Answer:
The solubility of KCl is 1.93 mol/dm³
Explanation:
The information given are;
The mass of the potassium chloride, KCl = 144 g
The volume of the water solvent = 1000 cm³ = 1 dm³
The temperature of the solvent = 90 °C
The atomic mass of potassium, K = 39 u
The atomic mass of chlorine, Cl = 35.5 u
The number of moles of potassium in one mole of potassium chloride, KCl = 1 mole
The number of moles of chlorine in one mole of potassium chloride, KCl = 1 mole
The molar mass of the potassium chloride = 39 + 35.5 = 74.5 g/mol
The number of moles, n, of potassium chloride, KCl in 144 g of potassium chloride, KCl is given as follows
n = Mass/(Molar mass) = 144/74.5 = 1.93 moles
1.93 moles will dissolve in 1 dm³
Therefore, the solubility of KCl is 1.93 mol/dm³.
what happens when ca no3 2 is heating it gives CaO ,NO2 and 02
Answer:
balanced equation:
2Ca(NO3)2 (aq)-----> 2CaO (s) + 4NO2 (g) + O2 (g)
So heating 2 moles of Ca(NO3)2 gives 2 moles of CaO, 4 moles of NO2 and 1 mole of O2. This is a heat decomposition reaction. It gives a white precipitate (CaO), and brown pungent gas (NO2).
Answer:
The balanced equation of the reaction is below.
Explanation:
2Ca(NO3)2 -----> 2CaO + 4NO2 + O2.
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
answer the question briefly: How can atom collapse and why are atoms stable?
The nuclei of atoms become unstable when the repelling forces of the protons cannot be balanced by the number of neutrons in the nucleus. It then re-arranges itself randomly to a more stable configuration by emitting any of a series of particles. During radioactive decay, an atom does not collapse.
Since an atom is mostly empty space - that is it’s nucleus is relatively distant from the electron shells so, in the presence of extreme forces such as gravity inthe collapse of a large star, the inward pressures on the atom overcome the natural balance of the atomic structure and the ‘empty space’ disappears as nuclei are mashed together by the intense pressures and a neutron star is formed. Under even more external pressure, even the neutron star can collapse to form a black hole.
Question 1 of 10
Which two terms apply to oceanic crust rather than continental crust?
A. Thicker
O B. Lighter in color
0 C. Denser
I D. Younger in age
The two terms apply to oceanic crust rather than continental crust C. Denser and D. Younger in age
What is the oceanic crust made up of?
Oceanic Crust Oceanic crust, extending 5-10 kilometers (3-6 kilometers) beneath the ocean floor, is mostly composed of different types of basalts. Geologists often refer to the rocks of the oceanic crust as “sima.” Sima stands for silicate and magnesium, the most abundant minerals in oceanic crust.
What is an example of oceanic crust?Oceanic crust is thin (6 km thick) and dense (about 3.3 g/cm), consisting of basalt, gabbro, and peridotite. They include oceanic sediments (e.g. radiolarites, turbidites) and oceanic crust (e.g. basalt, pillow lava).
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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?
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]
Which of the following elements does not lose an electron easily? NA F MG AL
Answer:
F
EXPLANATION
Among the given elements fluorine(F)can not lose electrons easily because of its high electron affinity, high nuclear charge and high electronegativity.
Answer:
F
Explanation:
it won't lose electron , rather it would gain electron to complete its octate......
Electronic Configuration of F = 2,7
So F will gain 1 electron ....
If a had a number that was 12.47, what would be the answer rounded to 2 sig figs?
12
Explanation:
Look at the number directly after the number you want to keep. I'm your case you want to keep the first two numbers and the number directly after is 4 so there is no need to round up. Keep your 12 without a decimal.
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
List four examples of diffusion seen in daily life.
Answer:
Spraying perfume in one corner of the room and the smell travels to the other side of the room
Explanation:
Describe how red shifts were used by cosmologists to determine that the universe was expanding. How
is this evidence for the big bang theory?
Explanation:
astronomers have discover that in general the future of a Galaxy is, the more redshift light is this mean that the further away the Galaxy are the faster they are moving this is similar to explosion where the bits moving fastest travel for furthest on the explosion redshift data provides evidence that the universe including space itself is expanding .
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)
An ionic bond is the attraction between _____.
Answer:
oppositely charged ions in a chemical compound
Explanation:
Answer:
Between ions
Explanation:
what kind of a compounds act as an electrolyte? explain with and example
Answer:
ionic compounds
Explanation:
just finished ap chem
Answer:
An ionic compound can act as an electrolyte. This is because an electrolyte should allow charges to travel inside it.
e.g = H2SO4, NaCl
Explanation:
Triangle DEF is congruent to TriangleD'EF' by the SSS theorem. Which single rigid transformation is required to map TriangleDEF onto TriangleD'EF'? dilation reflection rotation translation
Answer:
B. reflection
Explanation:
Rigid transformations are methods involved in changing the dimensions or orientation of a given figure. The methods are; dilation, rotation, translation and reflection.
Reflection is the process in which a given figure is turned or flipped with respect to a point or line of reference.
In the given question,
ΔDEF ≅ ΔD'EF' (Side-Side-Side congruence property)
This implies that ΔDEF was reflected about point E to produce ΔD'EF'. Thus the required rigid transformation is reflection.
Answer:
Is C - Rotation
Explanation:
I have right on my test
What is the precipitate in the following reaction?
2AgNO3(aq) + Na2S(aq) → Ag2S(s) + 2NaNO3(aq)
Answer:
2Ag(+1)(aq) + S(-2)(aq) --> Ag2(+1)S(-2)(aq)
Explanation:
The final equation is
2Ag(+1)(aq) + S(-2)(aq) --> Ag2(+1)S(-2)(aq)
2Ag(+1)NO3(-1)(aq) + Na2(+1)S(-2)(aq) --> Ag2(+1)S(-2)(s) + 2Na(+1)NO3(-1)(aq)
AgNO3, Na2S, and NaNO3 are all strong electrolytes, so we immediately separate those, making the new equation:
2Ag(+1)(aq) + 2NO3(-1)(aq) + 2Na(+1)(aq) + S(-2)(aq) --> Ag2(+1)S(-2)(s) + 2Na(+1)(aq) + 2NO3(-1)(aq)
After that, you cancel out all the ions that appear more than once, which in this case would leave us with a final equation of...
2Ag(+1)(aq) + S(-2)(aq) --> Ag2(+1)S(-2)(aq)
Answer:
Explanation:
C
calculate the mass of sodium sulphate required to prepare its 20%of solution in 100 g ofwater
Answer:
25 g
Explanation:
Mass percent implies the mass of solute dissolved in a solution
Mass percent = mass of solute/mass of solute + mass of solvent × 100/1
Since mass percent concentration= 20%
Mass of solvent = 100g
Let mass of solute = x
Hence;
20 = x/x +100 ×100/1
20/100= x/x + 100
0.2 = x/x + 100
0.2(x + 100) = x
0.2x + 20 = x
20 = x - 0.2x
20 = 0.8x
x= 20/0.8
x= 25 g
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:
In calculating the equilibrium constant for a reaction, the coefficients of the chemical equation are used as exponents for the factors in the equilibrium expression. TRUE FALSE
Answer: The given statement is TRUE.
Explanation:
An equilibrium reaction is one in which rate of forward reaction is equal to the rate of backward reaction.
Equilibrium constant is defined as the ratio of the product of the concentration of products to the product of the concentration of reactants each raised to their stochiometric coefficient.
For example for the given equilibrium reaction;
[tex]2H_2O(g)\leftrightharpoons 2H_2(g)+O_2(g)[/tex]
[tex]K_{eq}=\frac{[H_2]^2[O_2]}{[H_2O]^2}[/tex]
Thus the given statement that in calculating the equilibrium constant for a reaction, the coefficients of the chemical equation are used as exponents for the factors in the equilibrium expression is True.
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
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
how to make a salt by neutralization reaction
Answer:
Acid+Base=Salt+water
This is the formula of neutralization reaction.
According to this formula you can make salts by reacting an acid with a base.
Hope this helps ❤❤❤.
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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The intake stroke of a positive displacement compressor is most similar to that of a
A. thermostatic expansion valve.
B. auxillary electric water pump.
C. one-stroke variable displacement compressor.
D. two-stroke cylinder engine.
Answer:
D. two-stroke cylinder engine.
Explanation:
Two-stroke cylinder engine: In chemistry, the term "two-stroke cylinder engine" is described as one of the types of "internal combustion engine" that tends to complete a single "power cycle" possessing two different strokes of the "piston" during a particular "crankshaft revolution".
It generally consists of two different strokes that are being often known as power or exhaust and suction stroke.
In the question above, the given statement signifies the "two-stroke cylinder engine".
A sample of O2 gas is collected over water at 25oC at a barometric pressure of 751 torr. The vapor pressure of water at 25oC is 23.8 torr. What is the partial pressure of the O2 gas in the sample
Answer:
727.7 torr
Explanation:
Since the gas was collected over water, it is likely to be saturated with water vapour and the total pressure is given as;
Ptotal = Pgas + Pwater
From the question;
Ptotal = 751 torr
Pgas = ?
Pwater = 23.8 torr
Making Pgas subject of equation, we have;
Pgas = Ptotal - Pwater
Pgas = 751 torr - 23.8 torr
Pgas = 727.7 torr
how many sigma and pi bonds in propionic bond
Which of the following is represented by the number of significant figures in a quantity? A) estimation B) precision C) accuracy D) scientific notation
Answer: the answer is B estimation
Explanation:
i just took a test
The one that is represented by the number of significant figures in a quantity is scientific notation. The correct option is D.
What is scientific notation?Scientific notation is a method of expressing numbers that are either too large or too small to be written in decimal form.
In the United Kingdom, it is known as scientific form, standard index form, or standard form.
The proper scientific notation format is an x 10b, where an is a number or decimal number with an absolute value greater than or equal to one and less than ten, or 1 |a| 10. b is the power of ten required for scientific notation to be mathematically equivalent to the original number.
Scientific notation is represented by the number of significant figures in a number.
Thus, the correct option is D.
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------------neutral particles in an atom
Answer:
neutrons :
Explanation:
Protons are positively charged, while electrons are negatively charged. Neutrons are electrically neutral, as the name suggests. The electric charge, noted Q , is a physical quantity.
A 35 L tank of oxygen is at 42°C with an internal pressure of 5000.mmHg. If the temperature changes to 88°C, what would the new pressure be ? the volume is held constant
Answer:
5730 mmHg.
Explanation:
The following data were obtained from the question:
Initial temperature (T1) = 42 °C.
Initial pressure (P1) = 5000 mmHg.
Final temperature (T2) = 88 °C.
Final pressure (P2) =.?
Next we shall convert celsius temperature,T(°C) to Kelvin temperature, T(K).
This can be obtained as follow:
T(K) = T(°C) + 273
Initial temperature (T1) = 42 °C.
Initial temperature (T1) = 42 °C + 273 = 315 K
Final temperature (T2) = 88 °C.
Final temperature (T2) = 88 °C + 273 = 361 K
Finally, we shall determine the new pressure.
Since the volume of the container is constant, the new pressure can be obtained as follow:
Initial temperature (T1) = 315 K.
Initial pressure (P1) = 5000 mmHg.
Final temperature (T2) = 361 K.
Final pressure (P2) =.?
P1/T1 = P2/T2
5000/315 = P2/361
Cross multiply
315 x P2 = 5000 x 361
Divide both side by 315
P2 = (5000 x 361) / 315
P2 = 5730.1 ≈ 5730 mmHg
Therefore, the new pressure is 5730 mmHg.
Which of the following is a halogen?
O A. Neon (Ne)
B. Iodine (1)
O C. Oxygen (0)
O D. Potassium (K)
Answer:
[tex]\boxed{\mathrm{Iodine}}[/tex]
Explanation:
Halogens are elements in group 17 or 7 in the periodic table.
Iodine is a halogen.
Therefore, iodine, an Halogen
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