Answer:
ΔHreaction (KJ) = - 78 KJ
The value may vary in relation to the source of the bond enthalpy data.
Bond enthalpies used (From a table of bond enthalpies )
Bond KJ/ mol
C≡O 1080
C-Cl 330
C=O 741
Cl-Cl 243
Explanation:
CO(g) + Cl2(g) → COCl2(g)
1) Lewis structures
Valence electrons
C 4
O 6
Cl 7
Reactants
CO(g)
In the case of CO, carbon has a negative charge and oxygen a positive charge.
Cl2(g)
Products
COCl2(g)
_______________________
ΔHreaction (KJ) = ∑ n* ΔH ( reactants) - ∑ n* ΔH (product)
ΔHreaction (KJ) = (ΔHC≡O + ΔHCl-Cl) - ( ΔHC=O + 2* ΔHC-Cl)
Replacing the values
ΔHreaction (KJ) = (1080 + 243) - ( 741 + 2* 330)
ΔHreaction (KJ) = 1323 - 1401
= - 78 KJ
Ms. Fremont spent last weekend grading tests . If she spent 4 min on each test , how many hours did it take her to grade all 74 tests ?
Answer:
about 5 hours
Explanation:
When doing this problem you mmust mulitiply 4 x 74 and divide the answer by 60 because 60=1 hour.
How many moles are present when there are 1.00 * 10 to the 26 power
Answer:
166.11 mol
Explanation:
I hope you mean molecules
1 mol of anything is 6.02 * 10^23
x mol of anything is 1 * 10^26
1/x = 6.02 * 10^23/1 * 10^26 Cross multiply
1 * 1*10^26 = 6.02*10^23 * x Divide by 6.02*10^23
1*10^26/6.02 * 10^23 = x
x = 166.11 mol
PLEASE HELP!!! I will mark brainliest I am really struggling with these problems
Answer:
21883.75 Joules are required to melt the ice!
which wet land is known for the large trees in the water known as bottomland hardwoods?
A. Central Texas
B.South Texas
C. East texas
A cylinder contains hydrogen gas at 20 atm. How many balloons of 500 ml capacity can be filled up completely from the gas cylinder at the external atmospheric pressure of 640 mm of Hg at constant temperature? The volume of empty cylinder is 20 liters.
Answer:
950 balloons
Explanation:
P1 = pressure inside cylinder = 20atm
P2 = pressure outside = 640mmhg = 0.842105 atm
V1= volume of cylinder =20L = 20,000 ml
V2 = volume of a single balloon= 500ml
n = number of balloons
[tex]P_{1}V_{1} =n P_{2}V_{2}\\20* 20000 =n 0.842105 * 500\\n = 950.[/tex]
Answer correctly please
Answer:
C.
Explanation:
A chemistry student is given 3.00 L of a clear aqueous solution at 17 C . He is told an unknown amount of a certain compound X is dissolved in the solution. The student allows the solution to cool to 17 C . The solution remains clear. He then evaporates all of the water under vacuum. A precipitate remains. The student washes, dries and weighs the precipitate. It weighs 0.15 kg . Using the above information can you calculate the solubility, X, in water at 17 C.
Answer:
The right approach is "50 g/l".
Explanation:
The given values are:
Mass or solute or precipitation,
= 0.15 kg
on converting it into "g", we get
= [tex]0.15 \ kg\times \frac{1000 \ g}{1 \ kg}[/tex]
= [tex]150 \ g[/tex]
Volume of solution,
= 3.00 L
Now,
The solubility of X will be:
= [tex]\frac{Mass \ of \ X}{Volume \ of \ solution}[/tex]
On substituting the values, we get
= [tex]\frac{150}{3}[/tex]
= [tex]50 \ g /l[/tex]
What is the percent of C in
CO2?
(C = 12.01 amu, O = 16.00 amu)
[? ]%
Please help
Answer:0.034%
Explanation:
A dunk tank holds 550,200 grams of water. How many moles of water are in the tank?
Answer:
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Explanation:
Which equation is correct if the
volume of a block is 64 cm3?
A. 5 cm x 5 cm x 5 cm = 64 cm3
B. 8 cm x 4 cm x 2 cm = 64 cm3
C. 5 cm + 5 cm + 5 cm = 64 cm3
D. 8 cm + 4 cm + 2 cm = 64 cm3
Answer:
B.
Explanation:
it's B because 4 x 2 is 8 and we all know 8 x 8 is 64. So the answer is B.
The equation that is correct if the volume of a block is 64 cm³ is 8 cm x 4 cm x 2 cm = 64 cm³. The correct option is B.
What is volume?Volume is the space occupied by any three-dimensional object. The volume is also considered as the total weight of the object. The volume is calculated as mass is divided by the density.
A block will be a rectangle because it contains length, breadth, and height. The formula will be V = L x B x H
As take all the options, and multiply them, we can calculate the actual volume of the box;
5 cm x 5 cm x 5 cm = 125
8 cm x 4 cm x 2 cm = 64 cm3
5 cm + 5 cm + 5 cm = 15
8 cm + 4 cm + 2 cm = 14
So, the correct option will be B, 8 cm x 4 cm x 2 cm = 64 cm. All others are incorrect.
Thus, the correct option is B. 8 cm x 4 cm x 2 cm = 64 cm.
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what does dry ashing mean
Question 5
Complete the following analogy:
Reflection nebulae : blue :: emission nebula:
Greenish-blue
Yellow
Red
Pinkish-red
Answer:
That one is tricky but i would say yellow
Explanation:
In an electrical circuit, the presence of a resistor limits the current and prevents
damage related to short circuits.
True or
False
Someone please help me
Answer:
D - synapse
Explanation:
Synapse, also called neuronal junction, the site of transmission of electric nerve impulses between two nerve cells (neurons) or between a neuron and a gland or muscle cell (effector). A synaptic connection between a neuron and a muscle cell is called a neuromuscular junction.
The acceleration of a baseball after it is hit by a bat depends on the mass of the ball and the net force on the ball. This example best illustrates which law?
a
Newton's law of universal gravitation.
b
Newton's first law of motion.
c
Newton's third law of motion.
d
Newton's second law of motion.
What are the two types of bonding we have studied?
a. Metallic and covalent
b. Covalent and ionic
c. lonic and metallic
d. Molecular and metallic
Which statement is completely accurate? O Atoms of the same element always have different numbers of neutrons. O Atoms of the same element can have neutrons but exist without protons. O Atoms of the same element always have different atomic weights. O Atoms of the same element can have different numbers of neutrons.
Answer: last one is right
Explanation: atoms of same element have always same number of protons but may have several isotopes which have different number of neutrons.
The daily dose for aspirin recommended by doctors is 81 mg/ day to reduce heart disease. a) In a week how many milligrams are administered? b) Convert the "weekly "milligrams to grams.
Answer:
a)567mg
b)0.567 grams
Explanation:
There are 7 days in a week, so we multiply the number of weeks by the number of daily dosage.
81mg*7=567mg
1 gram is 1000 mg
we divide 567 by 1000 to get the value in grams
What is the relative atomic mass of an element
whose isotopic composition is 90% of 20x and 10% of 22x
Answer:
20.2 amu.
Explanation:
Let A represent isotope ²⁰X
Let B represent isotope ²²X
From the question given above, the following data were obtained:
For Isotope A (²⁰X):
Mass of A = 20
Abundance (A%) = 90%
For Isotope B (²²X):
Mass of B = 22
Abundance (A%) = 10%
Relative atomic mass (RAM) =?
The relative atomic mass (RAM) of the element can be obtained as follow:
RAM = [(Mass of A × A%)/100] + [(Mass of B × B%)/100]
RAM = [(20 × 90)/100] + [(22 × 10)/100]
RAM = 18 + 2.2
RAM = 20.2 amu
Thus, relative atomic mass (RAM) of the element is 20.2 amu
What are the two types of bonding we have studied?
a. Metallic and covalent
b. Covalent and ionic
c. lonic and metallic
d. Molecular and metallic
Answer:
B: Covalent bond and Ionic bond
A lab requires 3.50L of a 2.0M solution of HCl. What volume of a 6.0M solution is needed to make this solution?
Answer:
THE ANSWER IS 1.167L
Explanation:
A balloon originally has 0.100 moles of helium and has a volume of 0.500 L. If 0.590 grams of He are added to the balloon, what will the new volume be, in L? (Assume temperature and pressure do not change.)
Answer:
1.24 L
Explanation:
Avogadro's Law
[tex]\frac{V_{1} }{n_{1} } = \frac{V_{2} }{n_{2} }[/tex]
Convert 0.590 g of He to moles.
0.590 g x (1 mol/4.00 g) = 0.1475 mol He
Add 0.1475 mol to 0.100 mol since the initial moles (n1) increases by this amount.
0.100 mol + 0.1475 mol = 0.2475 mol He
This will represent the final moles (n2)
The initial volume is given, 0.500 L. Plug in the values.
[tex]\frac{0.500 L}{0.100 mol} = \frac{V_{2} }{0.2465 mol}[/tex]
[tex]V_{2} = \frac{(0.500 L)(0.2475 mol)}{(0.100 mol)} \\V_{2} = 1.2375\\V_{2} = 1.24 L[/tex]
Taking into account the Avogadro's law, the new volume will be 1.24 L.
Avogadro's law establishes the relationship between the amount of gas and its volume when the temperature and pressure are held constant. Remember that the amount of gas is measured in moles.
This law states that constant pressure and temperature, the same amount of gas has the same volume regardless of the chemical element that forms it.
On the other hand, Avogadro's law establishes that the volume is directly proportional to the quantity of gas: if the quantity of gas increases, the volume will increase; whereas if the amount of gas decreases, the volume decreases.
Mathematically, this law states that the ratio between the volume and the quantity of gas is constant:
[tex]\frac{V}{n} =k[/tex]
Assuming that you have an initial state 1 and the conditions are modified to a final state 2, it is true:
[tex]\frac{V1}{n1} =\frac{V2}{n2}[/tex]
In this case, being the molar mass of He 4 g/mole, 0.590 grams of He are contained in the following amount of moles:
[tex]0.590 gramsx\frac{1 mole}{4 grams} =0.1475 moles[/tex]
Then, you know:
V1= 0.500 Ln1= 0.100 molesV2= ?n2= 0.100 mol + 0.1475 mol = 0.2475 mol He because 0.590 grams are added, this is 0.1475 moles, of He to the balloonReplacing in Avogadro's Law:
[tex]\frac{0.500 L}{0.100 moles} =\frac{V2}{0.2475 moles}[/tex]
Solving:
[tex]V2=0.2475 molesx\frac{0.500 L}{0.100 moles}[/tex]
V2= 1.2375 L≅ 1.24 L
Finally, the new volume will be 1.24 L.
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Explanation:
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Cars are the leading cause of____
1. carbon dioxide
2. nitrogen oxide
3.carbon monoxide
pollution
Answer:
nitrogen oxide
Explanation:
Calculate the pH for the following weak acids
.01M Formic acid (HCHO2) aka= 1.7 x 10^-4
Answer:
pH = 2.88
Explanation:
For a weak acid solution, the pH can be calculated using the following formulas:
[H⁺] = [tex]\sqrt{Ka*C}[/tex]pH = -log[H⁺]Where Ka = [tex]10^{-pKa}[/tex] and C is the molar concentration.
We are given Ka and C by the problem, meaning we can now proceed to calculate [H⁺]:
[H⁺] = [tex]\sqrt{1.7*10^{-4}*0.01}[/tex] [H⁺] = 0.0013 MFinally we calculate the pH:
pH = - log (0.0013) = 2.88PLEASE HELP!
A piece of metal is heated to a temperature of 50.0°C and then placed in a calorimeter containing 50.0 g of water at 27.0°C. The water temperature increases to 35.0°C. How many joules of heat were transferred from the metal to the water? (Cwater = 4.18J/g•°C)
Answer: 1672 Joules
Explanation:
The quantity of heat required to raise the temperature of a substance by one degree Celsius is called the specific heat capacity.
[tex]Q=m\times c\times \Delta T[/tex]
Q = Heat absorbed by water = ?
c = heat capacity of water = [tex]4.18 J/g^0C[/tex]
Initial temperature of the water = [tex]T_i[/tex] = [tex]27^0C[/tex]
Final temperature of the water = [tex]T_f[/tex] = [tex]35^0C[/tex]
Change in temperature ,[tex]\Delta T=T_f-T_i=(35.0-27.0)^0C=8.0^0C[/tex]
Putting in the values, we get:
[tex]Q=50.0g\times 4.18J/g^0C\times 8.0^0C=1672J[/tex]
As heat absorbed by water is equal to the heat released by metal, the Joules of heat transferred are 1672 Joules
A] 1 N2 + 3 H2 → 2 NH3
1. How many moles and grams of ammonia can be made from 6.3 moles of H2 ?
2. How many moles and particles of ammonia can be made from 2.5 moles of N2 ?
3. How many moles is 425 g of ammonia? How many moles and grams of N2 are needed to make it?
4. How many moles and grams and liters of H2 are needed to make 10 moles of ammonia?
I haven't done these in some time, so I'm not sure if they are 100% right.
1) 6.3 moles of H2( 2 mol of NH3 / 3 mol of H2)= 4.2 mol of NH3
6.3 moles of H2( 2 mol of NH3/ 3 mol of H2)(17.04 g of NH3/1 mol NH3)= 71.57 g of NH3
2) 2.5 moles of N2(2 mol of NH3/1 mol of N2)= 5 moles of NH3
2.25 moles of N2(2 mol of NH3/ 1 mol of N2)(6.02x10^23 particles/ 1 mol of NH3)= 3.01x10^24 particles of NH3
3) 425 g of NH3(1 mol of NH3/17.04 g NH3)= 24.9 moles of NH3
425 g of NH3(1 mol of NH3/17.04 g of NH3)(1 mol of N2/2 mol of NH3)(28.02 g of N2/1 mol N2)= 349 g of N2
425 g of NH3(1 mol of NH3/17.04 g of NH3)(1 mol of N2/2 mol of NH3)= 12.5 mol of N2
4) 10 moles NH3(3 moles of H2/2 moles of NH3)= 15 moles H2
10 moles NH3(3 mol of H2/2 mol of NH3)(2.02 g of H2/1 mol of H2)= 30.3 g of H2
30.3 g = .0303 liters of H2
How many moles of water are produced from burning 80 moles of
methane in excess oxygen?
Answer:
160 mol H₂O
Explanation:
Step 1: Write the balanced complete combustion reaction
CH₄ + 2 O₂ ⇒ CO₂ + 2 H₂O
Step 2: Establish the appropriate molar ratio
According to the balanced equation, the molar ratio of CH₄ to H₂O is 1:2.
Step 3: Calculate the moles of water formed from 80 moles of methane
We will use the previously established molar ratio.
80 mol CH₄ × 2 mol H₂O/1 mol CH₄ = 160 mol H₂O
What volume, in milliliters, of water is needed to make an 8.40 M solution of HCl acid using 180. grams of HCI ?
0 603 mL
O 41.4 mL
0 587 ml
0 24.1 mL
Answer:
0 587 mL
Explanation:
First we convert 180 grams of HCl into moles, using its molar mass:
180 g ÷ 36.46 g/mol = 4.94 mol HClNow we can use the number of moles and the given concentration to calculate the required volume, applying the definition of molarity:
Molarity = moles / litersLiters = Moles / molarity4.94 mol / 8.40 M = 0.588 LFinally we convert liters into milliliters:
0.588 L * 1000 = 588 mLThe closest answer is option C, 587 mL.
The volume needed to make an 8.40 M solution of HCl is 0.587 ml.
The correct option is C.
What is HCl?HCl is a strong acid. It is present in our stomach to help in digesting food.
Step1: covert 180 grams into moles
Molar mass of HCl is 36.46 g
[tex]\dfrac{180 g}{36.46 g/mol } = 4.94\; mol\; HCl[/tex]
Step2: calculate the molarity
[tex]\rm Molality = \dfrac{mol}{L}\\\\\rm L = \dfrac{4.94 mol }{8.40 M} = 0.588 L\\[/tex]
Covert the liters into ml
[tex]\dfrac{0.588 L}{1000} = 588 mL[/tex]
Thus, the volume of the solution is 588 ml., nearest is option C, 587 ml.
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Raw milk is stored at a dairy farm in a refrigerated cylindrical vat 6.50 feet wide and 12.5 feet high. If the vat contains 3.3 × 10² ft³ of milk, how many kg of milk does the vat contain, given that raw milk has a density of 1030 kg/m3?
Answer:
11.02 kg kg
Explanation:
From the question,
Density = Mass/Volume
D = m/v.................. Equation 1
Let D = Density of milk in the vat, m = mass of the milk in the vat, v = volume of the milk in the vat.
Make m the subject of the equation
m = D/v................ Equation 2
Given: D = 1030 kg/m³, v = 3.3×10² ft³ = 330×0.2832 = 93.456 m²
Substitute these values into equation 4
m = 1030/93.456
m = 11.02 kg
Density is the mass of the substance present in the unit of the volume or can be said to be equal to the ratio of the mass and the volume of the given substance or object.
31,576.71 kg of milk is present in the vat.
How to calculate the mass of the milk?Given,
Density = [tex]1030\rm \; kg/m^{3}[/tex]Volume (V) = [tex]3.3\times 10^{2} \;\rm ft^{3}[/tex]The volume in cubic feet will be converted in [tex]\rm m^{2}[/tex] as,
1 cubic feet = 0.0929 [tex]\rm m^{2}[/tex]
[tex]\begin{aligned}\rm V &= 330 \times 0.0929 \\\rm V &= 30.657\;\rm m^{2}\end{aligned}[/tex]
The formula for calculating mass form density and volume is:
[tex]\begin{aligned}\;\rm Mass (m) &= \rm Density \times Volume (V)\\\\\rm m &= 1030 \rm kg/m^{3} \times 30.657\rm m^{2}\\\\\rm m &= 31,576.71 \rm kg \end{aligned}[/tex]
Therefore, 31,576.71 kg is the mass.
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