Answer:
Answer: 1) 155.65 kJ; 2) -59.0 kJ/mol; 3) a)
Step-by-step explanation:
Answer on Question # 55533 - Chemistry - General chemistry
Question:
1. Given the data. N2(g) + O2(g) = 2 NO(g) ΔH = +180.7 kJ; 2 NO(g) + O2(g) = 2 NO2(g) ΔH = −113.1
kJ; 2 N2O(g) = 2 N2(g) + O2(g) ΔH = − 163.2 kJ; Use Hess’s Law to calculate ΔH for the reaction
N2O(g) + NO2(g) = 3 NO(g); Show your work.
2. Calcium carbide (CaC2) reacts with water to form acetylene (C2H2) and Ca(OH)2. From the
following enthalpy of reaction data and data in Appendix C in textbook, calculate ΔHf° for CaC2(s):
CaC2(s) + 2 H2O(l) Ca(OH)2(s) + C2H2 (g) ΔH = −127.2kJ
3. Using average bond enthalpies, predict which of the following reactions will be most
exothermic: a) C(g) + 2 F2(g) CF4(g) b) CO(g) +3 F2(g) CF4(g) + OF2(g) c) CO2(g) + 4 F2(g) CF4(g) +
2 OF2(g)
Solution
1)
N2(g) + O2(g) = 2 NO(g) ΔH1 = +180.7 kJ x(+2)
2 NO(g) + O2(g) = 2 NO2(g) ΔH2 = −113.1 kJ x(-1)
2 N2O(g) = 2 N2(g) + O2(g) ΔH3 = − 163.2 kJ x(+1)
2N2O(g) + 2NO2(g) = 6 NO(g) ΔH = (ΔH3 + 2ΔH1 – ΔH2)
N2O(g) + NO2(g) = 3 NO(g) ΔH = (ΔH3 + 2ΔH1 – ΔH2)/2 = 155.65 kJ
2)
CaC2(s) + 2 H2O(l) = Ca(OH)2(s) + C2H2 (g) ΔHrxn = −127.2kJ
ΔHrxn = ΔHf°(C2H2) + ΔHf°(Ca(OH)2) - 2ΔHf°(H2O) - ΔHf°(CaC2);
ΔHf°(CaC2) = ΔHf°(C2H2) + ΔHf°(Ca(OH)2) - 2ΔHf°(H2O) – ΔHrxn
ΔHf°(C2H2) = 227.4 kJ/mol
ΔHf°(Ca(OH)2) = -985.2 kJ/mol
ΔHf°(H2O) = -285.8 kJ/mol
ΔHf°(CaC2) =227.4 - 985.2 + 2x285.8 + 127.2 = -59.0 kJ/mol
3)
a) C(g) + 2 F2(g) = CF4(g)
b) CO(g) +3 F2(g) = CF4(g) + OF2(g)
c) CO2(g) + 4 F2(g) = CF4(g) + 2 OF2(g)
C-F bond enthalpy 440 kJ/mol
C=O bond enthalpy in carbon dioxide 805 kJ/mol
C=O bond enthalpy in carbon monoxide 1077 kJ/mol
O-F bond enthalpy 184 kJ/mol
F-F bond enthalpy 153 kJ/mol
a) ΔHrxn = 2x153 - 4x440 = -1454 kJ – the most exothermic
b) ΔHrxn = 1077 + 3x152 - 2x184 - 4x440 = -595 kJ
c) ΔHrxn =805x2 + 4x153 - 4x440 – 2x2x184 = -274 kJ
The world record for the largest collection of bookmarks is 71 235 bookmarks. Find the closest benchmark for each: a) in thousands _______________ b) in hundreds _______________ c) in tens _______________
Answer:
A: 71,235,000
B: 71,235,00
C: 71,240
Step-by-step explanation: Round by thousands, hundreds and tens.
2. in a geometric progression
the first term is 64 and the
fourth term is 27. Calculate
(a) the common ratio
Answer:
0.75 or 3/4
Step-by-step explanation:
If we call the common ratio r, since 4 - 1 = 3 we can write:
64 * r³ = 27
r³ = 27/64
r = ∛(27/64) = ∛27 / ∛64 = 3 / 4
Answer:
(a) the common ratio = 3/4.
Step-by-step explanation:
First term a1 = 64
The fourth term a4 = a1 r^3 = 27
So a1 r^3 / a1 = 27/64
r^3 = (27/64)
r = ∛ (27/64
= 3/4.
What is the height of the prsim if there is 3 meters,2 meters, and the volume is 36 cublic meters
Answer: The height is 6 meters
Step-by-step explanation:
3 * 2 *h = 36 where h is the height
6h = 36
h = 6
Answer:
The answer is 6
Step-by-step explanation:
Because you would have to get 6h=36 alone so you would have to divide 6 by both sides. which gives you h=6
Please help i will mark brainliest
Answer:
y=-6x+1
Step-by-step explanation:
Simplify this expression: 19 - (-8) - (-14) = ? A. 41 B. 25 C. -7 D. -3
Answer:
A. 41
Step-by-step explanation:
19 - (-8) - (-14) =
19+8+14
Remember: Two negatives=One positive ;)
27+14
41
A. 41
Answer:
[tex]\mathrm{A.} \: 41[/tex]
Step-by-step explanation:
[tex]19 - (-8) - (-14)[/tex]
[tex]\mathrm{Apply \: rule:} \: -(-a)=a[/tex]
[tex]19+8+14[/tex]
[tex]\mathrm{Add \: the \: numbers.}[/tex]
[tex]=41[/tex]
Work out x. Give reasons for your answer.
Answer:
The measurement for x is 80°
Step-by-step explanation:
In the picture, we see two parallel lines cut by a transversal line. Since the lines are cut by a transversal, then there are a few things we should know that can help us find the value of x.
Corresponding angles are congruent. Angles that are right beside each other (such as ∠CBD and ∠CBA) are a linear pair. This means that they have a total measurement of 180° when added together.Now that we know these things, we can use this information to find the measurement of ∠CBA. We do this by subtracting 100 from 180 because ∠CBA and ∠CBD are a linear pair. Once we know the measurement of this angle, then it will be much easier to find the value of x.
180 - 100 = 80
So, the measurement of ∠CBA is 80°. Now, ∠CBA and ∠x are corresponding angles so this means that they have the same measurements. If the measurement of ∠CBA is 80°, then the measurement of ∠x is also 80°
x = 80°
the area of a rectangular sandbox can be expressed as 72xy + 18x the width of the sandbox is 9x what is the perimeter of the sandbox
Answer:
18x +16y +4
Step-by-step explanation:
The area is the product of length and width, so the length is ...
A = LW
L = A/W = (72xy +18x)/(9x) = 8y +2
The perimeter is double the sum of length and width:
P = 2(L +W) = 2(8y +2 +9x)
P = 18x +16y +4 . . . . the perimeter of the sandbox
Dawn is going scuba diving. Which situation would be modeled by a positive number?
Answer:
on the dive boat deck
Step-by-step explanation:
Answer:
the above is right
Step-by-step explanation:
In a game the average score was 60 time score was 5/2 of the average what was Tim’s score?
Answer:
in my own reasoning not sure if I am correct
Step-by-step explanation:
first it said Tim score was 5/2 of the of the average score
and the average score is 60
so that will be 5/2 × 60 which is
= 150
HELP MEEEEE PLEASEEEEE SOMEONE!!
Answer:
A
Step-by-step explanation:
the triangles share one angle and they have two equal sides
ILL MARK YOU BRAINLIEST :))))) if you apply the changes below to the linear parent function, f(x)=|x|, what is the equation of the new function Shift 4 units left Shift 2 units up
Answer:
f(x) = |x + 4| + 2.
Step-by-step explanation:
When you shift the function to the left, the x-value changes, so you put the change within the absolute value. Also, within the absolute value, when you shift things to the right, you minus, and when you shift to the left, you add.
When you shift the function up, the y-value changes, so you put the changes outside of the absolute value. Shifting up means adding and shifting down means subtracting.
Hope this helps!
Is this function linear or nonlinear y=1/2x^{2}
will give brainliest
Answer:
nonlinear
Step-by-step explanation:
The word 'linear' means something having to do with a line. On a Cartesian Plane, a linear characteristic is a feature wherein the graph is a straight line. The line can cross in any direction, but it's always an instant line. A non-linear function has a shape that isn't an immediate line
The graph is nonlinear because it is not a straight line.
please mark me brainliest!
Answer:
Nonlinear.
Step-by-step explanation:
Since x is being squared, the equation is actually a parabola. The power of x has to be 1 for the function to be a linear function, so this equation is nonlinear.
Hope this helps!
Which statement is true regarding the graphed functions?
A. f(4) = g(4)
B. f(4) = g(-2)
C. f(2) = g(-2)
D. f(-2) = g(-2)
Answer:c. F(2)=g(-2)
Step-by-step explanation:
One week, London earned $313.50 at her job when she worked for 15 hours. If she is paid the same hourly wage, how many hours would she have to work the next week to earn $647.90 ?
Answer:
31hr
Step-by-step explanation:
Find the value of:[(1/4)-1 + (1/3)-2 - (1/2)-3 ] ÷ 52
Answer:
-71/624
Step-by-step explanation:
Easiest and fastest way to do this is to plug it into you calc. If you are doing it by hand, remember BPEMDAS and convert the fractions into same denominators to make adding easier.
Use the distributive property to multiply -3(-28)
Answer:
84
Step-by-step explanation:
-3 multiplied by -28 equals 84. The two negatives cancel out.
Answer: ur answer would be 84
-3*-28
84
Answer this question
Answer: a.) (3x +1)(2x +3)
Step-by-step explanation:
The factors that work to get the middle term, 11x, are 3×3x = 9x and 1×2x=2x. 2x +9x = 11x
82 Find the circumference
of a circle with a radius
of 10cm.
A. 6.28 m
B. 62.8m
C. 628m
D. 6280m
Answer:
0.628 m (This is the correct answer but I cant find it in your options)
Step-by-step explanation:
Radius = 10 cm = 0.1 m
Now, The circumference:
=> Circumference = [tex]2\pi r[/tex]
=> C = 2(3.14)(0.1)
=> C = 0.628 m
Answer:
B. 62.8m
Step-by-step explanation:
C= 2πr= 2*3.14* 10 m= 62.8 m
Assumed radius is 10 m as the answer options are in metre
Find five rational numbers between 2/3and4/5
Answer:
61 / 90, 62 /90, 63 /90, 64/90, 65/90
Explanation:
2/3 = 2 x 5 / 3 x 5
= 10 / 15
4/5 = 4 x 3 / 5 x 3
12 / 15
we can find 5 rational numbers betwen 2/3 and 4/5 by multiplying them with 5 + 1 = 6
10 / 15 X 6 /6
= 60 / 90
12/ 15 X 6 /6
= 72 / 90
the rational numbers = 61 / 90 62 /90 63 /90 64/90 65/90
Answer:
31/45, 32/45, 11/15, 34/35, 7/9.
Step-by-step explanation:
The LCM of 3 and 5 is 15 so we can write 2/3 and 4/5 as:
10/15 and 12/15 so one rational number between these is 11/15.
Now 11/15 = 33/45 and 4/5 = 36/45
So 2 rationals between these are 34/45 and 35/45 = 7/9
2/3 = 30 /45 and 11/15 = 33/45
so 2 rationals between these are 31/45 and 32/45.
Using side lengths only, could the triangles be similar? Triangle X Y Z. Side X Y is 1.5, X Z is 1, Z Y is 2. Triangle Q S R. Side Q R is 1, R S is 1.5, S Q is 0.5.
Answer:
no
Step-by-step explanation:
In ∆XYZ, we can write the ratios of the sides from shortest to longest as ...
y : z : x = 1 : 1.5 : 2 = 2 : 3 : 4
In ∆QSR, we can write the ratios of the side lengths from shortest to longest as ...
r : s : q = 0.5 : 1 : 1.5 = 1 : 2 : 3
Based on side lengths only, the triangles cannot be similar.
__
Additional note
Even if shortest-to-longest side ratios were the same, the triangle naming is incorrect for them to be similar.
Which step is the same in the construction of parallel lines and the construction of a perpendicular line to a point off a line?
Answer:
Both types of lines are built on the same plane although they meet different objectives for which they are built.
Step-by-step explanation:
The difference is that in the case of parallel lines they will never cross and in the case of perpendicular lines if they cross each other, which can give rise to the formation of right angles to each other.
is 1.25 the same as 25%?
Answer:
No
Step-by-step explanation:
1.25 as a percentage is 125%.
25% as a decimal is 0.25.
Which expression is equivalent to
Answer:
Option 2) [tex]x^{\frac{1}{8}}y^8[/tex]
Step-by-step explanation:
=> [tex](x^{\frac{1}{4} } y ^{16} )^\frac{1}{2}[/tex]
=> [tex]x^{\frac{1}{4} * \frac{1}{2} } * y ^{16*\frac{1}{2} }[/tex]
=> [tex]x^{\frac{1}{8}}y^8[/tex]
arcs and circles formula? can someone help me find the answer?
Answer:
9.2 cmHere,
The length of an arc of a sector with theta nag radius'r' is:
[tex] \frac{theta}{360} 2\pi \: r[/tex]
CD=?
Radius=7.9 cm
theta=66.4
Length of CD
[tex] \frac{66.4}{360} \times 2 \times \pi \times 7.9 \\ = \frac{66.4}{360} \times 2 \times 3.14 \times 7.9 \\ = 9.1506 \\ = 9.2 \: cm[/tex]
Hope this helps...
Good luck on your assignment..
The graph below shows a line of best fit for data collected on the number of toys sold at a toy store since the opening of the store. Based on the line of best fit, how many toys were sold 13 days after the store opened?
A.) 195
B.) 260
C.) 325
D.) 130
The answer that line of best fit, how many toys were sold 13 days after the store opened is A.) 195
SOMEBODY HELPPP PLEASEEEE. I don’t understand
Answer:
a) 18
b) 10
c) x^2 - 4x + 5
d) 4x^2 + 2
Step-by-step explanation:
f(x) = 4x - 2
g(x) = x^2 + 1
a) f(5) = 4(5) - 2 = 20 - 2 = 18.
b) g(-3) = (-3)^2 + 1 = 9 + 1 = 10.
c) g(x - 2)...
g(x - 2) = (x - 2)^2 + 1 = x^2 - 2x - 2x + 4 + 1 = x^2 - 4x + 5.
d) f(g(x)) = f(x^2 + 1) = 4(x^2 + 1) - 2 = 4x^2 + 4 - 2 = 4x^2 + 2.
Hope this helps!
What is the parametric form of the line r = (2, -3, 0) + t(1, 0, -1)?
Answer:
d
Step-by-step explanation:
(x,y,z)=(2,-3,0)+t(1,0,-1)
(x,y,z)=(2,-3,0)+(t,0,-t)
(x,y,z)=(2+t,-3,-t)
x=2+t
y=-3
z=-t
If you don't understand, you can ask me :)
can someone please help
Answer: 57°
Step-by-step explanation:
Bisecting makes angle ZXY=ZXW. So 58+58=116.
Then solve. 2x+2=116.
2x=114
x=57
Which of the following represents a rotation of triangle XYZ, which has vertices (-4,7), Y(6,2), and Z (3,-8) about the origin by 90 degrees? HELP PLS options: A: X (-7,-4) Y(6,-2) Z(-8,3) B: X(7,-4) Y(-2,6) Z (3,-8) C: X (-7,-4) Y(-2,6) Z (8,3) D: X(7,-4) Y (-2,6) Z (-3,8)
Answer:
The best option is B: X' = (-7,-4), Y' = (-2,6), Z'=(8, 3).
Step-by-step explanation:
Each vertex can be represented as a vector with regard to origin.
[tex]\vec X = -4\cdot i + 7\cdot j[/tex], [tex]\vec Y = 6\cdot i + 2\cdot j[/tex] and [tex]\vec Z = 3\cdot i -8\cdot j[/tex].
The magnitudes and directions of each vector are, respectively:
X:
[tex]\|\vec X\| = \sqrt{(-4)^{2}+7^{2}}[/tex]
[tex]\|\vec X\| \approx 8.063[/tex]
[tex]\theta_{X} = \tan^{-1}\left(\frac{7}{-4} \right)[/tex]
[tex]\theta_{X} \approx 119.744^{\circ}[/tex]
Y:
[tex]\|\vec Y\| = \sqrt{6^{2}+2^{2}}[/tex]
[tex]\|\vec Y\| \approx 6.325[/tex]
[tex]\theta_{Y} = \tan^{-1}\left(\frac{2}{6} \right)[/tex]
[tex]\theta_{Y} \approx 18.435^{\circ}[/tex]
Z:
[tex]\|\vec Z\| = \sqrt{3^{2}+(-8)^{2}}[/tex]
[tex]\|\vec Z\| \approx 8.544[/tex]
[tex]\theta_{Z} = \tan^{-1}\left(\frac{-8}{3} \right)[/tex]
[tex]\theta_{Z} \approx 290.556^{\circ}[/tex]
Now, the rotation consist is changing the direction of each vector in [tex]\pm 90^{\circ}[/tex], which means the existence of two solutions. That is:
[tex]\vec p = r \cdot [\cos (\theta \pm 90^{\circ})\cdot i + \sin (\theta \pm 90^{\circ})\cdot j][/tex]
Where [tex]r[/tex] and [tex]\theta[/tex] are the magnitude and the original angle of the vector.
Solution I ([tex]+90^{\circ}[/tex])
[tex]\vec p_{X} = 8.063\cdot [\cos (119.744^{\circ}+90^{\circ})\cdot i + \sin (119.744^{\circ}+90^{\circ})\cdot j][/tex]
[tex]\vec p_{X} = -7\cdot i -4\cdot j[/tex]
[tex]\vec p_{Y} = 6.325\cdot [\cos(18.435^{\circ}+90^{\circ})\cdot i+\sin(18.435^{\circ}+90^{\circ})\cdot j][/tex]
[tex]\vec p_{Y} = -2\cdot i +6\cdot j[/tex]
[tex]\vec p_{Z} = 8.544\cdot [\cos(290^{\circ}+90^{\circ})\cdot i +\sin(290^{\circ}+90^{\circ})\cdot j][/tex]
[tex]\vec p_{Z} = 8.029\cdot i +2.922\cdot j[/tex]
Solution II ([tex]-90^{\circ}[/tex])
[tex]\vec p_{X} = 8.063\cdot [\cos (119.744^{\circ}-90^{\circ})\cdot i + \sin (119.744^{\circ}-90^{\circ})\cdot j][/tex]
[tex]\vec p_{X} = 7\cdot i +4\cdot j[/tex]
[tex]\vec p_{Y} = 6.325\cdot [\cos(18.435^{\circ}-90^{\circ})\cdot i+\sin(18.435^{\circ}-90^{\circ})\cdot j][/tex]
[tex]\vec p_{Y} = 2\cdot i -6\cdot j[/tex]
[tex]\vec p_{Z} = 8.544\cdot [\cos(290^{\circ}-90^{\circ})\cdot i +\sin(290^{\circ}-90^{\circ})\cdot j][/tex]
[tex]\vec p_{Z} = -8.029\cdot i -2.922\cdot j[/tex]
The rotated vertices are: i) X' = (-7,-4), Y' = (-2,6), Z'=(8.029, 2.922) or ii) X' = (7,4), Y' = (2,-6), Z' = (-8.029, -2.922). The best option is B: X' = (-7,-4), Y' = (-2,6), Z'=(8, 3).
What is the slope of the line represented by the equation y = 5 x – 3?
0-3
4
o
5
tln m
O 3
Answer:
the slope is 5
Step-by-step explanation:
y = 5 x – 3
This equation is in slope intercept form
y = mx+b where m is the slope and b is the y intercept
the slope is 5 and the y intercept is -3
Answer:
The Slope is 5
Step-by-step explanation:
As seen in the y-intercept equation, 5x is shown as the slope of the line.