Answer:
0.18mol
Explanation:
Given parameters:
Mass of CaCl₂ = 20g
Unknown:
Number of moles = ?
Solution:
To solve this problem;
Number of moles = [tex]\frac{mass}{molar mass}[/tex]
Molar mass of CaCl₂ = 40 + 2(35.5) = 111g/mol
Number of moles = [tex]\frac{20}{111}[/tex] = 0.18mol
What are the 3 known forms of hydrogen called
Answer:hydrogen, deuterium, and tritium.
Explanation:
How many moles of CO2 must dissolve in excess water to produce 12 moles of
H2CO3?
Answer:
12 moles of CO₂.
Explanation:
We'll begin by writing the balanced equation for the reaction. This is illustrated below:
CO₂ + H₂O —> H₂CO₃
From the balanced equation above,
1 mole of CO₂ dissolves in water to produce 1 mole of H₂CO₃.
Finally, we shall determine the number of moles of CO₂ that will dissolve in water to produce 12 moles of H₂CO₃. This can be obtained as follow:
From the balanced equation above,
1 mole of CO₂ dissolves in water to produce 1 mole of H₂CO₃.
Therefore, 12 moles of CO₂ will also dissolve in water to produce 12 moles of H₂CO₃.
Thus, 12 moles of CO₂ is required.
In a first-order decomposition reaction. 58.6% of a compound decomposes in 11.7 min. How long (in min) does it take for 80.2% of the compound to decompose
Answer:
t = 21.5 min.
Explanation:
Hello!
In this case, since the kinetics of a first-order reaction is:
[tex]\frac{[A]}{[A]_0}=exp(-kt)[/tex]
Thus, since we are given the 11.7 min for a 58.6-% consumption, we can compute the rate constant, k:
[tex]ln(1-0.586)=-kt\\\\k=\frac{ln(0.414)}{-t}=\frac{-0.882}{11.7min}=0.0754min^{-1}[/tex]
Now, for the second problem, as the new consumption is 80.2%, we can compute the required time as shown below:
[tex]ln(1-0.802)=-kt\\\\t=\frac{ln(198)}{k} \\\\t=\frac{-1.62}{0.0754min^{-1}}\\\\t=21.5min[/tex]
Best regards!
Question 3 (1 point)
Consider the following unbalanced chemical equation representing the combustion of methane, yielding carbon dioxide and water.
CH4 + O2 --> CO2 + H20
If you had burned 800 g of methane, how many moles of Carbon dioxide would be produced?
a
b
Ос
122.22
8
2200
100
670
f
750
50
Answer:
50 mol
Explanation:
Mass of methane = 800 g
Number of moles of CO₂ produced = ?
Solution:
Chemical equation:
CH₄ + 2O₂ → CO₂ + 2H₂O
Number of moles of methane:
Number of moles = mass/molar mass
Number of moles = 800 g/ 16 g/mol
Number of moles = 50 mol
Now we will compare the moles of methane and carbon dioxide from balanced chemical equation.
CH₄ : CO₂
1 : 1
50 : 50
The yttrium- nuclide radioactively decays by electron capture. Write a balanced nuclear chemical equation that describes this process.
Answer:
See explanation and image attached
Explanation:
Yttrium has many isotopes, the lowest mass number of Yttrium is 89Y.
Recall that electron capture converts an electron into a proton and then into a neutron with a consequent emission of a neutrino (v).
In electron capture, the mass number of the daughter nucleus remains the same as that of the parent nucleus while the atomic number of the daughter nucleus is less than that of the parent by one unit.
An unknown element is a mixture of isotopes ¹²⁰X and ¹²²X. The average atomic mass of X is 120.59 amu. What is the percent abundance of ¹²²X?
Answer:
[tex]\%_{X-122}=29.5\%[/tex]
Explanation:
Hello!
In this case, since isotopes are atoms of the same element with equal number of protons and electrons but different atomic mass, we can write the equation used to compute the average atomic mass of the considered X:
[tex]m_X^{avr}=\%_{X-120}*120+\%_{X-122}*122[/tex]
However since both percentages compose the 100%, we can write one of those in terms of the other:
[tex]m_X^{avr} = (100\%-\%_{X-122})*120+\%_{X-122}*122[/tex]
Thus, we can solve for the percent abundance of X-122 as shown below:
[tex]120.59 = 120-\%_{X-122}*120+\%_{X-122}*122\\\\120.59-120=\%_{X-122}(122-1200)\\\\120.59-120=\%_{X-122}*2\\\\\%_{X-122}=\frac{0.59}{2}=29.5\%\\[/tex]
Thus the percent abundance of the other isotope would be 70.5 %.
Best regards!
How does the energy of the atoms in a hot cup of coffee compare to the energy of the atoms in a piece of ice?
The atoms in the cup of coffee have more energy.
The atoms in the cup of coffee have less energy.
The atoms in the cup of coffee have the same amount of energy.
Answer:
The atoms in the cup of coffee have more energy.
Explanation:
The difference between the hot cup of coffee and the piece of ice is their temperature. The hot cup of coffee has a higher temperature than the ice.
The relationship between the energy and temperature is a direct relationship. This means that higher temperature means higher kinetic energy and vice versa.
Since the hot cup of coffee has a higher temperature, it means it also have the highest amount of energy. The correct option is;
The atoms in the cup of coffee have more energy.
What is the maximum amount in moles of P2O5P2O5 that can theoretically be made from 112 gg of O2O2 and excess phosphorus
Answer:
[tex]n_{P_2O_5}^{max}=1.4molP_2O_5[/tex]
Explanation:
Hello!
In this case, since the reaction between phosphorous and oxygen to form diphosphorous pentoxide is:
[tex]2P+\frac{5}{2}O_2\rightarrow P_2O_5[/tex]
Thus, since phosphorous is in excess and oxygen and diphosphorous pentoxide are in a 5/2:1 mole ratio, we can compute the maximum moles of product as shown below:
[tex]n_{P_2O_5}^{max}=112 gO_2*\frac{1molO_2}{32.00gO_2}*\frac{1molP_2O_5}{5/2molO_2}\\\\ n_{P_2O_5}^{max}=1.4molP_2O_5[/tex]
Best regards!
3. How much force does a 15 kg baby have that is crawling through the house at an acceleration of 12 m/s2? *
Answer:
15×12=180
Explanation:
Force=Mass ×Acceleration
A 8.00 L tank at 26.9 C is filled with 5.53 g of dinitrogen difluoride gas and 17.3 g of sulfur hexafluoride gas. You can assume both gases behave as ideal gases under these conditions. Calculate the mole fraction of each gas. Round each of your answers to significant digits.
Answer:
[tex]x_{N_2F_2}= 0.415\\\\x_{SF_6}=0.585[/tex]
Explanation:
Hello!
In this case, since the mole fraction of both gases in the tank is computed via:
[tex]x_{N_2F_2}=\frac{n_{N_2F_2}}{n_{N_2F_2}+n_{SF_6}} \\\\x_{SF_6}=\frac{n_{SF_6}}{n_{N_2F_2}+n_{SF_6}}[/tex]
It means we need to compute the moles of each gas, just as it is shown down below:
[tex]n_{N_2F_2}}=5.53gN_2F_2*\frac{1molN_2F_2}{66.01gN_2F_2} =0.0838molN_2F_2\\\\n_{SF_6}=17.3gSF_6*\frac{1molSF_6}{146.06gSF_6} =0.118molSF_6[/tex]
Thus, the mole fractions turn out:
[tex]x_{N_2F_2}=\frac{0.0838mol}{0.0838mol+0.118mol}= 0.415\\\\x_{SF_6}=\frac{0.0838mol}{0.0838mol+0.0838mol}=0.585[/tex]
Best regards!
A 2.912 g sample of a compounds containing only C, H, and O was completely oxidized in a reaction that yielded 3.123 g of water and 7.691 g of carbon dioxide. Determine the empirical formula and molecular formula of the compound if it has a molar mass of 100.1 g/mol.
Answer:
Explanation:
18 gram of water contains 2 g of hydrogen
3.123 gram of water will contain 2 x 3.123 / 18 = .347 g of hydrogen .
44 gram of carbon dioxide contains 12 g of carbon
7.691 gram of carbon dioxide will contain 12 x 7.691 / 44 = 2.1 g of carbon .
So the sample will contain 2.912 - ( .347 + 2.1 ) g of oxygen .
= .465 g of oxygen .
moles of Carbon = 2.1 / 12 = .175
moles of hydrogen = .347 / 1 = .347
moles of oxygen = .465 / 16 = .029
Ratio of moles of carbon , oxygen and hydrogen ( C,O,H )
= 0.175 : 0.029 : 0.347
= .175/ .029 : 1 : .347 / .029
= 6 : 1 : 12
So empirical formula = C₆H₁₂O
Let the molecular formula be [tex](C_6H_{12}O)_n[/tex]
molecular weight = n ( 6 x 12 + 12x 1 + 16)
= 100 n
Given 100 n = 100.1
n = 1
Molecular formula = C₆H₁₂O.
The activation energy for a reaction is changed from 184 kJ/mol to 59.0 kJ/mol at 600. K by the introduction of a catalyst. If the uncatalyzed reaction takes about 6900 years to occur, about how long will the catalyzed reaction take
Answer:
The catalyzed reaction will take 2.85 seconds to occur.
Explanation:
The activation energy of a reaction is given by:
[tex] k = Ae^{-\frac{E_{a}}{RT}} [/tex]
For the reaction without catalyst we have:
[tex] k_{1} = Ae^{-\frac{E_{a_{1}}}{RT}} [/tex] (1)
And for the reaction with the catalyst:
[tex] k_{2} = Ae^{-\frac{E_{a_{2}}}{RT}} [/tex] (2)
Assuming that frequency factor (A) and the temperature (T) are constant, by dividing equation (1) with equation (2) we have:
[tex] \frac{k_{1}}{k_{2}} = \frac{Ae^{-\frac{E_{a_{1}}}{RT}}}{Ae^{-\frac{E_{a_{2}}}{RT}}} [/tex]
[tex] \frac{k_{1}}{k_{2}} = e^{\frac{E_{a_{2}} - E_{a_{1}}}{RT} [/tex]
[tex] \frac{k_{1}}{k_{2}} = e^{\frac{59.0 \cdot 10^{3}J/mol - 184 \cdot 10^{3} J/mol}{8.314 J/Kmol*600 K} = 1.31 \cdot 10^{-11} [/tex]
Since the reaction rate is related to the time as follow:
[tex] k = \frac{\Delta [R]}{t} [/tex]
And assuming that the initial concentrations ([R]) are the same, we have:
[tex] \frac{k_{1}}{k_{2}} = \frac{\Delta [R]/t_{1}}{\Delta [R]/t_{2}} [/tex]
[tex]\frac{k_{1}}{k_{2}} = \frac{t_{2}}{t_{1}}[/tex]
[tex] t_{2} = t_{1}\frac{k_{1}}{k_{2}} = 6900 y*1.31 \cdot 10^{-11} = 9.04 \cdot 10^{-8} y*\frac{365 d}{1 y}*\frac{24 h}{1 d}*\frac{3600 s}{1 h} = 2.85 s [/tex]
Therefore, the catalyzed reaction will take 2.85 seconds to occur.
I hope it helps you!
Write the quantum numbers of the last electron of Neptunium.
Answer:
Explanation:
quantum number of neptunium is
6
[tex]L_{11/2}[/tex]
A metal cube has an edge that is 11.4 mm long and a mass of 6.67 g. Calculate the density of the metal and determine the likely identity of the metal.
Answer:
d = 4.5 g/cm³
Metal cube is made up off titanium.
Explanation:
Given data:
Edge length of cube = a = 11.4 mm
Mass of metal cube = 6.67 g
Density and identity of metal = ?
Solution:
First of all we will calculate the volume of cube.
V = a³
V = (11.4mm)³
V = 1481.54 mm³
mm³ to cm³:
1481.54 mm³× 1 cm³/ 1000 mm³
1.482 cm³
Density:
d = m/v
d = 6.67 g/ 1.482 cm³
d = 4.5 g/cm³
Metal cube is made up off titanium because density of titanium is 4.5 g/cm³.
How many molecules of iodine are produced when 9.3×1026 molecules of chlorine gas react with lithium iodide?
__Cl2 + __LiI à __LiCl + __ I2
Answer:
[tex]9.3x10^{26}molec\ I_2[/tex]
Explanation:
Hello!
In this case, considering the balanced chemical reaction:
Cl₂ + 2LiI ⇒ 2LiCl + I₂
We can see there is a 1:1 mole ratio between the produced iodine and the used chlorine, thus, we infer that the number of molecules of iodine given those of chlorine turn out:
[tex]9.3x10^{26}molec\ Cl_2*\frac{6.022x10^{23}molec\ I_2}{6.022x10^{23}molec\ Cl_2} =9.3x10^{26}molec\ I_2[/tex]
Best regards!
Answer:
9.3 × 10²⁶ molecules of I₂
Explanation:
Step 1: Given data
Molecules of I₂: ?Molecules of Cl₂: 9.3 × 10²⁶ moleculesStep 2: Write the balanced single displacement reaction
Cl₂ + 2 LiI ⇒ 2 LiCl + I₂
Step 3: Calculate the molecules of I₂ produced from 9.3 × 10²⁶ molecules of Cl₂
According to the balanced equation, the molecular ratio of Cl₂ to I₂ is 1:1.
9.3 × 10²⁶ molecule Cl₂ × 1 molecule I₂/1 molecule Cl₂ = 9.3 × 10²⁶ molecule I₂
Explain why radiocarbon dating is not 100% accurate. What are the sources of some of this inaccuracy?
Answer:
Radiocarbon dating is a method used for knowing the exact age of a fossil.
Explanation:
Radiocarbon dating is a fundamental tool for archaeologists use to determine the age of objects. According to new research, it's shown that radiocarbon dating standards cannot always accurate. The reason for it lies in the climatic condition of that particular area. Variations in the radiocarbon affected cite in the Levant region like Israel, Egypt, and Jordan.
How does E. Mulsion, celebrity food scientist, define a physical reaction and what examples does he give?
Incomplete question. However, I assumed you are referring to the comments made in the online animated video (Chemical and Physical changes) by celebrity food scientist E. Mulson.
Explanation:
Recall in the video animation that E. Mulson defines physical reaction as occurring when "molecules in a substance stay the same, both before and after".
An example he gave was that of an orange getting juiced, the molecules remain the same before juicing, and after.
what is distance
who knows pls ASAP
Answer: an amount of space between two things or people.
Explanation: hope this helps? :)
The great French chemist Antoine Lavoisier discovered the Law of Conservation of Mass in part by doing a famous experiment in 1775. In this experiment Lavoisier found that mercury(II) oxide, when heated, decomposed into liquid mercury and an invisible and previously unknown substance: oxygen gas.
Required:
a. Write a balanced chemical equation, including physical state symbols, decomposition of solild mercurytl) oxide (HgO) into liquid mercury and gaseous dioxygen.
b. Suppose 73.0 mL. of dioxygen gas are produced by this reaction, at a temperature of 130.0 °C and pressure of exactly 1 atm. Calculate the mass of mercury() oxide that must have reacted.
Answer:
a. 2 HgO(s) ⇒ 2 Hg(l) + O₂(g)
b. 0.957 g
Explanation:
Step 1: Write the balanced equation
2 HgO(s) ⇒ 2 Hg(l) + O₂(g)
Step 2: Convert 130.0 °C to Kelvin
We will use the following expression.
K = °C + 273.15
K = 130.0°C + 273.15
K = 403.2 K
Step 3: Calculate the moles of O₂
We will use the ideal gas equation.
P × V = n × R × T
n = P × V/R × T
n = 1 atm × 0.0730 L/0.0821 atm.L/mol.K × 403.2 K
n = 2.21 × 10⁻³ mol
Step 4: Calculate the moles of HgO that produced 2.21 × 10⁻³ moles of O₂
The molar ratio of HgO to O₂ is 2:1. The moles of HgO required are 2/1 × 2.21 × 10⁻³ mol = 4.42 × 10⁻³ mol.
Step 5: Calculate the mass corresponding to 4.42 × 10⁻³ moles of HgO
The molar mass of HgO is 216.59 g/mol.
4.42 × 10⁻³ mol × 216.59 g/mol = 0.957 g
What is the
Electronegativity of sugar
The electronegativity of sugar molecule is the the ability of an atom to attract an electron pair towards itself which is shared with another atom in a chemical bond.
What is electronegativity?Electronegativity is defined as the ability of an atom to attract an electron pair towards itself when share an electron or electrons with another atom in a chemical bond.
This electronegativity occurs between the atoms which made covalent bond with one another. Sugars also contain covalent bonds because all the covalent bonds in sugar molecules arise as a result of electron sharing between the atoms.
Learn more about covalent bond here: https://brainly.com/question/12732708
What kinds of minerals do you think are in a cell phone?
Answer:
Most likely phosphorus, antimony, arsenic, boron, indium or gallium. The wiring is composed mainly of copper, gold, and silver.
A container of carbon dioxide has a volume of 220.0 cm3 at a temperature of 26.0 °C. If the pressure remains constant, what is the volume at 47.0 °C?
Answer:
235.45 cm³
Explanation:
From the question given above, the following data were obtained:
Initial volume (V₁) = 220 cm³
Initial temperature (T₁) = 26 °C
Final temperature (T₂) = 47 °C
Pressure = constant
Final volume (V₂) =?
Next, we shall convert celsius temperature to Kelvin temperature. This can be obtained as follow:
T(K) = T(°C) + 273
Initial temperature (T₁) = 26 °C
Initial temperature (T₁) = 26 °C + 273
Initial temperature (T₁) = 299 K
Final temperature (T₂) = 47 °C
Final temperature (T₂) = 47 °C + 273
Final temperature (T₂) = 320 K
Finally, we shall determine the volume (i.e V₂) at 47 °C as follow:
Initial volume (V₁) = 220 cm³
Initial temperature (T₁) = 299 K
Final temperature (T₂) = 320 K
Final volume (V₂) =?
V₁ / T₁ = V₂ / T₂
220 / 299 = V₂ / 320
Cross multiply
299 × V₂ = 220 × 320
299 × V₂ = 70400
Divide both side by 299
V₂ = 70400 / 299
V₂ = 235.45 cm³
Thus, the volume at 47 °C is 235.45 cm³
please help me :)
20 points + :)
Answer:
6. valence, 7. full outer shell, 8.8, 9.lose/gain, 10. share, 11. ionic, 12. covalent, 13. ions, 14, negative
Explanation:
Answer:
6)Valence
7)stability
8)2
9)transfer of
10)share
11)covalent
12)ionic
13)ion
14)negative
9) All elements can be sorted into 3 simple groups:
O metals, meteors, meteorites
O metals, non-metals, metalloids
O medals, non-metals, meteorites
Answer: B) metals, non-metals, metalloids
An example of a metal is iron. A non-metal example is oxygen, which is a gas at STP (standard temperature and pressure).
A metalloid is a bit of a mix between a metal and non-metal element. It's sorta like an element that has both properties of metals and non-metals, or it's in a murky gray area. An example of a metalloid would be silicon.
What is the common name for the slow reaction between oxygen and iron?
A. explosion
B. rust
C. rain
Which line of defense includes active immunity?
•first
•second
•third
•fourth
Hurry up please
Answer:
B is the answer.
Explanation:
Can i have Brainliest
What is water in the form of a gas called?
Answer:
Vapor
Explanation:
Water can occur in three states: solid (ice), liquid, or gas (vapor). ... Water as a gas—vapor is always present in the air around us. You cannot see it. When you boil water, the water changes from a liquid to a gas or water vapor. As some of the water vapor cools, we see it as a small cloud called steam.
Water in the form of a gas is called water vapor. Water vapor refers to the gaseous form of water. It is created when liquid water evaporates or when solid ice sublimates directly into the gas phase
What is water in the form of a gas called?Water vapor is when water turns into gas. This happens when water turns into a gas without becoming a liquid first.
When water molecules get enough energy, their forces between each other become weaker, and they break away from the liquid phase to become water vapor in the gas phase. This happens at any temperature above the point where water turns into steam, which is 100 degrees Celsius (212 degrees Fahrenheit) when the air pressure is normal.
Read more about water here:
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During the phosphatase experiment you will use a 1% w/v of phenolphthalein di-phosphate (PPP). How much PPP do you need to make 750ml of the solution if you only have 25g and you know that the MW of PPP is 478 g/mole
Answer:
Explanation:
1 % w/v of phenolphthalein di-phosphate (PPP)
will contain 1 gram of phenolphthalein di-phosphate (PPP) in 100 mL of solution
750 mL solution will contain 7.5 g of PPP
750 mL solution will contain 7.5 / 478 moles of PPP
750 mL solution will contain .0157 moles of PPP
So 7.5 g of PPP or .0157 mole of PPP will be needed .
if a solid dissolves into a liquid, what does it mean about the properties of its molecules? Describe what it would look like on the nanoscale.
Polar solute dissolve in polar solvent and non polar solute dissolve in non polar solvent. Therefore, when any solute dissolves in a solvent, then the nature of solute and solvent is same.
What is solubility?Solubility shows the extent of solubility of a solute in solvent to make a solution. Solute is substances that is present in small amount. solvent is a substance that is present in large amount. Its SI unit is gram per litre or g/L.
Bond strength affect the solubility of a solute in solvent. weaker the bond strength is, more the solubility is. The weaker bond can be easily broken by water molecule.
Polar solute dissolve in polar solvent and non polar solute dissolve in non polar solvent. when any solute dissolves in a solvent, then the nature of solute and solvent is same.
Therefore, when any solute dissolves in a solvent, then the nature of solute and solvent is same.
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Sir Isaac Newton's only discovery was the three laws of motion
Answer:
No.
Explanation:
He also created a telescope and formula for universal gravity.
