Answer:
Cm = n/V
n(H2SO4) = 245/98 = 2.5 mol
Cm(H2SO4) = 2.5/1 = 2.5 M
Explanation:
According to the Vaporization Heat table, the heat needed for 1 mol of H2O to evaporate at 100°C is 40.7KJ and 44.0KJ/mol is needed to evaporate H2O at 25°C. Thus 44.0-40.7=3.7KJ is the energy needed to heat H2O to 100°C from 25°C.
However, according to the heat capacity of H2O, 3.7KJ will only warm the water by ~+43°C, which is not enough to reach 100°C starting from 25°C!
Am I missing something?!
Suppose you have a material in it's liquid phase. As you give energy to that liquid, the temperature of the liquid will increase gradually, and the relation between the increase of temperature and the given energy is the specific heat.
Now, there is a point, a critical point, where the temperature stops to increase, which means that we are near a change of phase. So from this point on, the energy is not used to increase the kinetic energy of the particles (which would increase the temperature), the energy is used to break the bonds and allow a change of phase, for example, from liquid to gas.
So, we know that if you have a mol of water at 100°C, then you need to add 40.7 kJ of energy to change the phase of the water from liquid to gas phase.
This means that if you have a mol of water and you give that exact energy, the temperature will not change, instead, you now will have a mol of water at the temperature of 100°C.
Similarly with the case at 25°C (which happens for a particular pressure only)
So the heat of vaporization can not really be related to increases in temperature as you thought.
For changes in temperature, you need to use the specific heat.
We know that for water it is:
c = 4.184 J/g*°C = 76.15 J/mol*°C
So, if you want to increase the temperature from 25° to 100°
This means an increase of 75°C of one mol of water.
We just need to multiply the above number by:
1mol*(75°C)
Energy needed = (76.15 J/mol*°C)*1mol*(75°C) = 5,711.25 J
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2- . the number of waves in n *10 bohr's orbit are
When cyclopentane undergo free-radical substitution with bromine (Br2 /Heat) the product:
a. Bromo cyclopentene
b. Bromo cyclopentane + HBr
c. Bromo cyclopentene + HBr
Explanation:
b. Bromo cyclopentane + HBr
Which one of the following compounds
contains ionic bonds?
a) NI3
B) HF
c) SiO2
d) CaO
Your answer is CaO.I hope that my answer helped you..
The condensation of chromosomes is inducted in?
Answer:
Chromosome condensation, the landmark event at the onset of prophase, often begins in isolated patches of chromatin at the nuclear periphery. Later, chromosome condense into two threads termed sister chromatids that are closely paired along their entire lengths.
Explanation:
hope dis help & may I have brainly plz
How can beta particles be dangerous to living cells?
A. They move fast and penetrate the skin.
B. They are very high in energy and can travel through most
materials.
C. They move slowly but are very large.
D. They are very low in energy but remain in the body for a long time.
how is the akin of frog similar to a fish
Answer:
Have you ever touched a fish? Most fish will feel a bit rough - due to their scales. Some, like sharks, will feel like sandpaper. Even fish with small, smoother scales will feel a bit like that. Amphibians don’t have scales, and most species will be wet to some degree - they have to keep their skin moist or they’ll die. A few groups, like toads and newts, have rougher skin, which is heavier and thicker, which allows them to retain moisture better away from water.
Functionally, the big thing about amphibian skin is that it is semi-permeable. Amphibians can breathe through their skin - all amphibians can get some oxygen through their skin, but some species of salamanders get all their oxygen that way - they have no lungs or gills. The skin can also allow water in - sort of like a paper towel. The bad thing is that other chemicals can pass through the skin, too - pollutants and other chemicals tend to affect amphibians far more than they do other groups.
Amphibians also shed their skin - fish do not. People don’t tend to see frogs shedding their skin often, though, since they eat it to regain nutrients and other resources in the skin.
Finally, since amphibian skin offers no defense against predators in the way that scales do, and limited barrier against disease the way non-amphibian skin does (shedding helps), the skin of many amphibians contain toxins, and some of them have anti-fungal properties (typically due to symbiotic bacteria). Many species have evolved chemical defenses in the skin, while others have glands that produce toxins that can be secreted outside of the skin.
The skin can withstand dessication more than the fish.
They have moist skin used as respiratory surface during deep sleep / hibernation.
They have moist skin due to secretion of mucus by glands under the skin.
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Is Water and kerosine a mixture
Answer:
No.Kerosene oil and water do not mix with each other and form two separate layers.
Answer:
No
Explanation:
They cannot be mixed together they will form upper and lower layer
When a marble is dropped into a beamer of water
Answer:
The water will rise.Explanation:
hope this helps you
-Sweety<3The mass of the marble is greater than that of the water. The marble weighs more than an equivalent volume of the water. The force from dropping the marble breaks the surface tension of the water. The marble has greater mass and volume than the water.
J00
Sugar
(C2H2011)
260
KNO
220
180
Solubility (g solute per 100 g H,0)
140
NaNO,
NaBr
100
KBr
60
КСІ
Naci
20
0
0
20
Ce (50)
40 60
Temperature (°C)
80
100
Which compound would make a saturated solution if 98 grams were
dissolved in 100 grams of solution at 80 degrees Celsius?
O KBr
O Sugar
OKCI
O NaCl
alish
Gu
Magnesium metal is reacted with hydrochloric acid to produce
hydrogen gas. A sample of hydrogen gas is collected over water
in a eudiometer at 28.0°C. The atmospheric pressure is 636
mmHg. Determine the pressure (in atm) of the hydrogen gas
produced
Pressure =
atm
The pressure of hydrogen gas is 607.7 mmHg
According of Dalton's law of Partial pressure, the total pressure of a mixture of gases is the sum of the partial pressures of the individual gases in the mixture.
We can now write;
The for hydrogen collected over water, we have a mixture of hydrogen gas and water vapour.
Total pressure = pressure of hydrogen gas + vapour pressure of water
Pressure of hydrogen gas = Total pressure - vapour pressure of water
Pressure of hydrogen gas = 636 mmHg - 28.3 mmHg
Pressure of hydrogen gas = 607.7 mmHg
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write anode and cathode in Zn-Ag galvanic cell
Explanation:
Zinc is the anode (solid zinc is oxidised). Silver is the cathode (silver ions are reduced).
By convention in standard cell notation, the anode is written on the left and the cathode is written on the right. So, in this cell: Zinc is the anode (solid zinc is oxidised). Silver is the cathode (silver ions are reduced).
Complete the following nuclear equations. I recommend filling in the atomic number below each symbol. Instead of using superscripts in our answers, put each answer in the corresponding box. A). 54Fe 4He --> 2 1n _____
Answer:
gamma ray
Explanation:
How many shapes contains the same text: KTKEIHLPEQMKJAPDEK
In this figure, four shapes contains the same text as in the red oval. The text given in the red oval is KTKEIHLPEQMKJAPDEK.
What is shape?Shape is "the form of an object or its outline, outer boundary or outer surface".
What is text?Text is "a collection of words or letters that are understandable by the reader".
What is an oval?Oval is a rounded and slightly elongated outline or shape like that of an egg.
Hence, four shapes contains the same text as in the red oval.
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What is molarity?
A. A measure of saturation.
B. A ratio of moles of solvent to moles of solution.
C. A measure of moles.
D. A measure of concentration.
Answer:
Molarity is a measure of concentration
I Hope its right if not so advance sorry :)
The molarity measures the number of moles of the solute present per liter of the solution and it measures the concentration of the solution. option D is correct.
What is molarity?Molarity is the amount or the number of moles present in per liter of the solution it is the unit to measure the concentration of the moles.
Unit of molarity will be moles per liter and the temperature does not affect the molarity of the solution. molarity can be calculated by dividing the concentration of the solution by the molar mass of the given element.
molarity = weight / mass × 1000/ volume in liters.
With the help of this formula, we can calculate the molarity.
Therefore, molarity measures the number of moles of the solute present per liter of the solution and it measures the concentration of the solution. option D is correct.
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PLEASE HELP ASAP!!!
Answer:
I don't know What can I do.
Place the following elements in order of decreasing atomic size: lead, phosphorus, oxygen, cesium, barium, and silicon.
Rank from largest to smallest. To rank items as equivalent, overlap them.
Cs, O, P, Si, Ba, Pb
Answer:
Cs> Ba> Pb>Si> P>O
Explanation:
Recall that atomic size decreases across a period and increases down the group.
As we move from Cs to Ba, the atomic size decreases across the period. Lead is larger than silicon since atomic size increases down the group.
Between phosphorus and oxygen, phosphorus is larger than oxygen as you move across the period.
oxide. b) Silicon dio
43. What is the nature of an enzyme?
a) Vitamin. b) Lipid. c) Carbohydrate. d) Protein
44. Name the enzyme which catalyzes the oxidation-reduction reaction?
a) Transaminase. b) Glutamine synthetase. c) Phosphofructokinase. d) Oxidoreductase
nontido
Answer:
43) protein
44) oxidoreductase
The Lewis dot model of a molecule is shown.
Based on the model, which of the following is true?
Each carbon has three lone pairs of electrons on it.
The octet of carbon atom remains incomplete in the molecule.
The two carbon atoms share a total of six electrons with each other.
The difference between the electronegativity of carbon and hydrogen is greater than 1.7.
Answer:
The two carbon atoms share a total of six electrons with each other.
Explanation:
Looking at the structure of the molecule H-C≡C-H as shown in the question, we will notice that there exists a triple bond between the two carbon atoms.
Each bond between the two carbon atoms represents two electrons shared. Since there are three bonds between the two carbon atoms, then a total of six electrons were shared between the two carbon atoms hence the answer chosen above.
what volume will it occupied 40 degrees celsius a gas sample was collected when a temperature is 27 degrees celsius and the volume of 1 L
Using Charles law
[tex]\boxed{\sf \dfrac{V_1}{T_1}=\dfrac{V_2}{T_2}}[/tex]
[tex]\\ \sf\longmapsto V_1T_2=V_2T_1[/tex]
[tex]\\ \sf\longmapsto 1(40)=27V_2[/tex]
[tex]\\ \sf\longmapsto V_2=\dfrac{40}{27}[/tex]
[tex]\\ \sf\longmapsto V_2=1.48\ell[/tex]
The number of organic compounds that have been reported in 2019 is more than 10 million. This is due to carbon's ability to bond to other carbon molecules, called
electron affinity.
ionic bonding.
catenation.
electronegativity.
Answer:
catenation
Explanation:
Carbon atoms have four electrons to share in bonding environments to get to the ideal octet. To do this, it bonds with other carbon molecules, called catenation. Catenation is the ability of an atom to bond and share electrons with other atoms of its kind.
A 10.53 mol sample of krypton gas is maintained in a 0.8006 L container at 299.8 K. What is the pressure in atm calculated using the
van der Waals' equation for Kr gas under these conditions? For Kr, a = 2.318 L'atm/mol and b = 3.978x10²L/mol.
Answer:
-401.06 atm
Explanation:
Applying,
P = (nRT/V-nb)-(an²/V²)............... Equation 1
Where P = Pressure, R = Universal gas constant, V = molar Volume, T = Temperature in Kelvin, a = gas constant a , b = gas constant b, n = numbers of mole
From the question,
Given: T = 299.8 K, V = 0.8006 L, a = 2.318 L.atm/mol, b = 3.978×10²L/mol
Constant: R = 0.0082 atm.dm³/K.mol
Substitute these values into equation 1
P = [(0.0082×299.8×10.53)/(0.8006-(10.53×397.8)]-[(10.53²×2.318/0.8006²)]
P = (25.89/-4188.0334)-(400.995)
P = -0.0618-400.995
P = -401.06 atm
Calculate the volume of a 89.51 g sample of carbon dioxide at 281.8 K and 843.9 torr. Round your answer
to the nearest L. Do not include units.
Answer:
1,000.000
Explanation:
What happens as energy from sun warms the earth unevenly?
Answer:
Solar heating of the Earth's surface is uneven because land heats faster than water, and this causes air to warm, expand and rise over land while it cools and sinks over the cooler water surfaces.This differential heating is passed on to the air above by conduction which causes air expansion and changes in pressure.
Copper crystallizes in a face-centered cubic unit cell. The density of copper is 8.94 g/cm3. Calculate the length of the edge of the unit cell in pm.
a) 461 pm
b) 361 pm
c) 261 pm
d) 161 pm
e) None of the above
Answer:
361.4 pm is the length of the edge of the unit cell
Explanation:
First, let's calculate the average volume each atom is taking. Start with calculating how many moles of copper we have in a cubic centimeter by looking up the atomic weight. Atomic weight copper = 63.546 Now divide the mass by the atomic weight, getting 8.94 g / 63.546 g/mol = 0.140685488 mol And multiply by Avogadro's number to get the number of atoms: 0.140685488 * 6.022140857x10^23 = 8.472278233x10^22 Now examine the face-centered cubic unit cell to see how many atoms worth of space it consumes. There is 1 atom at each of the 8 corners and each of those atoms is shared between 8 unit cells for for a space consumption of 8/8 = 1 atom. And there are 6 faces, each with an atom in the center, each of which is shared between 2 unit cells for a space consumption of 6/2 = 3 atoms. So each unit cell consumes as much space as 4 atoms. Let's divide the number of atoms in that cubic centimeter by 4 to determine the number of unit cells in that volume. 8.472278233x10^22 / 4 = 2.118069558x10^22 Now calculate the volume each unit cell occupies. 1 cm^3 / 2.118069558x10^22 = 4.721280262x10^-23 cm^3 Let's get the cube root to get the length of an edge. (4.721280262x10^-23 cm^3)^(1/3) = 3.61426x10^-08 cm Now let's convert from cm to pm. 3.61426x10^-08 cm / 100 cm/m * 1x10^12 pm/m = 361.4 pm Doing an independent search for the Crystallographic Features of Copper, I see that the Lattice Parameter for copper at at 293 K is 3.6147 x 10^-10 m which is in very close agreement with the calculated amount above. And since metals expand and contract with heat and cold, I assume the slight difference in values is due to the density figure given being determined at a temperature lower than 293 K.
When (R)-2-chloro-3-methylbutane is treated with potassium tert-butoxide, a monosubstituted alkene is obtained. When this alkene is treated with HBr, a mixture of products is obtained. Identify all of the expected products.
Answer:
See explanation and image attached
Explanation:
The reaction of (R)-2-chloro-3-methylbutane with potassium tert-butoxide yields a monosubstituted alkene .
Since the base is bulky, the Hoffman product predominates because attack occurs at the less hindered carbon atom to yield the major product as shown.
The alkene reacts with HBr at the secondary carbon atom to yield a carbocation intermediate which is flat and planar. Attack on either face of the carbocation yields a racemic mixture of the (2R) and (2S) products.
Rearrangement of the carbocation to yield a tertiary carbocation gives the 2-bromo-2-methyl butane product as shown in the image attached.
Three important nutritional additions to training for a long distance race are
O Protein
O Water
O Increase calories
O All of the answer choices
A chemist is preparing to carry out a reaction that requires 5.75 moles of hydrogen gas. The chemist pumps the hydrogen into a 10.5 L rigid steel container at 20.0 °C. To what pressure, in kPa, must the hydrogen be compressed? (Show all work for full credit and circle your final answer) *
Answer:
The hydrogen must be compressed to 1333.13302 kPa.
Explanation:
An ideal gas is characterized by three state variables: absolute pressure (P), volume (V), and absolute temperature (T). The relationship between them constitutes the ideal gas law, an equation that relates the three variables if the amount of substance, number of moles n, remains constant and where R is the molar constant of the gases:
P * V = n * R * T
In this case:
P= ?V= 10.5 Ln= 5.75 molesR= 0.082 [tex]\frac{atm*L}{mol*K}[/tex]T= 20 C= 293 K (being 0 C= 273 K)Replacing:
P* 10.5 L= 5.75 moles* 0.082 [tex]\frac{atm*L}{mol*K}[/tex] * 293 K
Solving:
[tex]P=\frac{5.75 moles* 0.082 \frac{atm*L}{mol*K} * 293 K}{10.5 L}[/tex]
P= 13.157 atm
If 1 atm is equal to 101.325 kPa, then 13.157 atm is equal to 1333.13302 kPa.
The hydrogen must be compressed to 1333.13302 kPa.
In the reaction HCI + NH4OH --> NH4CI+H2O, which compound has an element ratio of 1:4:1?
H2O
NH4Cl
HCI
ΝΗ4ΟΗ
The compound in this reaction which is having the elemental ratio of 1:4:1 is NH₄Cl where nitrogen and chlorine are of one mole each with 4 hydrogens.
What is elemental ratio?Elemental ratio of a compound is the ratio of number of atoms of each elements in that compound. The elemental ratio can be determined from the molecular formula of compounds.
The given reaction is a double displacement reaction. Here, the Cl group is replaced to the ammonia and OH group is replaced to the water. Thus, two species is replaced in the reaction.
In NH₄Cl, there are one nitrogen, 4 hydrogens and one chlorine atom. Therefore, the elemental ratio of the compound is 1:4:1. The elemental ratio of water is 2:1 and HCl is 1:1 and that in NH₄OH is 1:5:1. Hence, option b is correct.
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.formular for Charles' law
Explanation:
Hey there!
Charles law states that the volume of gas is directly proportional to the absolute temperature at constant pressure.
As the fact is, at a constant pressure the volume of fix amount of dry gas is directly proportional to absolute temperature from Charles law.
Since V and T are directly varying directly, we can write the equation using constant "k".
V/T = k
In this case the value of k depends on the pressure of gas, the amount of gas and also unit volume.
V/T = k .........(i)
Let us consider V1 and T1 the Volume and temperature of the ideal gases.
Then the equation is;
V1/T1 =k........(ii)
After this let change the temperature and volume be T2 and V2, respectively.
Then the equation is:
V2/T2 = k.......(iii)
Now; Equating equation (ii) and (iii)…
V1/T1 = V2/T2
So, this the formula. (i.e V1/T1 = V2/T2).
Hope it helps!
