Answer:
The melting point determination may need improvement- it may not have been done properly, and make sure it was repeated at least once.
Explanation:
Given that we know the actual melting point of pure acetylsalicyclic acid to be 135°, it follows that the process followed to obtain the melting point range of 114 to 125 degrees Celsius must be inaccurate.
Therefore, we can conclude that, the melting point determination may need improvement. It may not have been done properly, and we must make sure it is repeated at least once.
What is known about a reaction with a negative enthalpy?
A. The reaction is endothermic,
B. The reaction is spontaneous,
C. The reaction is exothermic,
D. The reverse reaction is favored,
Considering the definition of enthalpy of reaction, the correct answer is option C. a reaction with a negative enthalpy indicates that the reaction is exothermic.
Definition of enthalpy of reactionThe enthalpy of a chemical reaction as the heat absorbed or released when chemicals are transformed into a chemical reaction and it occurs at constant pressure.
The enthalpy is an extensive property, that is, it depends on the amount of matter present.
Finally, it must be taken into account that:
A reaction is called exothermic if its enthalpy of reaction is negative (that is, if the system gives up heat).A reaction is called endothermic if its enthalpy of reaction is positive (that is, if the system absorbs heat).SummaryIn summary, a reaction with a negative enthalpy indicates that the reaction is exothermic.
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Energy in the amount of 420 J is added to a 35 g sample of water at a temperature of 10°C. What is the final temperature of the water?
The final temperature of the water, T2 = 38.57°C
Temperature can be defined as a measure of the degree of hotness or coldness of a physical object (body). Thus, it is measured with a thermometer and its units are degree Celsius (°C), Fahrenheit (°F) and Kelvin (°K).
A calorie refers to the amount of heat required to raise the temperature of a gram of water by one (1) degree Celsius (1°C).
Given the following data:
Quantity of energy = 420JMass = 35 gramsInitial temperature, T1 = 10°CThe specific heat capacity of water is 4.2 J/g°C.
To find the final temperature of the water (T2):
Mathematically, the quantity of energy (heat capacity) is given by the formula;
[tex]Q = mcdt[/tex]
Where;
Q represents the heat capacity or quantity of heat.M represents the mass of an object.C represents the specific heat capacity of water.dt represents the change in temperature.Substituting the values into the formula, we have;
[tex]420 = 3.5 \; * \; 4.2 \; * \; dt[/tex]
[tex]420 = 14.7 \; * \; dt\\\\dt = \frac{420}{14.7}[/tex]
Change in temperature, dt = 28.57°C
Next, we would solve for the final temperature by using this formula;
[tex]dt = T2 - T1[/tex]
[tex]28.57 = T_{2} - 10\\\\T_{2} = 28.57 \; + \; 10\\\\T_{2} = 38.57[/tex]
Final temperature, T2 = 38.57°C
Therefore, the final temperature of the water, T2 is equal to 38.57°C
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what is the requirements to obtain citizenship?
please answer it correctly
Answer:
Age. ...
Residency. ...
Residence and Physical Presence.
Good Moral Character.
Attachment to the Constitution.
Language.
U.S. Government and History Knowledge.
Oath of Allegiance.
These are some requirements for obtaining citizenship .
precautive measures taken when using pooter
I guess ensuring that you don't suck the insects or specimen collected by ensuring there is a net in the pooter
The atomic number of silicon (Si) is 14. What's the electron configuration for silicon? Question 1 options:
A) [Ar] 3p5
B) [He] 1s2 2p6
C) [Ne] 3s2 3p2
D) [He] 2s2 3p2
Answer:
D.[Ne] 3S2 3P2
Explanation:
The electron configuration for silicon is [Ne] 3s² 3p². Hence Option (C) is correct.
What is elctronic configuration ?Electronic configuration, also called electronic structure or electron configuration, the arrangement of electrons in orbitals around an atomic nucleus.
The electron configuration of an element describes how electrons are distributed in its atomic orbitals.
Electron configurations of atoms follow a standard notation in which all electron-containing atomic subshells (with the number of electrons they hold written in superscript) are placed in a sequence.
Silicon belongs to group 14th and 3rd period.Therefore, The electron configuration for silicon is [Ne] 3s² 3p². Hence Option (C) is correct.
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Patience, a popular card game in Mendeleev's time, is also known as Go Fish.
A. True
B. False
Answer:
B. False
Explanation:
step by step explanation
Answer:
False
Explanation:
is (H) a positive or negative value
Answer:
A chemical reaction that has a positive ΔH is said to be endothermic , while a chemical reaction that has a negative ΔH is said to be exothermic . What does it mean if the ΔH of a process is positive? It means that the system in which the chemical reaction is occurring is gaining energy.
The lattice energy for an ionic compound cannot be measured directly but can be calculated from the Born-_____ cycle, using a series of individual steps for which all enthalpies are known except for the lattice energy. This method is an application of Hess's law which, states that the overall energy change for a process is given by the _____ of the enthalpy changes for the individual steps.
Answer:
first is HABER
second is SUM
Explanation:
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question 8 chemistry help
Answer:
Sorry,I can't do this because i don't know this questions answer.
why can't sodium salt be prepared by double decomposition
Sodium salt might not be prepared by double decomposition because the method is used in preparing insoluble salts.
What is Double decomposition method?Double decomposition method serves as the method that is used in preparing compounds which entails reaction between two soluble compounds and after reaction soluble and insoluble products are produced.
Therefore, since most of the sodium salt are soluble salt , Double decomposition cannot be used to prepare them.
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5. What change would increase the amount of gas able to be dissolved in a given amount of liquid water? (2 points)
Increasing temperature
a
Increasing pressure
Increasing surface area
O
Increasing rate of stirring
answer : increasing pressure
the amount of gas that can be dissolved in liquid water increase with the increase in pressure
Answer:
increasing pressure
Explanation:
Which of the following is the best definition of a physical property?
A. Tearing paper in half.
B. Something that can be observed or measured while changing the identity of the substance.
C. The ability of something to undergo a change or reaction.
D. Something that can be observed or measured without changing the identity of the substance.
Answer:
D.Something that can be observed or measured without changing the identity of the substance.
what are your thoughts on Galileo's idea about motion? i need the answer pls
Answer:
Galileo believed that a projectile is a combination of uniform motion in the horizontal direction and uniformly accelerated motion in the vertical direction. If it is not impeded, it will continue to move even without an applied force
What is the molarity of 2 moles of a compound dissolved in 4 L of water?
A. 2 M
B. 0.5 M
C. 4M
D. 1 M
Answer:
[tex]\boxed {\boxed {\sf B. \ 0.5 \ M}}[/tex]
Explanation:
Molarity is a measure of concentration in moles per liter. The formula for calculating molarity is:
[tex]molarity= \frac{moles \ of \ solute}{ liters \ of \ solution}[/tex]
There are 2 moles of a compound or the solute. There are 4 liters of water or the solution.
moles of solute= 2 mol liters of solution = 4 LSubstitute the values into the formula.
[tex]molarity = \frac{ 2 \ mol}{ 4 \ L}[/tex]
Divide.
[tex]molarity= 0.5 \ mol /L[/tex]
1 mole per liter is equal to 1 Molar, so the solution's molarity of 0.5 mol/L is equal to 0.5 M.
[tex]molarity = 0.5 \ M[/tex]
The molarity of the solution is 0.5 Molar and choice B is correct.
what is meant by reactive elements
Answer; relative elements are most reactive elements and compounds may ignite spontaneously or explosively. They generally burn in water as well as the oxygen in the air
Explanation:
Answer:
Reactive elements are the elements which are ready to gain electrons because they have incompletely filled outermost shell.
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what is the formula of water
Answer:
The formula of water is H20
career in chemistry list ten
Explanation:
Chemistry Teacher.
Chemical Engineer.
Forensic Scientist.
Geochemist.
Biochemists
Pharmacologist
Analytical Chemist
Envionmental chemist
Water Chemist
Catalysis
What is Spontaneous ion
which of the following statements is true about alkali?
A) bases that soluble in water
B) shows a pH value less than 7
C) Ionises in water to form hydroxonium ions
D) Reacts with carbonate salt to release carbon dioxide gas
Answer:
it should be letter c
Explanation:
I hope this help
in order to decrease the freezing point of 500. g of water to 1.00° c how many grams of ethylene glycol (C2H602)must be added (KF=1.86°C kg solvent)
Answer:
if wrong sorry ok????
Three Balanced equations for Ammonium salt+Alkali=Salt+water+carbon dioxide
Answer:
NH₄Cl (aq) + NaOH (aq) -> NaCl (aq) + H₂O (l) + NH₃ (g)
(NH₄)₂CO₃ (aq) + 2KOH (aq) -> K₂CO₃ (aq) + 2H₂O (l) + 2NH₃(g)
NH₄NO₃ (aq) + LiOH (aq) -> LiNO₃ (aq) + H₂O (l) + NH₃ (g)
Explanation:
The gas liberated when an alkali reacts with an ammonium salt is NH₃ (ammonia), not CO₂.
is riding a bike or bus quicker way to get to school?
IV:_____________
DV:____________
Hypothesis:________________________________________________
Environmental scientists are unconcerned with methods to preserve natural resources.
Please select the best answer from the choices provided
T
F
Answer:
False
Explanation:
1. In regards to curly hair, which of the following statements
are TRUE? (select 2 answer choices).
A. Curly hair develops over time. It is not acquired at birth.
B. Curly hair can lead to harmful mutations in the body.
C. Curly hair results from a change in the gene that
codes for hair structure.
D. People with curly hair have different hair protein structures than people with
straight hair.
Answer here:
Answer:
A and D are the answers
Explanation:
the other two don't make sense
The statements C and D are correct, i.e., curly hair have different protein structure from straight hair and curly hair results from a change in the gene.
What is protein?Proteins are biomolecules made of amino acids. Proteins are very essential to all living things and contributes the body structure. Proteins are mainly up taken through diet and they are the main source of energy.
Hair is made of keratin protein. Keratin makes up our skin and nails too.Curly hair is originating by birth not developing over time. Curly hair is more likely to be occurring through inheritance.
The protein structure the hair follicle is some more bend for curly hair. Curly hair and straight hair originates from different gene traits. The gene type is inherited from the parents.
Hence, for people with curly hair have different protein structure and it result from a change in gene that code for hair structure. Thus options C and D are correct.
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What does the prefix trans-indicate?
A. There are at least two double bonds in the molecule.
B. The carbons on either side of the double bond are pointed in
opposite directions.
C. The molecule is an alkane with no double bonds.
O D. The carbons on either side of the double bond are pointed in the
same direction
Answer:
B. The carbons on either side of the double bond are Pointed in opposite directions
What can form as a result of a chemical reaction?
Answer:
It form new chemical from chemical reaction
Answer:
Product
Explanation:
Question 6 of 10 What is the function of mitochondria? O
A. The mitochondria use sugars as fuel to produce energy.
B. The mitochondria direct the cell's activities and hold its DNA.
C. The mitochondria surround the cell and control which materials come into and out of the cell.
D. The mitochondria use sunlight to produce sugars. SUBE
Answer:
A. The mitochondria use sugars as fuel to produce energy.Explanation:
The most prominent function of mitochondria is to produce the energy currency of the cell, ATP (i.e., phosphorylation of ADP), through respiration and using sugar as fuel, and to regulate cellular metabolism .
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why water can reduce unpleasant smell that produce from methane gas ?
Answer:Water contains Oxygen the purified the methane gas
Explanation:
Question 5: thanks you
Answer:
A linear molecule has a bond angle of 180°
