Given :
A 75.0 mL sample of water is heated to its boiling point.
To Find :
The heat (in kJ ) is required to vaporize it .
Solution :
Heat of vaporization of water , [tex]\Delta H_{vap}=40.65\ kJ/mol[/tex].
Molar mass of [tex]H_2O[/tex] , [tex]M=18\ g/mol[/tex] .
Density of water , [tex]\rho=1\ g/ml[/tex] .
Mass of 75 ml of water sample , [tex]m=75\ g[/tex] .
Moles of 75 g water = [tex]\dfrac{75}{18}=4.17\ mol[/tex] .
Now , heat required to vaporize 4.17 mol of water :
[tex]H=4.17\times 40.65\ kJ\\\\H=169.51\ kJ[/tex]
Therefore , heat required to boil 75 ml sample of water is 169.51 kJ.
Hence , this is the required solution .
Convert 2.350 km/hour to cm/sec HELP NOW PLEASE!!!! I NEED THE WORK
Answer:
1km/h =27.778cm/s
therefore
if 1km/h=27.778cm/s
2.350km/h=?
cross multiple
2.350km/h X27.778cm/s /1km/h
=65.2783cm/s
The oxides of nitrogen are very important ingredients in determining urban air pollution. Name each of the following compounds.(a) N2O(b) NO(c) NO2(d) N2O5(e) N2O4
Answer:
(a) N₂O - Dinitrogen monoxide or Dinitrogen (I) oxide
(b) NO - Nitrogen monoxide or Nitrogen (II) oxide
(c) NO₂ - Nitrogen dioxide or Nitrogen (IV) oxide
(d) N₂O₅ - Dinitrogen pentoxide
(e) N₂O₄ - Dinitrogen tetraoxide.
Explanation:
To name each of the compounds,
(a) N2O; It is properly written as N₂O. N₂O is a colorless, sweet tasting gas also known as "laughing gas".
N₂O - Dinitrogen monoxide OR Dinitrogen (I) oxide.
(b) NO; NO is a colorless gas.
NO - Nitrogen monoxide OR Nitrogen (II) oxide.
(c) NO2; It is properly written as NO₂
NO₂ is a reddish-brown gas.
NO₂ - Nitrogen dioxide or Nitrogen (IV) oxide.
(d) N2O5; It is properly written as N₂O₅
N₂O₅ is a white solid.
N₂O₅ - Dinitrogen pentoxide.
(e) N2O4; It is properly written as N₂O₄;
N₂O₄ is a red-brown liquid with an unpleasant smell.
N₂O₄ - Dinitrogen tetraoxide.
Monobromination of toluene gives a mixture of three bromotoluene products. Draw and name them.
Answer:
o-bromotoluene, m-bromotoluene and p-bromotoluene.
Explanation:
Hello,
In this case, on the attached picture you will find the reaction which yields o-bromotoluene as the first product, m-bromotoluene as the second product and p-bromotoluene as the last one since the substitution could be done at the second (ortho), third (meta) or fourth (para) carbons on the toluene.
Regards.
Carry out the following. Please help!
A. 10^4 X 10^5
B. 10^4 X 10^-5
C. 10^4 / 10^5
Answer:
A. 10^9
B. 10^-1
C. 10^-1
For the following, identify the most likely value for x.a. BHx b. CHx c. NHx d. CH2Clx
Given :
a. [tex]BH_x[/tex] b. [tex]CH_x[/tex] c. [tex]NH_x[/tex] d. [tex]CH_2Cl_x[/tex] .
To Find :
Find the most likely vale of x for each one .
Solution :
a . [tex]BH_x[/tex]
Because boron have valency of 3 .
So , x = 3 .
b . [tex]CH_x[/tex]
Valency of carbon is 4 .
x = 4 .
c . [tex]NH_x[/tex]
Valency of nitrogen is 3 .
Therefore , x = 3 .
d . [tex]CH_2Cl_x[/tex]
Now ,we know valency of carbon is 4 and hydrogen is 1 .
Also , two hydrogen are already there .
So , only 2 electrons left to share .
Since , chlorine have valency of 1 .
Therefore , only 2 electrons of chlorine can connect .
x = 2 .
Hence , this is the required solution .
How many different elements occur naturally?
Answer:
94 are naturally made on earth
Explanation:
Answer:
94 or 98, i think.
Explanation:
Yesinia read that certain perfume ingredients, called esters, would agitate bees. Because perfume formulas are secret, she decided to determine whether the unknown Ester X was present in four different perfumes by observing the bees’ behavior. She placed a saucer containing 10 mL of the first perfume 3 meters from the beehive. She recorded the time required for the bees to emerge and made observations on their behavior. After a 30-minute recover period, she tested the second, third and four perfumes. All experiments were conducted on the same day when the weather conditions were similar, that is, air temperature and wind. What was the hypothesis? What would be the control group? What is the experimental group? What was deliberately changed? What responded to the change?
Answer:
Hypothesis: IF the perfumes contained Ester "X", THEN the bees would be agitated
Control group: The control group would be the group of bees that did not receive any perfume treatment
Experimental group: Bees that were exposed to the different perfumes
Independent variable: The type of perfumes
Dependent variable: the behavior of the bees
Explanation:
An hypothesis is a testable explanation or suggested solution to a problem that is subject to testing (for proving or disproving) via experimentation. The hypothesis of this experiment will be: IF the perfumes contained Ester "X", THEN the bees would be agitated
The control group of an experiment is the group that does not receive the experimental treatment or the group whose independent variable is not changed. In this case, there is no stated control group but control group of this particular experiment could be the BEES THAT WERE NOT EXPOSED TO ANY PERFUME.
The experimental group, as opposed to the control group, is the group that receives experimental treatment. In this case, it is the group of bees that were exposed to the different types of perfumes.
In an experiment, the variable that is deliberately changed by the experimenter is called the independent variable. The independent variable in this question is the TYPE OF PERFUME given to the bees.
The variable that responds to the changes made to the independent variable is called the dependent variable. The dependent variable, which is the measured variable, is THE BEHAVIOR OF THE BEES.
Select the correct answer.
Which phrase best describes heat?
O A. the energy that an object has as a result of its temperature
OB. the average translational kinetic energy of the particles in an object
ОС. the energy transferred between objects at different temperatures
OD
the total amount of energy possessed by the particles in an object
Answer:
C is the answer hope I helped you have a good day by
Hydrogen reacts with nitrogen monoxide to form dinitrogen monoxide (aughing gas) according to the equation: H2 (9) + 2 NOg) N20() + H20G) Based on the following data: H2 (M) NO (M) Rate (M*s) Trial 1 0.30 0.35 2.835 x 10-3 Trial 2 0.60 0.35 1.134 x 10-2 Trial 3 0.60 0.70 2.268 x 10-2 a. What is the order with respect to H2? b. What is the order with respect to NO? c. What is the rate equation for this reaction? d. Calculate the rate constant for the reaction.
Explanation:
H2 (9) + 2 NOg) N20() + H20G)
H2 (M) NO (M) Rate (M*s)
Trial 1 0.30 0.35 2.835 x 10-3
Trial 2 0.60 0.35 1.134 x 10-2
Trial 3 0.60 0.70 2.268 x 10-2
a. What is the order with respect to H2?
Comparing trials 1 and 2,the concentration of H is doubled and that leads to an increase in the rate of the reaction by a factor of 4. This means the order with respect to H is 2.
b. What is the order with respect to NO?
Comparing trials 2 and 3, the concentration of NO is doubled and that leads to an increase in the rate of the reaction by a factor of 2. This means the order with respect to NO is 1.
c. What is the rate equation for this reaction?
rate = k [H]²[NO]
d. Calculate the rate constant for the reaction.
Taking trial 1;
rate = k [H]²[NO]
2.835 x 10-3 = k (0.30)² (0.35)
k = 90 x 10-3 = 0.09 L2 mol-2 s-1
If you know the force applied to an object and measure its acceleration, which equation would you use to calculate the object’s mass? m = Fa m = a F m = a/F m = F/a
Answer: m=F/a
Explanation:
Answer:
d
Explanation:
Enter a balanced equation for the reaction between aqueous lead (II) nitrite and aqueous lithium chloride to form solid lead (II) chloride and aqueous lithium nitrite.
Answer:
Pb(NO₂)₂(aq) + 2 LiCl(aq) ⇒ PbCl₂(s) + 2 LiNO₂(aq)
Explanation:
Let's consider the reaction between aqueous lead (II) nitrite and aqueous lithium chloride to form solid lead (II) chloride and aqueous lithium nitrite.
Pb(NO₂)₂(aq) + LiCl(aq) ⇒ PbCl₂(s) + LiNO₂(aq)
This is a double displacement reaction. We will start balancing Cl by multiplying LiCl by 2.
Pb(NO₂)₂(aq) + 2 LiCl(aq) ⇒ PbCl₂(s) + LiNO₂(aq)
Now, we have to balance Li by multiplying LiNO₂ by 2.
Pb(NO₂)₂(aq) + 2 LiCl(aq) ⇒ PbCl₂(s) + 2 LiNO₂(aq)
The equation is now balanced.
The balanced chemical reaction equation required is; Pb(NO2)2(aq) + 2 LiCl(aq) -----> PbCl2(s) + 2LiNO2(aq)
In order to write a balanced chemical reaction equation, we must write down the symbols of the compounds involved as follows;
lead (II) nitrite - Pb(NO2)2
lithium chloride - LiCl
lead (II) chloride - PbCl2
lithium nitrite - LiNO2
Recall that the principle of writing a balanced chemical reaction equation is that the number of atoms of each element on both sides of the reaction equation must be the same. The required balanced chemical reaction equation is;
Pb(NO2)2(aq) + 2 LiCl(aq) -----> PbCl2(s) + 2LiNO2(aq)
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Archimedes tells us the lifting power of a balloon (how much mass it can lift) is equal to the difference between the mass of the balloon and the mass of the air it displaces. That is, if the balloon occupies the same volume as 10 kg of air, but the balloon only weighs 2 kg, then the balloon can lift 8 kg. gas densityH2 0.09 kg/m3He 0.18 kg/m3Air 1.23 kg/m3 Airships have sometimes been filled with hydrogen (H), but hydrogen is very flammable, and after the Hindenburg caught fire and crashed in 1937 with serious loss of life airships have nearly always been filled with helium (He) instead. Suppose a new airship Star of Balogna will have the shape of a cylinder 40. m long, with a radius of 4.0 m, and will weigh 750. kg without any gas inside it. Suppose also the average passenger weighs 80 kg. Calculate how many passengers the Balogna could carry if it were filled with hydrogen, and also if it were filled with helium. Passengers with Hz: 29Passengers with He: 26
Answer:
the Balogna could carry 19 passengers if filled with Hydrogen.
the Balogna could carry 17 passengers if filled with Helium.
Explanation:
Given that:
the radius of the cylinder r = 4.0 cm
the height h = 40 m
the volume of the cylinder will be:
[tex]V = \pi r^2 h[/tex]
V = π (4.0 m)² (40)
V = 2010.62 m³.
where the density of the air = 1.23 kg/m³
the mass of the displaced air = Volume V ×density of the air
= 2010.62 m³ × 1.23 kg/m³
= 2473.0626 kg
To calculate how many passengers the Balogna could carry if it were filled with hydrogen, we have the following:
We are given the density of H₂ to be = 0.090 kg/m³
Therefore, the mass of Helium in the balloon = Volume V × density of the hydrogen
= 2010.62 m³ × 0.090 kg/m³
= 180.9558 kg
The total mass of the balloon = mass of H₂ + mass of empty balloon.
The total mass of the balloon = (180.9558+ 750) kg
= 930.9558 kg
Now, the Mass difference = mass of the air displaced -total mass of the balloon.
the Mass difference = (2473.0626 - 930.9558 ) kg
the Mass difference = 1542.1068 kg
∴
number of persons = mass difference/ mass of passenger
the number of persons = 1542.1068 kg /80 (kg/person)
the number of persons = 19.27 persons
the number of passengers [tex]\simeq[/tex] 19 passengers.
To calculate how many passengers the Balogna could carry if it were filled with helium, we have the following:
We are given the density of Helium to be = 0.18 kg/m³
Therefore, the mass of Helium in the balloon = Volume V × density of the hydrogen
= 2010.62 m³ × 0.18 kg/m³
= 361.9116 kg
The total mass of the balloon = mass of Helium + mass of empty balloon.
The total mass of the balloon = (361.9116 + 750) kg
= 1111.9116 kg
Now, the Mass difference = mass of the air displaced -total mass of the balloon.
the Mass difference = (2473.0626 - 1111.9116 ) kg
the Mass difference = 1361.151 kg
∴
number of persons = mass difference/ mass of passenger
the number of persons = 1361.151 kg /80 (kg/person)
the number of persons = 17.01 persons
the number of passengers [tex]\simeq[/tex] 17 passengers.
Rank the following bonds in order of decreasing bond length, based on periodic trends, starting with the longest bond at the top of the list.H-S H-I H-Se H-BI. H-I II. H-SeIII. H-BrIV. H-S
Answer:
H-BI,H-Se,H-S,H-I,H-Br
Explanation:
One thing that must be kept in mind is that atomic size increases down the group and decreases across the period. The bond lengths of species are influenced by the relative sizes of atoms or ions present in the bond.
The bonds in the answer have been arranged on basis of their decreasing atomic size because the greater the atomic size of the atoms, the greater the bond length and vice versa.
You found several studies related to the service provided by the company. Which data will you use to make an informed decision? Check all that apply.
data from a celebrity magazine
data verified by other studies
data provided by an ice cream manufacturer
data gathered once to show the reliability of the company
data from a report put out by a government agency
Answer: it’s b,c and e ,your welcome :) (just took the test on edge)
Answer:
B. data verified by other studies
C. data provided by an ice cream manufacturer
E. data from a report put out by a government agency
Explanation:
I need help ASAP!! Plzz
Answer:
0.1
tenth
hundredth (0.01)
1.05 (can be anywhere from 1.00 to 1.10)
11.42 (can be anywhere from 11.40 to 11.50)
yes, it falls within reasonable doubt
Eric's father asked an engineer to survey the field behind their house. He wanted to plant some apple and pear trees there. According to the survey, the field is 38 meters (m) long and 17 meters (m) wide. What is the perimeter of the field in centimeters?
Answer:
P=110 m
Explanation:
Length of the field is 38 m
Breadth of the field is 17 m
We need to find the perimeter of this field. It is in the form of a rectangle. The perimeter of a rectangle is given by :
P=2(l+b)
P=2(38+17)
P=110 m
So, the perimeter of this field is 110 m.
Which statement is false? a) When reactants become products, they do so through an intermediate transition state. b) At equilibrium, equal amounts of products and reactants are present. c) Most biocatalysts are proteins. d) AG is a function of Keq
Answer:
b) At equilibrium, equal amounts of products and reactants are present.
Explanation:
At equilibrium , the ratio of product of concentration of products and product of concentration of reactants is constant .
A + B ⇄ C + D
[C] [ D] / [ A ] [ B ] = Constant
So, the statement ( b ) is false .
All other statements are true .
The [H+] of a solution can be determined from the pH using the equation: [H+] = 10 - pH ... Where: [H+] = hydrogen ion concentration. Note: Write [H+] as [H+]. Capitalization counts. Use the rules for logarithms and exponents to solve for pH in terms of [H+].
Answer:
pH = -log₁₀ [H⁺]
Explanation:
pH is a value in chemistry used in to measure solution trying to determine each quality, purity, risks for health of some products, etc.
As you write in the question, [H⁺] = 10^(-pH)
Using logarithm law (log (m^(p) = p log(m):
log₁₀ [H⁺] = -pH
And
pH = -log₁₀ [H⁺]Answer:
7 (a neutral solution)
Answer: 10-7= 0.0000001 moles per liter
5.6 (unpolluted rainwater)
Answer: 10-5.6 = 0.0000025 moles per liter
3.7 (first acid rain sample in North America)
Answer: 10-3.7 = 0.00020 moles per liter
The concentration of H+ in the Hubbard Brook sample is 0.00020/0.0000025, which is 80 times higher than the H+ concentration in unpolluted rainwater.
Explanation:
plato
What are the properties of the aluminum in the
can? Check all that apply.
It conducts electricity well.
It is solid
It is brittle.
It does not react easily with water or air.
It is less dense than water.
Answer:
What are the properties of the aluminum in the can? Check all that apply.
*It conducts electricity well.
*It is solid.
It is brittle.
*It does not react easily with water or air.
It is less dense than water.
Explanation:
a b d
The properties of aluminium (Al) includes electrical conductivity, solid and it does not react easily with water. Therefore, option A, B and D are correct.
What is aluminium?Aluminium is a common metal we use day to day. It is an electropositive element and due to its metallic nature, Al shows electrical and thermal conductivity. Unlike other metals Al can withstand brittleness and it is ductile in nature.
Aluminium easily reacts with oxygen and forms an oxide layer on its surface so that, it can resist attack by other chemical such as acid or bases as well as oil and water. Hence water does not easily react with aluminium.
Therefore, we can say that aluminium is a solid which conduct electricity and not easily reacts with water.
To learn more about Al, refer the link below:https://brainly.com/question/23755698
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Classify each substance based on the intermolecular forces present in that substance.A. H2OB. CH4C. CO D. CH3Cl1. Hydrogen bonding, dipole dipole, and dispersion2. Dipole dipole and dispersion only 3. Dispersion only
Answer:
H2O - Hydrogen bonding, dipole dipole, and dispersion
CH4 - Dispersion only
CO - Dipole dipole and dispersion only
CH3Cl - Dipole dipole and dispersion only
Explanation:
Hydrogen bonding can only exist when hydrogen is bonded to a small highly electronegative atom such as oxygen hence hydrogen bonds, dipole interactions and dispersion by are present in water.
CH4 is a nonpolar molecule hence only dispersion forces are present.
CH3Cl and CO both possess dipoles in the molecule hence both dipole interactions and dispersion forces exist in the molecule.
SN1 reactions of the type, Nu- + RL → Nu–R + L-, are favoured:a. when tertiary substrates are used. b. by using a high concentration of the nucleophile. c. when L- is a strong base. d. by use of an aprotic solvent.
A car drives on a road at a constant speed of 50 miles/hour.
The forward force of the car is ________________
the opposing friction and air
resistance forces.
The forward force of the car and the opposing friction and air resistance forces are ____________
( !!
Answer:
It will take the police car 3.5 hours to travel a distance of 175 miles traveling at a rate of 50 miles/hour.
Explanation:
the weight of a sack potato in india is 50kgf. will the weight increase or decrease in bhutan. why
Answer:
Assume that the sack was initially close to the sea level. Its weight will increase even though its mass stays the same.
Explanation:
The weight of an object typically refers to the size of the planet's gravitational attraction (a force) on this object. That's not the same as the mass of the object. The weight of an object at a position depends on the size of the gravitational field there; on the other hand, the mass of the object is supposed to be same regardless of the location- as long as the object stays intact.
Let [tex]g[/tex] denote the strength of the gravitational field at a certain point. If the mass of an object is [tex]m[/tex], its weight at that point will be [tex]m \cdot g[/tex].
Indeed, [tex]g \approx 9.81\; \rm N \cdot kg^{-1}[/tex] on many places of the earth. However, this value is accurate only near the sea level. The equation for universal gravitation is a more general way for finding the strength of the gravitational field at an arbitrary height. Let [tex]G[/tex] denote the constant of universal gravitation, and let [tex]M[/tex] denote the mass of the earth. At a distance [tex]r[/tex] from the center of the earth (where
[tex]\displaystyle g \approx \frac{G \cdot M}{r^2}[/tex].
The elevation of many places in Bhutan are significantly higher than that of many places in India. Therefore, a sack of potato in Bhutan will likely be further away from the center of the earth (larger [tex]r[/tex]) compared to a sack of potato in India.
Note, that in the approximation, the value of [tex]g[/tex] is (approximately, because the earth isn't perfectly spherical) inversely proportional to the distance from the center of the planet. The gravitational field strength
On the other hand, the weight of an object of fixed mass is proportional to the gravitational field strength. Therefore, the same bag of potatoes will have a smaller weight at most places in Bhutan compared to most places in India.
Which atom is most likely to form a metallic bond?
aluminum (Al)
helium (He)
phosphorus (P)
carbon (C)
Answer:
I would say it's A just because it's make no sense for the other answers.
Aluminum atom is most likely to form a metallic bond.
METALLIC BONDS:
Metallic bonds are the kind of bonds that forms between metallic atoms. Electrons are shared between the positive ions called cations. These electrons are called localized electrons. Metallic bonds are responsible for the properties possessed by metals such as conductivity, lustre etc. Since metallic bonds forms between metal atoms, it is most likely to form between aluminum atom.Learn more: https://brainly.com/question/20511339?referrer=searchResults
Choose all the answers that apply.
Which of the following statements are true?
Ethical scientists make unbiased conclusions.
A dishonest scientst has a lot of integrity.
Confirmation bias is the most common type of bias in science.
Science is based on opinion and subjective evidence.
Bias can be ruled out when similar results are obtained from repeated experiments.
Explanation:
A dishonest scientst has a lot of integrity.
Confirmation bias is the most common type of bias in science.
Answer: ethical scientists make unbiased conclusions, science is based on opinion and subjective evidence, and bias can be ruled out if similar results are obtained from repeated experiments.
Explanation: If you’re a dishonest scientist you don’t have integrity and confirmation bias isn’t the most common type of bias in science
Which of the following pairs exhibit an ion-dipole interaction? a. CH_3OH and Na^+ b. Cl^- and K^+ c. CH_3CH_2CH_2CH_2CH_3 and CH_3CH_2CH_2CH_2COOH d. CH_3CH_2OH and H_2O
Answer:
a. CH_3OH and Na^+
Explanation:
Ion-dipole interaction is the forces of attraction existing between a polar compound and an ion. This particular type of ion-dipole attraction occurs between an electrostatic attraction of an ion and a dipole molecule.
From the given example, CH3OH is a polar compound, and Na^+ is an ion. Therefore, that is the only pair that exhibit the characteristics of an ion-dipole interaction.
Calculate the solubility of PbCO3 in water at 25 degree C.
Answer:
2.7 × 10⁻⁷ M
Explanation:
Step 1: Write the reaction for the solution of PbCO₃
PbCO₃(s) ⇄ Pb²⁺(aq) + CO₃²⁻(aq)
Step 2: Make an ICE chart
To relate the solubility of PbCO₃ (S) with its solubility product constant (Ksp) we will make an ICE chart.
PbCO₃(s) ⇄ Pb²⁺(aq) + CO₃²⁻(aq)
I 0 0
C +S +S
E S S
The solubility product constant is:
Ksp = 7.4 × 10⁻¹⁴ = [Pb²⁺] × [CO₃²⁻] = S²
S = √7.4 × 10⁻¹⁴ = 2.7 × 10⁻⁷ M
We can see each other in the classroom right now because we
a.reflect visible light
b. absorb visible light
c.reflect infrared light
d.absorb radio waves.
Answer:
The answer is A
Reflect visible light
The solubility of oxygen in water A. allows for a greater concentration of O2 in water than in air. B. is responsible for thermoclines. C. is greater in cool liquid water than in warm liquid water. D. isn't significantly dependent on temperature
The ans should be C. ( if i'm not wrong )
This is because the solubility of oxygen increases when temperature in the water is cooler. Cold water can hold more dissolved oxygen than warm water, thus having a higher concentration of oxygen.
Answer:
C. is greater in cool liquid water than in warm liquid water.
Explanation:
H
Н
НЕС-С-ОН
1
Hн
Look carefully at the structural drawing for ethanol above.
How many carbons (C) does an ethanol molecule have?
2
3
6
1
HELPPPPPPPP
Answer:c
Explanation: it's easy