Answer:
11
∘
C
Explanation:
As far as solving this problem goes, it is very important that you do not forget to account for the phase change underwent by the solid water at
0
∘
C
to liquid at
0
∘
C
.
The heat needed to melt the solid at its melting point will come from the warmer water sample. This means that you have
q
1
+
q
2
=
−
q
3
(
1
)
, where
q
1
- the heat absorbed by the solid at
0
∘
C
q
2
- the heat absorbed by the liquid at
0
∘
C
q
3
- the heat lost by the warmer water sample
The two equations that you will use are
q
=
m
⋅
c
⋅
Δ
T
, where
q
- heat absorbed/lost
m
- the mass of the sample
c
- the specific heat of water, equal to
4.18
J
g
∘
C
Δ
T
- the change in temperature, defined as final temperature minus initial temperature
and
q
=
n
⋅
Δ
H
fus
, where
q
- heat absorbed
n
- the number of moles of water
Δ
H
fus
- the molar heat of fusion of water, equal to
6.01 kJ/mol
Use water's molar mass to find how many moles of water you have in the
100.0-g
sample
100.0
g
⋅
1 mole H
2
O
18.015
g
=
5.551 moles H
2
O
So, how much heat is needed to allow the sample to go from solid at
0
∘
C
to liquid at
0
∘
C
?
q
1
=
5.551
moles
⋅
6.01
kJ
mole
=
33.36 kJ
This means that equation
(
1
)
becomes
33.36 kJ
+
q
2
=
−
q
3
The minus sign for
q
3
is used because heat lost carries a negative sign.
So, if
T
f
is the final temperature of the water, you can say that
33.36 kJ
+
m
sample
⋅
c
⋅
Δ
T
sample
=
−
m
water
⋅
c
⋅
Δ
T
water
More specifically, you have
33.36 kJ
+
100.0
g
⋅
4.18
J
g
∘
C
⋅
(
T
f
−
0
)
∘
C
=
−
650
g
⋅
4.18
J
g
∘
C
⋅
(
T
f
−
25
)
∘
C
33.36 kJ
+
418 J
⋅
(
T
f
−
0
)
=
−
2717 J
⋅
(
T
f
−
25
)
Convert the joules to kilojoules to get
33.36
kJ
+
0.418
kJ
⋅
T
f
=
−
2.717
kJ
⋅
(
T
f
−
25
)
This is equivalent to
0.418
⋅
T
f
+
2.717
⋅
T
f
=
67.925
−
33.36
T
f
=
34.565
0.418
+
2.717
=
11.026
∘
C
Rounded to two sig figs, the number of sig figs you have for the mass of warmer water, the answer will be
T
f
=
11
∘
C
Explanation:
g Given that ammonia (NH3) acts as a weak base in water with a Kb of 1.8 x 10-5 at 298.0 K, calculate the pH at 298.0 K of a solution prepared by mixing 100.0 mL of a 0.050 M aqueous solution of ammonia with 20.0 mL of a 1.00 M aqueous solution of nitric acid. The final volume of the solution is 120.0 mL.
Answer:
pH = 0.90
Explanation:
The NH3 reacts with nitric acid, HNO3 as follows:
NH3 + HNO3 → NH₄⁺ + NO₃⁻
Where 1 mole of NH3 reacts per mole of HNO3.
The moles added of each reactant are:
Moles NH3:
100mL = 0.100L * (0.050mol / L) = 0.0050 moles NH3
Moles HNO3:
20mL = 0.0200L * (1.00mol / L) = 0.0200 moles HNO3
That means HNO3 is the excess reactant and, after the reaction, its moles are:
0.0200mol - 0.0050mol = 0.0150 moles HNO3
In a final volume of 120mL = 0.120L, the molar concentration of HNO3 is:
0.0150 moles HNO3 / 0.120L = 0.125M HNO3
As nitric acid is a strong acid, [HNO3] = [H+]
[H+] = 0.125M
pH = -log[H+]
pH = 0.90which is best illustrated by Watson and Crick's ball and stick model of dna
Answer:
Here is your Answer.......
Explanation:
The Watson and Crick's ball-and-stick model of DNA best illustrates the role of creativity in scientific discovery
what is the pH of a 2.58 x 10^-6 M solution of an acid?
Answer:
5.59Explanation:
The pH of a solution can be found by using the formula
[tex]pH = - log [ {H}^{+} ][/tex]
From the question we have
[tex]ph = - log(2.58 \times {10}^{ - 6} ) \\ = 5.58838[/tex]
We have the final answer as
5.59Hope this helps you
what is the name of the functional group of pentanoic acid
Answer:
organic acid
Explanation:
Answer:
Hey mate.....
Explanation:
This is ur answer.....
Alkyl carboxylic acid
Valeric acid (pentanoic acid) is a straight-chain alkyl carboxylic acid with a very unpleasant odor. It is found naturally in the perennial flowering plant valerian (Valeriana officinalis), from which it gets its name.
Hope it helps!
Brainliest pls!
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You have made a 2.5 molar solution (2.5 moles per liter) of a particular chemical. If the molecular weight of the chemical is 28 g (28 g/mol), how many kg of the chemical are dissolved in 1 L of this solution
Answer:
Mass of solute in Kg = 0.07 Kg
Explanation:
Given
Molecular weight of the chemical = 28 grams per mole
Solution consists of 2.5 moles of solution
Mass of solute in the solution = 2.5 *28 = 70 grams
Mass of solute in Kg = 70 grams/1000 = 0.07 Kg
Calculate the volume occupied
at s.t.p by 6.89
gas [H = 10, N = 14
Answer:
9.07 L
Explanation:
Calculate the volume occupied at s.t.p by 6.89 g of NH₃ gas [H = 1.0, N = 14.0].
Step 1: Given and required data
Mass of NH₃ (m): 6.89 gMolar mass of NH₃ (M): 17.0 g/molStep 2: Calculate the moles (n) of NH₃
We will use the following epxression.
n = m / M
n = 6.89 g / (17.0 g/mol) = 0.405 mol
Step 3: Calculate the volume occupied by 0.405 moles of NH₃ at STP
At STP, 1 mole of NH₃ occupies 22.4 L (assuming ideal behavior).
0.405 mol × 22.4 L/1 mol = 9.07 L
The carbon-oxygen double bond, or carbonyl, is a key feature of many organic molecules. Two resonance structures can be used to illustrate the properties of the carbonyl structure as provided. In analyzing the minor resonance structure, what can we conclude about the Lewis acid properties of the carbonyl
The question is incomplete, the complete question is shown in the image attached to this answer
Answer:
B
Explanation:
A Lewis acid is specie that has vacant orbitals and is able to accept a lone pair of electrons while a Lewis base is any specie having a lone pair of electrons which can be donated to another chemical specie.
Hence a Lewis acid accepts a lone pair of electrons while a Lewis base donates a lone pair of electrons.
From the resonance structure shown, the carbon atom in the carbonyl compound ought to function as the Lewis acid since it is electrophilic (electron deficient).
Answer: The Carbon atom in the carbonyl will act as a lewis acid and will accept a pair of electrons
Explanation:
In the minor resonance structure for the carbonyl group, we observe a positive formal charge on the carbon atom. Because of its positive formal charge, the carbon atom will act as a Lewis acid and accept a pair of electrons to stabilize that formal charge.
Name the substance which occurs in all the physical states in nature?
Answer: water
For many centuries, it was considered that there were only three states of matter: solid, liquid and gas (the three that are present and stable in our world). And water is the substance that best represents them, because it is the only one that exists naturally in the three states.
Explanation: Matter can exist in one of three main states: solid, liquid, or gas.
Solid matter is composed of tightly packed particles. ...
Liquid matter is made of more loosely packed particles. ...
Gaseous matter is composed of particles packed so loosely that it has neither a defined shape nor a defined volume.
Answer:
Water is the only common substance that is naturally found as a solid, liquid or gas. Solids, liquids and gases are known as states of matter.
Feel free to mark it as brainliest :D
Ignore this part unless you want to understand out of your syllabus:
However, if you take into account the fifth state of matter, Bose-Einstein Condensate, which has been recently discovered, there is no substance as such.
how many moles of potassium+hydroxide+would+react+with+one+mole+of+hydrocloric acid
Answer:
1 mole of potassium hydroxide, KOH
Explanation:
We'll begin by writing the balanced equation for the reaction. This is illustrated below:
KOH + HCl —> KCl + H₂O
Considering the balanced equation above, we can see clearly that 1 mole of potassium hydroxide, KOH reacted with 1 mole of hydrochloric acid, HCl.
Therefore, we can conclude that at every given point, 1 mole of potassium hydroxide, KOH is required to react with 1 mole of hydrochloric acid, HCl.
Which area of chemistry best links the use of titanium and plastics in artificial bone and joint replacements?
A) environmental chemistry
B) materials chemistry
C) agricultural chemistry
D) physical chemistry
Answer:I think it’s material chemistry
Explanation:
Answer:
Material chemistry.
Explanation:
Artificial bone and joint replacements is not environmental, it does not have anything to do with farming or such things, and physical chemistry has to do with chemical reactions which is not going on. This leaves materials chemistry.
A yellow powder and a blue liquid are shaken together in a test tube to produce a clear green mixture that is all liquid.
Which of the following best describes the behavior of the above pair of substances?
Answer:
hkj
Explanation:
Name one major function of the organ systems listed below.
1. Skeletal System
2. Muscular System
3. Digestive System
4. Respiratory System
5. Circulatory System
6. Nervous System
7. Urinary System
Plss help I’ll give u 35 points
The organ system has been defined as the collective working of the organs for performing a specified task. Each organ system has been assigned a major task to be performed.
The function of the following organ systems have been:
Skeletal system: It has been comprised of bones and muscle. The major function of skeletal system has to maintain the body structure, and allow the interaction of muscular system to nervous system.Muscular system: It has been dealing with the voluntary and involuntary muscles. The major function has been the operation of the skeletal system by following the commands from the nervous system.Digestive system: It has been comprised of esophagus, stomach, intestine. The major function has been the breakdown of food and absorption of nutrients.Respiratory system: The respiratory system has been comprised of lungs and trachea. It has a major function of release of harmful gases, as well as oxidation and reduction of the byproducts of glycolysis.Circulatory system: It has been majorly comprises heart. The major function has been purification of blood and transport to different parts of the body.Nervous system: It has been comprised of brain and neurons, the function has been transmission of signals to the stimuli and responsible for conscious and subconscious behavior.Urinary system: The major part has been kidneys and the nephrons. The function has been the filtration of the waste liquid and urination.For more information about organ system, refer to the link:
https://brainly.com/question/12825206
A 15.67 g sample of a hydrate of magnesium carbonate was heated, without decomposing the carbonate, to drive off the water. The mass was reduced to 7.58 g. What is the name of the hydrate
Answer:
The correct answer is MgCO₃.5H₂O.
Explanation:
Based on the given information,
The mass of hydrate of magnesium carbonate given is 15.67 grams, and the mass of anhydrous magnesium carbonate given is 7.58 grams.
Now the mass of water will be,
= 15.67 grams – 7.58 grams
= 8.09 grams
The molecular mass of magnesium carbonate is 84.32 grams, the moles of MgCO₃ can be determined by using the formula,
Number of moles = Mass/Molecular mass
Moles of MgCO₃ = 7.58/84.32
= 0.0898 moles
Similarly, the number of moles of water will be,
Moles of H₂O = 8.099/18.02
= 0.4489 moles
After getting the values, there is a need to choose the smaller value and use it to divide both the values to get the ratio,
MgCO₃ = 0.0898/0.0898 = 1
H₂O = 0.4489/0.0898 = 4.9 or 5
Thus, the molecular formula for the hydrate will be MgCO₃.5H₂O.
If 330 grams of potassium chloride, KCl, is dissolved in enough water to make 2.53 liters of solution, what is the concentration (in molarity) of the solution?
could you theoretically cook methamphetamine? just wonderkng.
what is the colour of litmus in a solution of ammonium hydroxide?
Answer:
Red litmus turns blue
Explanation:
Hope it helps
The base area of a pyramid is 1,225m2.if the pyramid is 11.3m high,what is it's volume
Answer:
Volume = 4614 m³
Explanation:
The volume of a pyramide is given by the following formula:
Volume = 1/3 * base area * heightWe are already given all the required information to calculate the volume by inputting the data:
Volume = 1/3 * 1225 m² * 11.3 mVolume = 4614 m³The pyramid's volume is 4614 cubic meters.
PLS HELP
When 50.0 g of copper was reacted with 300.0 g of silver nitrate solution, 149 g of silver was obtained. What is the percent yield of silver obtained?
Answer:
Percent yield of silver obtained = 78.18% (Approx.)
Explanation:
Given:
Amount of copper = 50 gram
Amount of silver nitrate = 300 gram
Amount of silver = 149 gram
Find:
Percent yield of silver obtained
Computation:
Percentage of Silver in silver nitrate = 108[100/(108+14+48)]
Percentage of Silver in silver nitrate = 108/[100/170]
Percentage of Silver in silver nitrate = 63.53% (Approx.)
Amount of Silver produced = [63.53%][300]
Amount of Silver produced = 190.59 gram
Percent yield of silver obtained = [Amount of silver / Amount of silver produced]100
Percent yield of silver obtained = [149/190.59]100
Percent yield of silver obtained = 78.18% (Approx.)
How many molecular orbitals are present in the valence band of a sodium crystal with a mass of 4.14 g
Answer:
Explanation:
Given that:
The mass of sodium crystal = 4.14 g
As a result, the number of atoms in the sodium crystal is:
[tex]=4.14 \g \times \dfrac{ 1 \ mol}{23.0 \ g }\times \dfrac{6.023 \times 10^{23} \ atoms}{1 \ mol}[/tex]
= 1.084 × 10²³ atoms
In the valence orbital of the sodium atom, there is just one electron.
As a result, the number of molecular orbitals produced by these atoms is= 1.084 × 10²³ molecular orbital
Because valence bands are created from occupied molecular orbitals, the number of valence bands created from the aforementioned molecular orbitals is:
[tex]= \dfrac{ 1.084 \times 10^{23}}{2}[/tex]
= 5.420 × 10²² orbitals.
A science lab has copper wire coated
with rubber tubing, a plastic vial, and a
pair of cotton gloves. Which of these
materials is not an electrical insulator?
Answer:
the answer is copper wire
For a science project, Janet performs four experiments that are supposed to show a chemical reaction. She displays her results in a table.A 4-column table with 4 rows. The first column titled experiment has entries 1, 2, 3, 4. The second column titled substances has entries water + heat, vinegar + baking soda, cabbage juice + lemon juice, liquid A + liquid B. The third column titled evidence of reaction has entries gas formation, gas formation, color change, precipitate formation. The fourth column titled Chemical Reaction ? has entries yes, yes, yes, yes.In the column titled "Chemical reaction?,” which experiment’s data should be changed to "No”?Experiment 1Experiment 2Experiment 3Experiment 4
Answer:
Experiment 1
Explanation:
I don’t know if this is right
Alcohols have more hydrogen bonding .
(True or False) ?!
Answer:
True
Explanation:
An alcohol is an organic molecule containing an -O-H group. Any molecule which has a hydrogen atom attached directly to an oxygen or a nitrogen is capable of hydrogen bonding.
1. What is the oxidation state of iron in FeC2O4
Answer:
+2
Explanation:
I am first with correct answer
Answer:
the oxidation state of iron in FeC2O4 is +2
what colour is universal indicator when the solution is nuetral?
PLEASE ANSWER ME FAST
Answer:
Green
Explanation:
pH : < 3 = Red
pH : 3 - 6 = Orange or yellow
pH : 7 = Green
pH : 8 - 11 = Blue
If the copper ion just GAINED electrons,
which process did it go through?
Reduction or
Oxidation
What is the main function of a nucleic acid?
A. It allows polysaccharides to form.
OB. It stores lipids inside the proteins.
C. It contains instructions for making proteins.
OD. It is a catalyst in chemical reactions.
The main function of nucleic acid is It stores lipids inside the proteins.
Nucleic acidsNucleic acids are large biomolecules that play essential roles in all cells and viruses. A major function of nucleic acids involves the storage and expression of genomic information. Deoxyribonucleic acid, or DNA, encodes the information cells need to make proteins. A related type of nucleic acid, called ribonucleic acid (RNA), comes in different molecular forms that play multiple cellular roles, including protein synthesis.
Nucleic acids are made of nitrogen-containing bases, phosphate groups, and sugar molecules. Each type of nucleic acid has a distinctive structure and plays a different role in our cells. Researchers who first explored molecules inside the nucleus of cells found a peculiar compound that was not a protein or a lipid or a carbohydrate. It was new. The discovery of this molecule — nuclein, which upon further understanding became nucleic acid — set in motion the eventual discovery of DNA.
Learn more about Nucleic acids
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1) If a chemist has a 5.50 M solution of HCl, how many mL of acid will they need to add to how many mL of water in order to create 20.0 mL of 1.5 M HCl
Answer:
5.4 mL of acid need to be added to 14.6 mL of water.
Explanation:
We can calculate how many mL of acid are needed by using the C₁V₁=C₂V₂ formula:
5.50 M * V₁ = 1.5 M * 20.0 mLV₁ = 5.4 mLThen we calculate how many mL of water have to be added in order to reach 20.0 mL:
20.0 mL - 5.4 mL = 14.6 mLThus, 5.4 mL of acid need to be added to 14.6 mL of water.
What is the volume of a bubble if the original was .25 m^3 at 4 atm and the pressure was reduced to 1 atm?
Answer:
1.00 m^3
Explanation:
Boyles law says that PV = constant, or P1V1=P2V2, while temperature remains constant.
0.25 m^3 *4 atm = V* 1 atm
V = 0.25 m^3 / (1/4)
= 1 m^3
he correct statements about thermal conductivity are: A. The thermal conductivity of metals is generally higher than that of liquids. B. The thermal conductivity of solids is generally higher than that of liquids. C. The thermal conductivity of gases is generally higher than that of liquids.
Answer: The correct statements about thermal conductivity are:
The thermal conductivity of metals is generally higher than that of liquids.The thermal conductivity of solids is generally higher than that of liquids.Explanation:
The rate at which transfer of heat takes place from one object to another by conduction over a unit cross section area of a material is called thermal conductivity.
Hence, more is the distance between atoms of a substance less will be its thermal conductivity. This is because more is the space between molecules of a substance more will be their random motion due to which there will be less effective energy transport.
The thermal conductivity of metals is very high than liquids.
Also, the thermal conductivity of solids is generally higher than that of liquids.
As gases have more space between its molecules so they have less thermal conductivity.
Thus, we can conclude that the correct statements about thermal conductivity are:
The thermal conductivity of metals is generally higher than that of liquids.The thermal conductivity of solids is generally higher than that of liquids.Why did the model of the atom change?
A. New materials became available to build better models.
B. The structure of atoms changed over time.
C. Scientists did not like the original model.
D. Experiments provided new evidence about the atom.
How many atoms in 0.35 moles of Oxygen?
Answer:
11 grams of atoms are in 0.35 moles of oxygen.