What is the entropy of this collection of training examples with respect to the positive class B. What are the information gains of A1 and A2 relative to the training dataset For A3, which is a continuous attribute, compute the information gain for every possible split. C. What is the best split (among A1,A2, and A3) according to the information gain
Answers
The data set is missing in the question. The data set is given in the attachment.
Solution :
a). In the table, there are four positive examples and give number of negative examples.
Therefore,
[tex]$P(+) = \frac{4}{9}$[/tex] and
[tex]$P(-) = \frac{5}{9}$[/tex]
The entropy of the training examples is given by :
[tex]$ -\frac{4}{9}\log_2\left(\frac{4}{9}\right)-\frac{5}{9}\log_2\left(\frac{5}{9}\right)$[/tex]
= 0.9911
b). For the attribute all the associating increments and the probability are :
[tex]$a_1$[/tex] + -
T 3 1
F 1 4
Th entropy for [tex]$a_1$[/tex] is given by :
[tex]$\frac{4}{9}[ -\frac{3}{4}\log\left(\frac{3}{4}\right)-\frac{1}{4}\log\left(\frac{1}{4}\right)]+\frac{5}{9}[ -\frac{1}{5}\log\left(\frac{1}{5}\right)-\frac{4}{5}\log\left(\frac{4}{5}\right)]$[/tex]
= 0.7616
Therefore, the information gain for [tex]$a_1$[/tex] is
0.9911 - 0.7616 = 0.2294
Similarly for the attribute [tex]$a_2$[/tex] the associating counts and the probabilities are :
[tex]$a_2$[/tex] + -
T 2 3
F 2 2
Th entropy for [tex]$a_2$[/tex] is given by :
[tex]$\frac{5}{9}[ -\frac{2}{5}\log\left(\frac{2}{5}\right)-\frac{3}{5}\log\left(\frac{3}{5}\right)]+\frac{4}{9}[ -\frac{2}{4}\log\left(\frac{2}{4}\right)-\frac{2}{4}\log\left(\frac{2}{4}\right)]$[/tex]
= 0.9839
Therefore, the information gain for [tex]$a_2$[/tex] is
0.9911 - 0.9839 = 0.0072
[tex]$a_3$[/tex] Class label split point entropy Info gain
1.0 + 2.0 0.8484 0.1427
3.0 - 3.5 0.9885 0.0026
4.0 + 4.5 0.9183 0.0728
5.0 -
5.0 - 5.5 0.9839 0.0072
6.0 + 6.5 0.9728 0.0183
7.0 +
7.0 - 7.5 0.8889 0.1022
The best split for [tex]$a_3$[/tex] observed at split point which is equal to 2.
c). From the table mention in part (b) of the information gain, we can say that [tex]$a_1$[/tex] produces the best split.
Related Questions
Which factor contributes the most to the rates of diffusion and effusion between two gases in a mixture?
a)The size of the particles.
b)The molar mass of the particles.
c)The interactions between the particles.
d)The relative volume of the particles to each other.
Answers
Answer:
b)The molar mass of the particles.
Explanation:
The rate of effusion of a gas is inversely proportional to the square root of its molar mass (Graham's law), a relationship that closely approximates the rate of diffusion. As a result, light gases tend to diffuse and effuse much more rapidly than heavier gases.
Lab: Enthalpy.
What were the learning goals of this lab experiment? Check all that apply.
to use mass and temperature data to do computations involving heat
to demonstrate that different reactions have different enthalpies
to compute a reaction’s enthalpy directly using mass measurements and a calorimeter
to compute the enthalpy of a reaction that cannot be measured directly using a simple calorimeter
Hess
’s law allows you to find the net enthalpy of the magnesium combustion by adding the enthalpies of intermediate reactions.
To find the enthalpy of a reaction in the lab, you measured the
mass
of the reactants
and the
temperature
change during the reaction.
In both Reactions 1 and 2, the temperature change was
positive
, meaning that the
reactions
gave off
heat.
Answers
Answer:
to use mass and temperature data to do computations involving heat
to compute a reaction’s enthalpy directly using mass measurements and a calorimeter
To find the enthalpy of a reaction in the lab, you measured the mass
of the reactants
and the
temperature
change during the reaction.
Explanation:
Was that good?
Enthalpy is a thermodynamic system's internal energy total as well as the volume times pressure ratio.
What is Enthalpy?Enthalpy is a property or state function that resembles energy; it has the same dimensions as energy and is therefore measured in joules or ergs. The value of enthalpy is solely dependent on the temperature, pressure, and composition of the system, not on its history.
Enthalpy, denoted by the symbol H, is the sum of the internal energy, denoted by E, and the product of the pressure and volume, denoted by PV.
The change in internal energy is equal to the heat transmitted to, less the work done by, the system, according to the law of energy conservation.
Therefore, Enthalpy is a thermodynamic system's internal energy total as well as the volume times pressure ratio.
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HELPPPP ASAP!!! Plzzz
Answers
Answer:
420 miles
Explanation:
From the question given above, the following data were obtained:
Time = 3.5 hours
Speed = 120 mi/h
Distance =?
Speed is defined as the distance travelled per unit time. Mathematically, it is expressed as:
Speed = distance / time
With the above formula, we can obtain the distance travelled by the plane as follow:
Time = 3.5 hours
Speed = 120 mi/h
Distance =?
Speed = distance / time
120 = distance / 3.5
Cross multiply
Distance = 120 × 3.5
Distance = 420 miles
Thus, the distance travelled by the plane is 420 miles
1. What volume of a 2.50M Kl(aq) is needed to make 200 ml of a 1.OOM KI)aq)?
Answers
Answer:
80 ml
Explanation:
From the question,
Applying Dilution formular
MV = mv................... Equation 1
Where M = Molarity of Kl before dilution, V = Volume of Kl before dilution, m = molarity of Kl after dilution, v = volume of Kl after dilution.
make V the subject of the equation
V = mv/M............. Equation 2
Given: m = 1.00 M, v = 200 ml, M = 2.50 M
Substitute these values into equation 2
V = (1.00×200)/2.50
V = 80 ml
Is chemistry required to get into speech language pathology?
Answers
Answer:
As of right now (4-7-2021), the physical science requirement for the SLP certificate must be met by completing coursework in the areas of either chemistry or physics.
Question 6 of 10
How much energy is required to vaporize 2 kg of gold? Use the table below
and this equation: Q = mLvapor
Substance
Latent Heat
Fusion
(melting)
(kJ/kg)
Melting
Point
(°C)
Latent Heat
Vaporization
(boiling) (kJ/kg)
Boiling
Point
(°C)
Aluminum
400
660
1100
2450
Copper
207
1083
4730
2566
Gold
628
1063
1720
2808
Helium
52
-270
21
-269
Lead
24.5
327
871
1751
Mercury
11.4
-39
296
357
Water
335
0
2256
100
Answers
Answer: Q = mlvap
Q = (2 kg)(1 kmol/197 kg)(1,000 mol/1 kmol)
Q = 10.15 kJ
2126 joules of energy in form of thermal energy is required to vaporize 2 kg of gold.
What is thermal energy?Thermal energy is defined as a type of energy which is contained within a system which is responsible for temperature rise.Heat is a type of thermal energy.It is concerned with the first law of thermodynamics.
Thermal energy arises from friction and drag.It includes the internal energy or enthalpy of a body of matter and radiation.It is related to internal energy and heat .It arises when a substance whose molecules or atoms are vibrating faster.
These vibrating molecules and atoms collide and as a result of which heat is generated in a substance , more the collision of particles , higher is the thermal energy.
Amount of heat is calculated as, Q=2×1063 =2126 joules as per the given formula.
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. Give an example of a salt that is less soluble when the temperature increases
Answers
Answer:
cerium (iii) sulfate is less soluble
Answer:
cerium sulphate is less solube when the temperature increase
Options:
1. Unsaturated fat or saturated fat
2. Fatty acids, carbohydrates, sterols, or phospholipids
3. Fatty acids, carbohydrates, or triglycerides
Please helppp
Answers
Answer:
1. saturated
2. fatty acids
3. fatty acids
Explanation:
Answer:
option 2 is correct
Explanation:
A strong acid, such as hydrochloric acid cannot be poured down a sink because it will react and dissolve the metal in the pipes. Yet a strong base, commonly found in drain cleaner, can be poured down a sink. A strong acid can be neutralized with a strong base, creating a salty water solution. What will happen when 10.0 g of hydrochloric acid were mixed with 10.5 grams of calcium hydroxide?
Answers
Answer:
15.2 grams of calcium chloride are produced and HCl is the limiting reactant.
Explanation:
Hello there!
In this case, according to the described scenario, it is possible to realize that the reaction between hydrochloric acid and calcium hydroxide is:
[tex]2HCl+Ca(OH)_2\rightarrow CaCl_2+2H_2O[/tex]
Whereas there is a 2:1 mole ratio of the acid to the base. In such a way, with the given masses, we can compute how much calcium chloride product is produced due to the chemical reaction via stoichiometry:
[tex]m_{CaCl_2}^{by HCl}=10.0gHCl*\frac{1molHCl}{36.46gHCl}*\frac{1molCaCl_2}{2molHCl} *\frac{110.98gCaCl_2}{1molCaCl_2} =15.2gCaCl_2\\\\m_{CaCl_2}^{by Ca(OH)_2}=10.5gHCl*\frac{1molCa(OH)_2}{74.09gCa(OH)_2}*\frac{1molCaCl_2}{1molCa(OH)_2} *\frac{110.98gCaCl_2}{1molCaCl_2} =15.7gCaCl_2[/tex]
Whereas we infer that the correct amount is 15.2 g since HCl is the limiting reactant as it produces the fewest grams of the desired product. Consequently, the calcium hydroxide is the excess reactant here.
Regards!
True or False?
Weak bases dissociate
completely into (OH)- and
metal cations.
Answers
Answer:
False
Explanation:
When weak bases dissociate, an equilibrium is established rather than dissociating 100%. So OH- and metal ions are partially ionized.
HELP ASAP PLEASE!!! :)
Answers
Answer:
Alkane
Explanation:
Alkenes have CH in their condensed formulas and alkynes have C in their condensed formulas. There are only CH3 and CH2 so it's an alkane.
The trait that shows up in the first generation.
Recessive
Dominant
Ok
Answers
Answer:
Dominant
Explanation:
hope this help
how do you think a device could change the sound that we hear? Make sure you use vocabulary such as frequency, energy and amplitude
Answers
Answer:
good luck tho
Explanation:
5. How many grams of Br is needed to make 1000.g of a 2.0ppm solution?
Answers
Answer:
2.0 × 10⁻³ g
Explanation:
Step 1: Given data
Mass of solution: 1000. g (1.000 kg)Concentration of Br₂: 2.0 ppmStep 2: Calculate the mass of Br₂ required to prepare the solution
The concentration of Br₂ is 2.0 ppm, that is, there are 2.0 mg of Br₂ per kilogram of solution. The mass of Br₂ required to prepare 1.000 kg of solution is:
1.000 kg Solution × 2.0 mg Br₂/1 kg Solution = 2.0 mg
Step 3: Convert the mass to grams
We will use the conversion factor 1 g = 1000 mg.
2.0 mg × 1 g/1000 mg = 2.0 × 10⁻³ g
NEED HELP FOR THIS ONE
Answers
Answer:
C₆H₁₂O₆ + 6 O₂ = 6 CO₂ + 6 H₂O
2 KO₂ + H₂O = 2 KOH + 1.5 O₂
Explanation:
Let's consider the following unbalanced equation.
C₆H₁₂O₆ + O₂ = CO₂ + H₂O
We will start balancing H atoms (higher atomicity) by multiplying H₂O by 6.
C₆H₁₂O₆ + O₂ = CO₂ + 6 H₂O
Then, we will balance C atoms by multiplying CO₂ by 6.
C₆H₁₂O₆ + O₂ = 6 CO₂ + 6 H₂O
Finally, to get the balanced equation, we will multiply O₂ by 6.
C₆H₁₂O₆ + 6 O₂ = 6 CO₂ + 6 H₂O
---
Let's consider the following unbalanced equation.
KO₂ + H₂O = KOH + O₂
We will multiply KO₂ and KOH by 2 to balance K and H atoms.
2 KO₂ + H₂O = 2 KOH + O₂
Finally, to get the balanced equation, we will multiply O₂ by 1.5.
2 KO₂ + H₂O = 2 KOH + 1.5 O₂
When NH3(g) reacts with O2(g) to form N2O(g) and H2O(l), 342 kJ of energy are evolved for each mole of NH3(g) that reacts. Write a balanced thermochemical equation for the reaction with an energy term in kJ as part of the equation.
Answers
Answer: [tex]2NH_3(g)+2O_2(g)\rightarrow N_2O(g)+3H_2O(l)+684kJ[/tex]
Explanation:
The skeletal thermochemical equation for the reaction is:
[tex]NH_3(g)+O_2(g)\rightarrow N_2O(g)+H_2O(l)+342kJ[/tex]
The balanced thermochemical equation for the reaction is:
[tex]2NH_3(g)+2O_2(g)\rightarrow N_2O(g)+3H_2O(l)+684kJ[/tex]
When 1 mole of [tex]NH_3[/tex] reacts with oxygen , heat released = 342 kJ
Thus when 2 moles of [tex]NH_3[/tex] reacts with oxygen , heat released = [tex]\frac{2}{1}\times 342 kJ=684kJ[/tex]
Use the following Balanced Equation to complete the question: 2 Al + 6 HBr → 2 AlBr3 + 3 H2
If you have 10 moles of Al how many moles of H2 can be produced?
*Will give Brainly!*
Answers
A student dissolves 15.0 g of ammonium chloride(NH4Cl) in 250. 0 g of water in a well-insulated open cup. She then observes the temperature of the water fall from 20.0 oC to 16.0 oC over the course of minutes. Use this data, and any information you need from the ALEKS Data resource, to answer the questions below about this reaction:
NH4Cl(s) rightarrow NH4+(aq) + Cl-(aq)
You can make any reasonable assumptions about the physical properties of the solution. Note for advanced students: it's possible the student did not do the experiment carefully, and the values you calculate may not be the same as the known and published values for this reaction.
1. Is this reaction exothermic, endothermic, or neither?
2. If you said the reaction was exothermic or endothermic, calculate the amount of heat that was released or absorbed by the reaction in this case.
3. Calculate the reaction enthalpy deltaHrxn per mole of NH4CI.
Answers
Answer:
1) Endothermic.
2) [tex]Q_{rxn}=4435.04J[/tex]
3) [tex]\Delta _rH=15.8kJ/mol[/tex]
Explanation:
Hello there!
1) In this case, for these calorimetry problems, we can realize that since the temperature decreases the reaction is endothermic because it is absorbing heat from the solution, that is why the temperature goes from 22.00 °C to 16.0°C.
2) Now, for the total heat released by the reaction, we first need to assume that all of it is released by the solution since it is possible to assume that the calorimeter is perfectly isolated. In such a way, it is also valid to assume that the specific heat of the solution is 4.184 J/(g°C) as it is mostly water, therefore, the heat released by the reaction is:
[tex]Q_{rxn}=-(15.0g+250.0g)*4.184\frac{J}{g\°C}(16.0-20.0)\°C\\\\ Q_{rxn}=4435.04J[/tex]
3) Finally, since the enthalpy of reaction is calculated by dividing the heat released by the reaction over the moles of the solute, in this case NH4Cl, we proceed as follows:
[tex]\Delta _rH=\frac{ Q_{rxn}}{n}\\\\\Delta _rH= \frac{ 4435.04J}{15.0g*\frac{1mol}{53.49g} } *\frac{1kJ}{1000J} \\\\\Delta _rH=15.8kJ/mol[/tex]
Best regards!
Best regards!
Walking up a flight of stairs and noticing that it gets warmer as you climb
higher is an example of *
5 points
Conduction
Convection
Radiation
Brain damage
Answers
A 72.0 g sample of an organic solid is dissolved in 180mL of water. The solid is extracted using one 60 mL extraction in the first extraction of an organic solvent which has a partition (distribution) coefficient with water of 10. The first extraction removed 55.4 g of solid from water. What are the numbers that need to go in box A and B to calculate the volume of solvent (y) that would be necessary to remove an additional 7.0g from the remaining sample dissolved in water. You DON'T have to complete the calculation to solve for y.
Answers
Answer:
[tex]V_{7.0}\approx 235ml[/tex]
Explanation:
From the question we are told that
mass of sample [tex]M=72.0 grams[/tex]
volume of water [tex]V=180 mL[/tex]
volume for extraction [tex]V'=60mL[/tex]
partition (distribution) coefficient water [tex]d=10[/tex]
initial extraction removal [tex]x=55.4g[/tex]
Generally the equation for the weight of sample [tex]x_n[/tex] is mathematically given by
[tex]x_n=x*(\frac{DV}{DV+V'})^n[/tex]
[tex]x_n=55.4(\frac{10*180}{10*180+60})^1[/tex]
[tex]x_n=53.613g[/tex]
Generally the weight extracted [tex]x_e[/tex] is therefore
[tex]w_e=x-x_n[/tex]
[tex]w_e=55.4-53613[/tex]
[tex]w_e=1.787[/tex]
[tex]w_e=1.787[/tex] is extracted with 60ml solvent .
Therefore volume of solvent (y) that would be necessary to remove an additional 7.0g
[tex]V_{7.0}=\frac{60}{1.767}*7[/tex]
[tex]V_{7.0}=235.030ml[/tex]
[tex]V_{7.0}\approx 235ml[/tex]
8. How much heat will be released when
18.6 g of hydrogen reacts with excess O2
according to the following equation?
Answers
Answer:
15 is it
Explanation:
How did the industrial Revolution impact the population of peppered moths in Britain?
The Industrial Revolution caused the proportions of each color morph in the population to become equal.
The light-colored moths became more common
The dark-colored moths became more common
The Industrial Revolution caused the proportions of each color morph in the population to become unequal
Answers
Answer:
due to the pollution the light months tended to stand out against the the wood that was dark due to the smoke the darker months population grew due to the fact that they were more harder to see for the predators
Answer:
The dark colored months became more common
Explanation:
Thats the answer !
How many moles of NaOH are contained in 56.0 mL of a 2.40 M solution of 1 point
NaOH in water? (**Use only numerical answers with 3 significant figures.
The units are given in the question.)
Your answer
Answers
Answer:
1.34 mol
Explanation:
Molarity, which is the molar concentration of a solution, can be calculated by dividing the number of moles (n) by the volume (V).
That is;
Molarity (M) = n/V
According to the information provided in this question;
M = 2.40M
V = 56.0 mL = 56/1000 = 0.056 L
Since molarity = n/V
number of moles = M × V
n = 0.056 × 24
n = 1.34 mol
A solution is made by dissolving 62.42 g of ammonium sulfate in enough
water to make 50.0 mL of solution. What is the molarity of this solution?
(**Use only numerical answers with 3 significant figures. The units are given
in the question.)
Answers
Answer:
9.46 M
Explanation:
Molarity is a measure of the molar concentration of a solution. It can be calculated by the following formula
Molarity = number of moles/volume
Using moles = mass/molar mass
Molar Mass of Ammonium sulfate (NH₄)₂SO₄ =
{14 + 1(4)}2 + 32 + 16(4)
= {14 + 4}2 + 32 + 64
= 18(2) + 96
= 36 + 96
= 132g/mol
mole = mass/molar mass
mole = 62.42 ÷ 132
mole = 0.473mol
- Molarity = mole ÷ volume
Volume = 50.0 mL = 50/1000 = 0.05 L
Molarity = 0.473 ÷ 0.05
Molarity = 9.46 M
The precision of a method is being established, and the
following
data are obtained 22.23, 22.18 22.25, 22.09
and 22.15%, is 22.09% a valid measurement?
Answers
Answer:
No, 22.09% is not a valid measurement
Explanation:
Precision has to do with how close a given set of measured values are to each other. It is quite different from accuracy. Accuracy refers to how close a given set of values is to the true value. A given set of values may be precise but not accurate and vice versa.
If we look at the values obtained; 22.09%, 22.15%, 22.18%, 22.23%, 22.25%, the value 22.09% is too far off the other values. This implies that it does not represent a valid measurement since it is not close to all the other values obtained.
The reason for using 1-propanol as the solvent of choice for recrystallization is that triphenylphosphine oxide is more soluble in 1-propanol than the alkene product because triphenylphosphine oxide can use its oxygen to hydrogen-bond to 1-propanol, whereas the alkene has no hydrogen-bonding capability. Triphenylphosphine oxide, therefore, is removed based on its polarity and H-bonding ability.
a. True
b. False
Answers
Answer:
True
Explanation:
Hydrogen bonding is a bond that exists between hydrogen and a highly electronegative element such as oxygen, nitrogen, fluorine etc.
The greater solubility of the triphenylphosphine oxide owes to the hydrogen bonded interaction between it and the 1-propanol.
The alkene lacks such hydrogen bonded interaction because it does not have a highly electronegative atom in its structure.
Hence, triphenylphosphine oxide is removed based on its polarity and hydrogen bonding ability.
You have a bag of chips at a constant pressure of 1 Atm with a volume of .5 L and a temperature of 10C. The bag is left under the sun for a couple of hours at a temperature of 35 C, what will its new volume be?
Answers
Answer:
0.54 L
Explanation:
Given that,
Initial volume, V₁ = 0.5 L
Initial temperature, T₁ = 10°C = 283 K
Final temperature, T₂ = 35 C = 308 K
We need to find the final volume. The relation between the volume and temperature is given by :
[tex]\dfrac{V_1}{T_1}=\dfrac{V_2}{T_2}\\\\V_2=\dfrac{V_1T_2}{T_1}\\\\V_2=\dfrac{0.5\times 308 }{283}\\\\V_2=0.54\ L[/tex]
So, the new volume is 0.54 L.
Using the rules that we developed in this chapter (ARIO), we might have expected these two compounds to have the same pKa. Nevertheless, they are different. Salicylic acid is apparently more acidic than its constitutional isomer. Can you offer an explanation for this observation
Answers
Answer:
The correct answer is
- after deprotonation carboxylic acid stabilizes by binding -OH group with hydrogen bonding in salicylic acid and while it's not possible with its constitutional isomer (para-hydroxy benzoic acid).
The more electronegative atoms are replaced by the H atom of the carboxylic group and form more stabilize carboxylic acid which not takes place in para-hydroxy benzoic acid.
A student dissolves 10.3 g of potassium chloride (KCI) in 200. g of water in a well-insulated open cup. She then observes the temperature of the water fall from 22.0 °C to 19.0 °C over the course of 6.8 minutes.
KCI(8) → K+ (aq) + Cl- (aq)
You can make any reasonable assumptions about the physical properties of the solution. Be sure answers you calculate using measured data are rounded to the correct number of significant digits.
Required:
Is this reaction exothermic, endothermic, or neither?
Answers
Answer:
Endothermic.
Explanation:
Hello there!
In this case, it is possible to answer to the requested question "Is this reaction exothermic, endothermic, or neither?" by looking at the temperature change; thus, since the temperature is diminished from 22.0 °C to 19.0 °C, it is possible to realize that the dissociation reaction:
KCI(8) --> K+ (aq) + Cl- (aq)
Is endothermic as it absorbs heat and therefore the solution gets cooled down. Now for any calculation regarding the heat of reaction, it'd be necessary to assume that the solution has a specific heat equal to the water as the former is mostly composed by the latter and the amount of KCl does not modify the solution significantly.
Best regards!
What will be the pH of a buffer solution containing an acid of pKa7.5, with an acid concentration exactly one fourth of that of the conjugate base
Answers
Answer: pH of buffer solution is 8.1
Explanation:
The formula for the Henderson–Hasselbalch equation is:
[tex]pH=pK_a+\log\frac{[A^-]}{[HA]}[/tex]
[tex]pH[/tex] is the concentration of [tex][H^+][/tex]
[tex]pK_a[/tex] is the acid dissociation constant,
[tex]A^-[/tex] and [tex]HA[/tex] are concentrations of the conjugate base and starting acid.
Putting in the values we get:
[tex]pH=7.5+\log\frac{x}{\frac{x}{4}}[/tex]
[tex]pH=8.1[/tex]
Thus pH of buffer solution is 8.1
