after filtering from
excess cystine, to precipitate the salt by addition of a suitable
indifferent solvent. While various solvents, such as acetone,
ether, or large amounts of alcohol caused precipitations, these were
either oily or amorphous. Only acetonitrile was found to possess
the power of initiating regular crystallization in the salt solutions.
While the solutions of the different salts require different amounts
of the solvent for complete precipitation, a partial substitution of
absolute ether for acetonitrile was found expedient in the case
of the most soluble of the salts, the K salt.
Answer:
It is simply a process of forming crystal.
Explanation: When salt is heated and dissolve in the liquid mainly water then its called saturated solution. When we further add salt and increase heat in order to dissolve it then it forcibly dissolve in liquid it's called supersaturated solution. After we slowly cool down the temperature then the salt we have put in supersaturated solution arises in the form of crystal. Hence its called crystalization.
For a system, H2(g) + I2(g) ⇌ 2 HI(g), Kc = 62.9 at 750 K. 2.80 moles of HI were placed in a 10.0-liter container, brought up to 750 K, and allowed to come to equilibrium. Which situation described below is true, at equilibrium?
a. [HI] = 2 × [H2]
b. [HI] = [H2]
c. [HI] < [H2]
d. [HI] > [H2]
e. [H2] > [I2]
Answer:
d. [HI] > [H2]
Explanation:
The explanation at equilibrium is shown below:-
Data provided [tex]H_2(g) + I(g) \rightleftharpoons 2HI_(g)[/tex]
Initial concentration - - [tex]\frac{2.80}{10}[/tex] = 0.280 M
At equilibrium x x 0.280 - 2x
[tex]K_c = \frac{(HI)^2}{(H_2)(I_2)} = 62.9[/tex]
[tex]= \frac{(0.280 - 2x)^2}{x^2} = 62.9\\\\4x^2 - 1.12x + 0.0784 = 62.9x^2[/tex]
After solve the above equation we will get
x = 0.0282 M
Therefore at equilibrium
[tex][H_2] = [I_2] = x = 0.0282M\\\\[/tex]
[tex][HI] = 0.280 - 2x = 0.2236 M[/tex]
Hence, the correct option is d.
Below are 5 sets of potential solutes for you to compare. Both members of each pair are very soluble in water. If you had equal molar concentrations of each solution, which member of each pair would theoretically be the better conductor of electricity?
A. CsCl, CaCl2.
B. CaS, Li2S.
C. KBr, AlCl3.
D. AlCl3, MgC2.
E. KI, K2S.
Answer:
Option D. AlCl₃, MgC₂
Explanation:
We need to dissociate all the salts, to determine the i. (Van't Hoff factor).
The salt who has the highest value, will be the better conductor of electricity
CsCl → Cs⁺ + Cl⁻ i = 2
CaCl → Ca²⁺ + Cl⁻ i = 2
CaS → Ca²⁺ + S⁻² i = 2
Li₂S → 2Li⁺ + S⁻² i = 3
KBr → K⁺ + Br⁻ i = 2
AlCl₃ → Al³⁺ + 3Cl⁻ i = 4
MgC₂ → Mg²⁺ + 2C⁻ i = 3
KI → K⁺ + I⁻ i = 2
K₂S → 2K⁺ + S⁻² i = 3
The biggest i, is in pair D.
Answer:
Look at the Screenshot!!!
Explanation:
Got it right on Odessyware ;) Have a nice day!!!!!
Which type of river is similar to a mature river, but flows more slowly so has less power to change the landscape? Select one: a. Youthful River b. Mature River c. Old Age River
Answer:
The correct option is;
C. Old Age River
Explanation:
Among the three stages of the development of a river, which are the youthful, mature, and old age stages, the old age river is least dynamic
The water is very slow moving with a low gradient and lesser erosive power to alter the landscape which results in the appearance of flood planes
Examples of old age rivers include, lower Ganges, lower Nile, Indus, and Yellow rivers
Old age rivers are characterized by a broad shape, with a wide flood plane, a very gentle gradient and the water current is low.
Answer:c
Explanation:
old age river
How would you measure the mass and weight of an object?
Answer:
Weight = mass × earth's gravitational acceleration
Explanation:
Follow the following steps to measure the mass and weight of an object:
Measure the mass of the object using an accurate measuring scale.Multiply the mass of that object with earth's gravitational acceleration which is approximately 9.8 N/kgWhat letter represents the enthalpy of reaction?
Answer:
Option D. T
Explanation:
Enthalpy change (ΔH) is simply the difference between the heat content of the product (Hp) and the heat content of the reactant (Hr). Mathematically, it is expressed as:
Enthalpy change (ΔH) = Heat of product (Hp) – heat of reactant (Hr)
ΔH = Hp – Hr
From the diagram given above, the difference between the heat content of product and the heat content of reactant is T.
Therefore, the enthalpy change of the reaction is T.
Why are the oxidation and reduction half-reactions separated in an
electrochemical cell?
Answer:
Electrochemical cells typically consist of two half-cells. The half-cells separate the oxidation half-reaction from the reduction half-reaction and make it possible for current to flow through an external wire.
Explanation:
A 25.0 mL sample of a solution of an unknown compound is titrated with a 0.115 M NaOH solution. The titration curve above was obtained with pH at equivalence point of around 8. The unknown compound is ________.
Answer:
Weak acid
Explanation:
A titration curve is a graphical description of the change in pH of the solution in the conical flask as the reagent is added from the burette. A titration curve can be plotted for the different kinds of acid and base titrations. The volume of the titrant is always plotted as the independent variable and the pH of the solution as the dependent variable. The equivalence point is read off from the titration curve. A titration curve is very important because it shows the pH at various points during the titration.
A weak acid/strong base titration leads to an equivalence point above 7. From the question, we were told that the pH at equivalence point lies around 8. Hence the unknown substance must be a weak acid.
Which of the following may suggest a catalyst has been used in a reaction, given the energy diagram for the same reaction without a catalyst?
A 35 gram of saturated solution is distilled out completely. If the solubility of the solute is 110, find the amount of residue solute snd distilled water
Answer:
3850g
Explanation:
Solubility is the amount of solute dissolved in a solvent.
Solubility is mass of solute÷mass of solvent
The solvent is 35grams
Solute?
Solubility of solute is 110
110=x/35
= 110 × 35
The amount of residue solute is 3850g
Which of the following would NOT be a conversion factor for mole to mole calculations for the following reaction: 2Al + 3Cl2 --> 2AlCl3
A: 3 mol Cl2 3 mol Al
B: 2 mol Al 3 mol Cl2
C: 2 mol AlCl3 2 mol Al
D: 3 mole Cl2 2 mol AlCl3
Answer: A. 3 mol [tex]Cl_2[/tex] 3 mol Al:
Explanation:
Te given balanced chemical equation is :
[tex]2Al+3Cl_2\rightarrow 2AlCl_3[/tex]
According to the stochiometry :
A: 3 mol [tex]Cl_2[/tex] 3 mol Al:
3 moles of chlorine reacts with 2 moles of aluminium
B. 2 mol [tex]Al[/tex] 3 mol [tex]Cl_2[/tex]:
2 moles of aluminium reacts with 3 moles of chlorine
C. 2 mol [tex]AlCl_3[/tex] 2 mol Al
2 mol of aluminium produces 2 mol of [tex]AlCl_3[/tex]
D. 3 mol [tex]Cl_2[/tex] 2 mol [tex]AlCl_3[/tex]
3 moles of chlorine produces with 2 moles of [tex]AlCl_3[/tex]
Thus the conversion factor not used for mole to mole calculations is 3 mol [tex]Cl_2[/tex] 3 mol Al:
The temperature of a sample of liquid water changes from 50°C to 30°C. Which statement best explains the change
that must happen at the molecular level?
ОООО
The molecules move more quickly and their average kinetic energy increases.
The molecules move more slowly and their average kinetic energy decreases.
The molecules move more quickly and their average kinetic energy decreases.
The molecules move more slowly and their average kinetic energy increases.
Answer:
The molecules move more slowly and their average kinetic energy decreases
Explanation:
The increased temperature meant that the atoms in liquid had a greater average energy of motion so as the temperature decreases the reaction would be inverse.
The branch of science which deals with the chemicals bond is called chemistry.
The correct option is B.
The energy which is produced by the motion of the particles is called kinetic energy. Temperature increases the motion of the particles. So, the kinetic energy increases when the temperature rises.
According to the question, the temperature of the water decreases therefore the kinetic energy decreases.
Hence, the correct option is B that is the molecules move more slowly and their average kinetic energy decreases.
For more information, refer to the link:-
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g When a 2.75g sample of liquid octane (C8H18) is burned in a bomb calorimeter, the temperature of the calorimeter rises from 22.0 °C to 41.5 °C. The heat capacity of the calorimeter, measured in a separate experiment, is 6.18 kJ/°C. Determine the ΔE for octane combustion in units of kJ/mol octane.
Answer:
The correct answer is 5021.25 kJ/mol octane
Explanation:
The heat absorbed by the calorimeter is given by:
heat absorbed = Ccal x ΔT
Given:
Ccal = 6.18 kJ/ºC (heat capacity of calorimeter)
ΔT= Final temperature - initial temperature = 41.5ºC-22.0ºC = 19.5ºC
We first calculate the heat absorbed:
heat absorbed = 6.18 kJ/ºC x 19.5ºC = 120.51 kJ
The change in internal energy (ΔE) is equal to the heat absorbed by the calorimeter. In order to determine ΔE in kJ/mol we have to divide the heat into the number of moles of octane (C₈H₁₈) burned in the calorimeter.
Molecular weight (C₈H₁₈) = (12 g/mol x 8) + (1 g/mol x 18) = 114 g/mol
Moles of C₈H₁₈= mass/molecular weight= (2.75 g)/(114 g/mol)= 0.024 moles
Finally, we calculate ΔE:
ΔE = heat absorbed/moles of octane = (120.51 kJ)/(0.024 mol octane) = 5021.25 kJ/mol octane
Ascorbic Acid is a organic compound with formula C6H8O6, originally called Hexuronic Acid. It's a white solid, but impure samples can be yellowish. It dissolves well in water to give mildly acidic solutions. It is a mild reducing agent.
What is the other name of Ascorbic Acid?
Explanation:
ascorbic acid is lemon
lemon contain ascorbic acid....
it is organic acid.....
Seawater is highly saline, which means it contains large amounts of dissolved salt. When seawater freezes and icebergs form, the water in the iceberg doesn’t take the salt with it. What effect will this phenomenon have on the concentration of salt in the water around the iceberg?
Answer:
Because the amount of liquid water decreases and the amount of dissolved salt remains constant, the concentration of salt in the liquid water around the iceberg will increase.
Explanation:
Answer:
Because the amount of liquid water decreases and the amount of dissolved salt remains constant, the concentration of salt in the liquid water around the iceberg will increase.
Explanation:
PLATO exact answer
The freezing point of pure chloroform is -63.5°C, and its freezing point depression constant is 4.07°C•kg/mol. If the freezing point of a solution of benzoic acid in chloroform is -70.55°C, what is the molality of this solution? 0.58 m 1.7 m 16 m 17 m
Answer: The molality of this solution is 1.7 m
Explanation:
Depression in freezing point:
[tex]T_f^0-T^f=i\times k_f\times m[/tex]
where,
[tex]T_f[/tex] = freezing point of solution = [tex]-70.55^0C[/tex]
[tex]T_f^0[/tex] = freezing point of pure chloroform = [tex]-63.5^0C[/tex]
[tex]k_f[/tex] = freezing point constant of benzene = [tex]4.07^0Ckg/mol[/tex]
m = molality
i = Van't Hoff factor = 1 (for non-electrolyte)
[tex]-63.5-(-70.55)^0C=1\times 4.07^0Ckg/mol\times m[/tex]
[tex]7.05=1\times 4.07^0Ckg/mol\times m[/tex]
[tex]m=1.7[/tex]
Thus the molality of this solution is 1.7 m
Two oxides of lead were separately reduced to metallic lead by heating in a current of
i) Mass of yellow oxide taken=3.45g
ii) Mass of brown oxide taken=1.227g
Loss in mass during reduction=16g
Show that the above data illustrate the law of multiple proportions.
Answer:
HeyA ❤
Let us consider the mass of oxygen as 1 g.
Mass of lead obtained from yellow oxide = 3.45 g – 0.24 g = 3.21 g
Mass of oxygen = 0.24 g
The mass of lead that combines with 0.24 g of oxygen = 3.21 g
Therefore, mass of lead that combines with 1 g of oxygen = 3.21/ 0.24 = 13.4 g
Mass of lead obtained from brown oxide = 1.227 g – 0.16 g = 1.067
Mass of oxygen = 0.16g
The mass of lead that combines with 0.16 g of oxygen = 1.067 g
Therefore, mass of lead that combines with 1 g of oxygen = 1.067/ 0.16 = 6.66 g
Now, ratio of masses of lead which combines with a fixed mass of oxygen = 13.4 : 6.66
= 2 :1
Thus, masses of lead which combine with the fixed mass of oxygen are in the ratio of (2:1) i.e. small whole numbers.
Hence, the law of multiple proportions is illustrated.
Follow meehhhh Piper ❤
show bond formation in magnesium chloride
mg has a 2 in its valence shell
it will become mgcl2
. . . .
: Cl -------- Mg ------ Cl :
. . . .
Which statement accurately describes a light-year
Answer:
B. distance light travels in a year
got it on edge :)
The statement which accurately and best describes a light-year is the total distance which light travels in a complete year
What is velocity of light?Velocity of light can simply be defined as that fundamental constant that represents the speed of electromagnetic radiation in a vacuum.
The velocity of light = 2.9979 × 10^10cm/s
So therefore, the statement which accurately and best describes a light-year is the distance which light travels in a complete year
Learn more about light-year:
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