Answer:
A.
Explanation:
Higher temperature - more kinetic energy - more space between particles - higher volume.
A. If both Assertion & Reason are true and the reason is the correct explanation of the assertion. B. If both Assertion & Reason are true but the reason is not the correct explanation of the assertion. C. If Assertion is true statement but Reason is false. D. If Assertion is false and Reason is true Assertion: .Formation of soluble products from insoluble ones is called precipitation. Reason : Precipitation involves formation of insoluble products from soluble ones
Answer:
D- Assertion is false and Reason is true
Explanation:
Precipitation is said to have occurred when an insoluble product is formed from soluble ones. Let us take an instance;
BaCl2(aq) + H2SO4(aq) -------> BaSO4(s) + 2HCl(aq)
The barium sulphate so formed is an insoluble product obtained from the reaction of soluble barium chloride and sulphuric acid. This is a typical example of a double replacement reaction as the both ions exchanged partners.
Thus, the assertion is false but the reason is true.
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.
A container initially holds 5.67 x 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 if 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?
Answer:
Initial volume of the container (V1) = 1.27 L (Approx)
Explanation:
Given:
Number of mol (n1) = 5.67 x 10⁻²
Number of mol (n2) = (5.67 +2.95) x 10⁻² = 8.62 x 10⁻²
New volume (V2) = 1.93 L
Find:
Initial volume of the container (V1)
Computation:
Using Avogadro's law
V1 / n1 = V2 / n2
V1 / 5.67 x 10⁻² = 1.93 / 8.62 x 10⁻²
V1 = 10.9431 / 8.62
Initial volume of the container (V1) = 1.2695
Initial volume of the container (V1) = 1.27 L (Approx)
Answer: 1.27 L
Explanation:
First, calculate the final number of moles of propane (n2) in the container.
n2 = n1 + nadded = 5.67 × 10^−2 mol + 2.95 × 10^−2 mol = 8.62 × 10^−2 mol
Rearrange Avogadro's law to solve for V1.
V1 = V2 × n1 / n2
Substitute the known values of n1, n2, and V2,
V1 = 1.93 L × 5.67 × 10^−2 mol / 8.62 × 10^−2 mol = 1.27 L
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
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.
How many significant figures are there in 6.07x10^-15?
Answer:
3
Explanation:
6.07 has 3 digits and all are significant
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)
Na-23 has 12 neutrons. What is it’s atomic number?
Answer:
11 Protons
Explanation:
Na-23 shows the mass of the element as 23. Therefore subtract 12 neutrons from the mass to get # of protons which is = to atomic #.
The atomic number of 23-Na is 11. It can be calculated from the number of protons present in the nucleus of an atom.
The atomic number is a fundamental property of an element and represents the number of protons found in the nucleus of an atom. It uniquely identifies each element on the periodic table. In a neutral atom, the atomic number also indicates the number of electrons present in the atom, as the number of protons and electrons in an atom are equal.
For example, hydrogen has an atomic number of 1, indicating that it has one proton in its nucleus. Oxygen has an atomic number of 8, indicating that it has eight protons in its nucleus.
The atomic number determines the element's position in the periodic table and provides important information about its properties and behavior.
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If the external vapor pressure is 2.0 atm , what is the vapor pressure of the water at its boiling point?
Answer:
22
Explanation:
22
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?
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
How many moles are in 10.23 g of PO4-3? How many moles are 8.25 x 10^28 molecules of Na2CO3? What is the mass of 6 moles of CH2O? How many formula units are in 6.34 g of NaCl? How many ions are in 0.25 moles of Cu+2? How many grams are in 3.4 x 10^24 molecules of CH4? How many moles are in 10 mL of water (density of water = 1 g/mL)? (sorry for so many questions in one)
Answer:
1) 0.1077 moles
2) 137043.2 moles
3) 180.186 grams
4) 6.53×10²² molecules or formula units
5) 1.505×10²³ ions
6) 90.626 grams
7) 0.555 moles
Explanation:
1) The number of moles, n = Mass of the substance/(Molar mass of the substance)
The molar weight of PO₄⁻³ is 94.971 g/mol
The number of moles in 10.23 g of PO₄⁻³ is n =10.23/94.971 = 0.1077 moles
The number of moles in 10.23 g of PO₄⁻³ = 0.1077 moles
2) The number of molecules of Na₂CO₃ in one mole of Na₂CO₃ is given by the Avogadro's number, [tex]N_A[/tex] = 6.02 × 10²³ molecules
Therefore, the number of moles in 8.25 × 10²⁸ molecules of Na₂CO₃ is found by determining how many Avogadro's number of molecules are in 8.25 × 10²⁸ molecules of Na₂CO₃ as follows;
The number of moles in 8.25 × 10²⁸ molecules of Na₂CO₃ = (8.25 × 10²⁸)/(6.02 × 10²³) = 137043.2 moles
The number of moles in 8.25 × 10²⁸ molecules of Na₂CO₃ = 137043.2 moles
3) The molar mass of CH₂O = 30.031 g/mol
Therefore, the mass of 6 of CH₂O = 6 moles × 30.031 g/mol = 180.186 grams
The mass of 6 of CH₂O = 180.186 grams
4) The molar mass of NaCl = 58.44 g/mol
The number of moles of NaCl in 6.34 g of NaCl 6.34/58.44 = 0.1085 moles
1 formula unit of NaCl = 1 molecule of NaCl
The number of molecules in one mole of a substance = [tex]N_A[/tex] = 6.02 × 10²³
Therefore, the number of molecules in 0.1085 moles of NaCl = 6.02 × 10^(23) × 0.1085 = 6.53×10²² molecules or formula units
5) The number of ions per mole of any substance is give by Avogadro's number, [tex]N_A[/tex] = 6.02 × 10²³ ions,
The number of ions in 0.25 moles of Cu⁺² = 0.25×6.02 × 10²³ ions = 1.505×10²³ ions
The number of ions in 0.25 moles of Cu⁺² = 1.505×10²³ ions
6) The molar mass of CH₄ = 16.04 g/mol
The number of moles, n, in 3.4×10²⁴ = 3.4×10^(24)/(6.02×10^(23)) = 5.65 moles 5.65*16.04
The mass of 5.65 moles of CH₄ = 5.65 moles × 16.04 g/mol = 90.626 grams
The mass of 3.4×10²⁴ molecules of CH₄ = 90.626 grams
7) The density of water = 1 g/mL
The volume of the water 10 mL
The mass of the water = Volume × Density = 10 mL × 1 g/mL= 10 grams
The molar mass of water = 18.015 g/mol
The number of moles of water in 10 g of water = mass/(Molar mass) = 10/18.015 = 0.555 moles.
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.
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What 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.
How many atoms are in 10g of Al
Answer:
2.22 x 10²³
Explanation:
number of atoms = mole x 6 x 10²³first we have to find number of moles
moles = mass(g) / molar mass (Mr) (g/mol)mol = 10/27
mol= 0.37 mol
Now,
number of atoms = mole x 6 x 10²³
= 0.37 x 6 x 10²³
= 2.22 x 10²³
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.....
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
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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
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 chloromethaneFor 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.
What is the unit charge on each subatomic particles
Answer:
Protons, Electrons, Neutrons
Explanation:
Neutron: 0 or Neutral
Electron: -1 or Negative
Proton: +1 or Positive
For proton and neutron look at neutr for neutral and p for positive
Answer:
❤️❤️❤️❤️❤️❤️❤️❤️❤️❤️❤️❤️❤️❤️❤️
The answer is Protons, Electrons, Neutrons
There is three of them.....
Hope this will help you
❤️❤️❤️❤️❤️❤️❤️❤️❤️❤️❤️❤️❤️❤️❤️
Explanation:
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:
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!!!!!
Si el elemento "X" tiene 8 protones y el elemento "Y" tiene 11 protones, al reaccionar ¿Qué tipo de enlace pueden formar? Seleccione una: a. Metálico. b. Covalente puro. c. Covalente polar. d. Iónico.
Answer:
D; Iónico
Explanation:
El elemento con 8 protones es oxígeno, mientras que el elemento con 11 protones es sodio.
El sodio es un metal alcalinotérreo, mientras que el oxígeno no es un metal.
En general, cuando tenemos un elemento metálico como el sodio, que se une con uno no metálico como el oxígeno, el tipo de enlace formado como resultado de la transferencia completa de electrones desde la capa de valencia del sodio a la capa de valencia del oxígeno para completar su propia configuración de octeto se denomina enlace electrovalente o, más generalmente, enlace iónico
Which 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.
Which event is most likely occurring? diffusion because particles move from regions of high concentration to regions of low concentration diffusion because particles move from regions of low concentration to regions of high concentration effusion because there is a movement of a gas through a small opening into a larger volume effusion because there is a movement of a gas through a large opening into a smaller volume
Answer: c
Explanation: effusion because there is a movement of a gas through a small opening into a larger volume
pls help...
You are a forensic scientist working on a murder case. You have taken the blood sample from the crime scene and put it through Electrophoresis and Southern blotting. What step do you need to take next? A. Add ethanol B. Add restriction enzymes C. Add minisatellites D. Add radioactive probes
Add minisatellites. Hence, option C is correct.
What is Electrophoresis?Electrophoresis is a laboratory technique used to separate DNA, RNA or protein molecules based on their size and electrical charge.
You are a forensic scientist working on a murder case. You have taken the blood sample from the crime scene and put it through Electrophoresis and Southern blotting. you need to add minisatellites.
Hence, option C is correct.
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How 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.
Based on my previous question I have posted.. Answer this.. It's the continuation
Table 7.3 is different
Answer:
We don't know what solvent X and solvent Y are, but from the chart, we can see that in solvent X, hydrochloric acid can conduct electricity (bulb lights up), and react with calcium carbonate.
So, we can say the electrical conductivity when HCl is dissolved in solvent X is high, and when HCl is dissolved in solvent Y, the electrical conductivity is low (because light bulb doesn't light up).
Additionally, in solvent X, HCl ionizes, this shows the property of acids: reacts with carbonates to give CO2 (because CO2 reacts with lime water to make it cloudy).
In solvent Y, HCl does not ionize, so there is no reaction between acid and calcium carbonate.
The volume of a sample of pure HCl gas was 221 mL at 20°C and 111 mmHg. It was completely dissolved in about 50 mL of water and titrated with an NaOH solution; 18.7 mL of the NaOH solution was required to neutralize the HCl. Calculate the molarity of the NaOH solution.
Answer:
[tex]molarity =6.9\times 10^{-3}\ M\\[/tex]
Explanation:
We know that , the reaction of HCl and NaOH is given as follows
[tex]NaOH+HCl=NaCl +H_2O[/tex]
Given that
Pressure = 111 mm Hg
[tex]P=111\times 13.6\times 10^{-3}\times 9.81\times 1000=14.809\ kPa[/tex]
Temperature = 20°C
T=20+273=293 K
Volume= 221 m L
V=0.221 L
Number of moles of HCl is given as follows
[tex]n=\dfrac{P\times V}{R\times T}\\n=\dfrac{0.148\times 0.221}{0.821\times 293}=1.3\times 10^{-4}\ moles[/tex]
From the above reaction we can say that
Number of moles of HCl=Number of moles of NaOH
Volume of NaoH is given as follows
V=18.7 = 0.0187 L
Therefore molarity
[tex]molarity =\dfrac{n}{V_{NaOH}}\\molarity =\dfrac{1.3\times 10^{-4}}{0.0187}=6.9\times 10^{-3}\ M\\molarity =6.9\times 10^{-3}\ M\\[/tex]