Answer:
40
Explanation:
because the atomic number is how many electrons
Determine the molarity and mole fraction of a 1.09 m solution of acetone (CH3COCH3) dissolved in ethanol (C2H5OH). (Density of acetone
Answer:
Molarity = 0.809 M
mole fraction = 0.047
Explanation:
The complete question is
Calculate the molarity and mole fraction of acetone in a 1.09-molal solution of acetone (CH3COCH3) in ethanol (C2H5OH). (Density of acetone = 0.788 g/cm3; density of ethanol = 0.789 g/cm3.) Assume that the volumes of acetone and ethanol add.
Solution -
Solution for molarity:
1.09-molal means 1.09 moles of acetone in 1.00 kilogram of ethanol.
1)
Mass of 1.09 mole of acetone
= 1.09 mol x 58.0794 g/mol = 63.306 g
Density of acetone = 0.788 g/cm3
Thus, volume of 1.09 moles of acetone = 63.306 g/0.788 g/cm3 = 80.34 cm3
For ethanol
1000 g divided by 0.789 g/cm3 = 1267.427 cm3
Total volume of the solution = Volume of acetone + Volume of ethanol = 80.34 cm3 + 1267.427 cm3 = 1347.765 cm3 = 1.347 L
a) Molarity:
1.09 mol / 1.347 L = 0.809 M
Mole Fraction
a) moles of ethanol:
1000 g / 46.0684 g/mol = 21.71 mol
b) moles of acetone:
1.09 / (1.09 + 21.71) = 0.047
If the Bunsen burner gave a luminous flame and some soot was deposited on
the tube, what effect would this situation have on the calculated % of oxygen ?
Explanation:
If bunsen burner gave a luminous flame then there will deposition of soot at the bottom of the test tube which is actually pure carbon.
This deposition of soot actually depicts that there is incomplete combustion reaction that has taken place.
Also, the deposition of soot will provide a limited supply of oxygen to the reaction that has been calculated.
Therefore, in order to avoid any formation of soot it is advisable to adjust the burner flame till it produces a blue flame.
Which organ produces the female hormone estrogen
Answer:
Ovary
Explanation:
ovaries produce the most estrogen in females.
A single ___ bond is made when two atoms share a pair of ____
Answer:
covalent
valence electrons
Explanation:
The attraction between two atoms that share a pair of valence electrons is known as a covalent bond. The nuclei of both atoms are drawn to the shared electrons. This results in a molecule with two or more atoms. Covalent bonds are formed solely between nonmetal atoms.
Between atoms of the same element or between atoms of different elements, covalent bonds can form. A new substance termed a covalent compound is formed when atoms of various elements create covalent bonds.
The solubility of an ionic compound can be expressed as the number of moles of the compound that will dissolve per liter of solution (molarity). The saturated solution has approximately____(a) sodium ions dissolved in it (give an estimate of the average value.) The solution (not the solid) contains approximately_____(b) moles of sodium ions.
Answer:
Number of moles of sodium dissolved = 6.0 *10^23
Explanation:
The image for the question is attached
Solution
a) Total 181 ions of Na are dissolved
b)
The number of moles of sodium dissolved = 181/6.023 *10^23
Number of moles of sodium dissolved = 5.987 * 10^23
Number of moles of sodium dissolved = 6.0 *10^23
BRAINISEST & 10 POINTS
Answer:
In order from left to right, 7 (gamma), 5 (ultraviolet, now continue pattern), 4, 6, 2, 3, 1.
When water and alcohol are mixed, the final volume is less than the total of volume of alcohol plus water added due to .......
Answer:
molecules take up more space
In the following reaction, C5H12(1) + 8 O2 (g) - 6 H2O (g) + 5 CO2 (g), how many
moles of water (H20) are produced by 14.2 moles of O2?
Answer:
10.65 moles
Explanation:
O2:H2O
8:6
14.2:x
x= 10.65 moles
How many grams are in 0.375 mol LiBr? (MM LiBr=86.85 g/mol)
O 32.6 g
O 0.00315 g
O 0043 g
O 86.8 g
Answer:
32.57g
Explanation:
mass = mole x molar mass
mass of LiBr = 0.375 x 86.85
mass = 32.57g
The stream table shows the time needed for water to soak into the playfield soil.
Answer:
TRUE
Explanation:
plz brian list
Answer:
True
Explanation:
Limitations of Pearson rule
scenario Juan and Maria Lopez wish to invest in a no-risk savings account. They currently have 530,000 in an account bearing 5.25 % annual interest, compounded continuously. The following options are available to them.
Answer:
The amount after three year is 617934.1302
Explanation:
Complete question
A person places $530,000 in an investment account earning an annual rate of 5.25%, compounded continuously. Using the formula V = Pe^{rt}V=Pe rt , where V is the value of the account in t years, P is the principal initially invested, e is the base of a natural logarithm, and r is the rate of interest, determine the amount of money, to the nearest cent, in the account after 3 years
Solution
The formula for calculating compound interest is
[tex]A = p (1 + \frac{r}{n})^{nt}[/tex]
Substituting the given values we get -
[tex]A = 530,000 (1 + \frac{5.25}{100})^3\\A = 530,000 * ( 1+ 0.0525)^3\\A = 530,000 * ( 1.0525)^3\\A = 617934.1302[/tex]
The amount after three year is 617934.1302
how many moles of Carbon are in 3.06 g of Carbon
Answer:
[tex]\boxed {\boxed {\sf 0.255 \ mol \ C }}[/tex]
Explanation:
If we want to convert from grams to moles, the molar mass is used. This is the mass of 1 mole. They are found on the Periodic Table as the atomic masses, but the units are grams per mole (g/mol) instead of atomic mass units (amu).
Look up the molar mass of carbon.
Carbon (C): 12.011 g/molSet up a ratio using the molar mass.
[tex]\frac {12.011 \ g \ C}{ 1 \ mol \ C}[/tex]
Since we are converting 3.06 grams to moles, we multiply by that value.
[tex]3.06 \ g \ C*\frac {12.011 \ g \ C}{ 1 \ mol \ C}[/tex]
Flip the ratio. This way, the ratio is still equivalent, but the units of grams of carbon cancel.
[tex]3.06 \ g \ C* \frac{1 \ mol \ C}{12.011 \ g\ C}[/tex]
[tex]3.06 * \frac{1 \ mol \ C}{12.011 }[/tex]
[tex]\frac {3.06}{12.011 } \ mol \ C[/tex]
[tex]0.25476646 \ mol \ C[/tex]
The original measurement of grams (3.06) has 3 significant figures, so our answer must have the same. For the number we calculated, that is the thousandth place.
0.25476646The 7 in the ten-thousandth place tells us to round the 4 up to a 5.
[tex]0.255 \ mol \ C[/tex]
3.06 grams of carbon is approximately 0.255 moles of carbon.
Consider four different samples: aqueous LiBr, molten LiBr, aqueous LiF, and molten LiF. Current run through each sample produces one of the following products at the anode: liquid bromine, fluorine gas, or oxygen gas. Match each sample to its anodic product from aqueous LiBr, Molten LiBr, aqueous LiF, and molten LiFA. Liquid bromine,
B. Fluorine gas,
C. oxygen gas
Answer:
Following are the solution to the given question:
Explanation:
Please find the matching in attached file.
During the electrolysis of Molten LiBr : Li is reduced and Br are oxidized .
Lithium Metal is produced at the Cathod during the electrolysis of Molten LiBR .
In the aquous LiBr : In aquous LiBr potential of Li is greater than the of water then Li is reduced to produce solid Li ion. As well As aqueous LiF ( electrolysis)and Molten LiF electrolysis produce the gas.
aqueous LiF: Oxygen gas.
Molten LiF : Flourine gas.
The mass of 1.63×10^21 silicon atoms
Answer:
I think it is 7.60 X 1
but if it's not srry
Calculate the number of hydrogen atoms present in 40g of urea, (NH2)2CO
Answer: There are [tex]16.14 \times 10^{23}[/tex] atoms of hydrogen are present in 40g of urea, [tex](NH_{2})_{2}CO[/tex].
Explanation:
Given: Mass of urea = 40 g
Number of moles is the mass of substance divided by its molar mass.
First, moles of urea (molar mass = 60 g/mol) are calculated as follows.
[tex]Moles = \frac{mass}{molar mass}\\= \frac{40 g}{60 g/mol}\\= 0.67 mol[/tex]
According to the mole concept, 1 mole of every substance contains [tex]6.022 \times 10^{23}[/tex] atoms.
So, the number of atoms present in 0.67 moles are as follows.
[tex]0.67 mol \times 6.022 \times 10^{23} atoms/mol\\= 4.035 \times 10^{23} atoms[/tex]
In a molecule of urea there are 4 hydrogen atoms. Hence, number of hydrogen atoms present in 40 g of urea is as follows.
[tex]4 \times 4.035 \times 10^{23} atoms\\= 16.14 \times 10^{23} atoms[/tex]
Thus, we can conclude that there are [tex]16.14 \times 10^{23}[/tex] atoms of hydrogen are present in 40g of urea, [tex](NH_{2})_{2}CO[/tex].
A sample of aluminum absorbed 9.86 J of heat and its temperature increased from 23.2 and 30.5 degrees * C . What is the mass of the aluminum? Th specific heat of aluminum is 0.902 J/g^ C . Round your answer to 2 significant figures. Do not include units in your answer. *
Explanation:
H=mc×∆©
9.86=m×0.902×(30.5-23.2)
m=1.5
Explanation:
The specific heat of a substance is the amount of heat required to raise the temperature of 1 gram of the substance by 1 degree Celsius. The formula for calculating the heat absorbed or released by a substance is `q = mcΔT`, where `q` is the heat absorbed or released, `m` is the mass of the substance, `c` is the specific heat of the substance, and `ΔT` is the change in temperature.
In this case, we can use this formula to solve for the mass of the aluminum sample. We know that `q = 9.86 J`, `c = 0.902 J/g°C`, and `ΔT = 30.5°C - 23.2°C = 7.3°C`. Plugging these values into the formula, we get:
`9.86 J = m * 0.902 J/g°C * 7.3°C`
Solving for `m`, we find that the mass of the aluminum sample is approximately `1.5 g`, rounded to 2 significant figures.
PLEASE mark as Brainliest
does anyone know this??
Answer: C2H6O
Explanation: It is C2H6O with a molar mass of 46.07 g/mol.
A chemist must dilute of aqueous silver perchlorate solution until the concentration falls to . He'll do this by adding distilled water to the solution until it reaches a certain final volume. Calculate this final volume, in liters. Round your answer to significant digits
The given question is incomplete, the complete question is:
A chemist must dilute 54.1 mL of 20.2 M aqueous silver perchlorate (AgC102) solution until the concentration falls to 3.00 M. He'll do this by adding distilled water to the solution until it reaches a certain final volume. Calculate this final volume, in liters. Round your answer to 3 significant digits.
Answer:
The correct answer is 0.364 L.
Explanation:
A solution is made less concentrated by diluting it with a solvent. There is no change in the number of moles when more solvent is added to the solution. In case, if the solution is diluted from V1 to V2, a change is noticed in the molarity of the solution based on the given equation,
M1V1 = M2V2
In the given case, the V1 or the volume of the original solution is 54.1 ml, M1 or the molarity of the original solution is 20.2 M.
The M2 or the molarity of the diluted solution is 3.00 M, there is a need to find the V2 or the volume of the diluted solution.
Now by putting the values in the equation we get,
= 20.2M * 54.1 ml = 3.0 M * V2
V2 = 364.27 ml
It is known that 1000 ml is equivalent to 1L, therefore, 1 ml = 0.001 L
Now, the value of V2 will be,
= 364.27 * 0.001 L = 0.36427 L or 0.364 L
When fuels are burned, the chemical energy that is released can be used to generate another form of energy, such as heat, light,motion,or electricity. This is called
Answer: When fuels are burned, the chemical energy that is released can be used to generate another form of energy, such as heat, light, motion, or electricity. This is called combustion.
Explanation:
The chemical energy present in fuels actually releases when these fuels are burned or by combustion.
Hence when fuels are burned, the chemical energy that is released can be used to generate another form of energy, such as heat, light, motion, or electricity. This is called combustion.
For example, gasoline present in vehicles burns and undergoes chemical change which is then converted into thermal energy. This thermal energy then converts into mechanical energy due to which car moves.
Thus, we can conclude that when fuels are burned, the chemical energy that is released can be used to generate another form of energy, such as heat, light, motion, or electricity. This is called combustion.
please answer all three of these questions
Answer:
I think it's 1.D
2.C
3.C
my apologies if it's incorrect
The table below shows some characteristics of three different types of muscles
Answer: Type A are cardiac muscles Type B are skeletal muscles, and Type C are smooth muscles.
Explanation: sub to technoblade :P
PLEASE HELP ME!!!!!!!
Answer:
The heat capacity of the metal underneath the gold is 0.431 J/g°C
Explanation:
Using the formula as outlined in the image:
Q = m × c × ∆T
Where;
Q = amount of heat energy (J)
m = mass of substance (g)
c = specific heat capacity (J/g°C)
∆T = change in temperature (°C)
According to the information in this question;
Q = 503.9J
m = 23.02g
c = ?
∆T = 74°C - 23.2°C = 50.8°C
Using Q = m × c × ∆T
c = Q ÷ m∆T
c = 503.9 ÷ (23.02 × 50.8)
c = 503.9 ÷ 1169.42
c = 0.431 J/g°C
From the above heat capacity of the metal underneath the gold, it is obvious that the metal is not pure gold (c = 0.129J/g°C)
HELP PLZ
Calculate the percent composition by mass of iron in Fe(NO3)3
PbO2 + 4HCl --- PbCl2 + Cl2 + 2H2O who buys electrons and who loses electrons?
Answer: Electrons are taken up by [tex]PbO_2[/tex] and they are lost by [tex]HCl[/tex]
Explanation:
Redox reaction is defined as the reaction in which oxidation and reduction take place simultaneously. It is also called the reaction where the exchange of electrons takes place.
An oxidation reaction is defined as the reaction in which a chemical species loses electrons takes place. In this reaction, the oxidation state of a substance gets increased.
A reduction reaction is defined as the reaction in which a chemical species gains electrons takes place. In this reaction, the oxidation state of a substance gets reduced.
For the given chemical reaction:
[tex]PbO_2+4HCl\rightarrow PbCl_2+Cl_2+2H_2O[/tex]
The half-reactions for this redox rection follows:
Oxidation half-reaction: [tex]2HCl\rightarrow ClO_2 + 2e^-[/tex]
Reduction half-reaction: [tex]PbO_2+2e^-\rightarrow PbCl_2[/tex]
Hence, electrons are taken up by [tex]PbO_2[/tex] and they are lost by [tex]HCl[/tex]
What is the answers?
Is my answer right?
Answer:
I say the correct answers are primary and secondary and teriary.
Explanation:
I say you are right!!
Which waves are blocked by the atmosphere? A. gamma rays B. visible light C. radio waves D. infrared waves
Answer: look at the explanation and try to work it
Explanation: in contrast, our atmosphere blocks most ultraviolet light (UV) and all X-rays and gamma-rays from reaching the surface of Earth. Because of this, astronomers can only study these kinds of light using detectors mounted on weather balloons, in rockets, or in Earth-orbiting satellites.
Please type out all of your calculations for this dilution equation: In your vitamin C experiment, it calls for a 5% concentration of iodine. However, your 7 fluid oz. tincture of iodine contains 70% iodine. How would you dilute this
Answer:
The original7 fluid oz. 70% tincture of iodine is diluted to 98 fluid oz. to obtain a 5% solution.
Explanation:
Dilution is a technique employed in experimental sciences such as chemistry and biochemistry as well as in medicine to obtain a less concentrated solution from a more concentrated one.
The dilution formula is the most important formula required in dilution. The dilution formula is given as: C1V1 = C2V2
Where C1 is the initial concentration of the stock solution;
V1 is the volume of the stock solution required;
C2 is the final concentration of the diluted solution to be prepared;
V2 is the final volume of the diluted solution.
Using the dilution formula to determine the answer to the above question:
C1 = 70% = 0.7; V1 = 7 fluid oz.; C2 = 5% = 0.05; V2 = ?
To determine V2, it is made subject of the dilution formula:
V2 = C1V1/C2
V2 = (0.7 × 7) / 0.05
V2 = 98 fluid oz.
Therefore, the original7 fluid oz. 70% tincture of iodine is diluted to 98 fluid oz. to obtain a 5% solution.
HELP ME OMG
A sample of xenon gas collected at a pressure of 1.15 atm and a temperature of 279 K is found to
occupy a volume of 786 milliliters. How many moles of Xe gas are in the sample?
mol
n = 0.0395 mol Xe
Explanation:
Use the ideal gas law:
PV = nRT
n = PV/RT
= (1.15 atm)(0.786 L)/(0.08205 L-atm/mol-K)(279K)
= 0.0395 mol Xe
Brainiest and 10 points
Which has a HIGHER frequency?
A. Orange light
B. Blue light
Answer:
A. Orange light
Explanation:
According to the band spectrum of white light ( ROYGBIV )
Answer:
I think it blue light is higher