Answer:
Hello your question is incomplete the pH of the solution is unknown hence I will take the pH of the solution be = 4.7
answer : Pka = 5 i.e. > 4.7
Explanation:
Student titrates :
Unknown weak acid ( HA ) with 25 mL of 0.100 M of NaOH ( to a pale pink phenolphthalein endpoint ) then titrates with 11.0 mL of 0.100 M HCL to the solution that contains neutralized unknown acid
Assuming pH of solution = 4.7
HA + NaOH --------> H2O + NaA
at equilibrium point
0.1 * 25 * 1 = n * 1 ∴ [tex]n_{ha}[/tex] = 2.5 mmoles ------ 1
also
[tex]A^-[/tex] + HCL ---------> HA + C[tex]L^-[/tex]
at equilibrium point
[tex]n_{a}[/tex] = 1.1 mmoles --------- 2
The ratio of reaction 2 to 1
[tex]\frac{n_{a} }{n_{ha} }[/tex] = 1.1 / 2.5 ≈ 1/2 ( this show that when the pH = 4.7 approximately half of the A^- have been converted to HA )
Determine the pKa value of the solution
Given that
pH = Pka + log ( A^- / hA )
4.7 = Pka + log ( 1/2 )
therefore Pka = 4.7 - ( -0.3 ) = 5
does lithium violate the octect rule
Answer: Lithium, an alkali metal with three electrons, is also an exception to the octet rule. Lithium tends to lose one electron to take on the electron configuration of the nearest noble gas, helium, leaving it with two valence electrons. There are two ways in which atoms can satisfy the octet rules.
Explanation: Hope this helped! :)
19. A piece of unknown metal with a mass of 62.0g and an initial temperature of 95.3°C is dropped into
100.0g of water with an initial temperature of 27.0°C. The final temperature of the system is 34.0°C.
Answer:
a
Explanation:
13 Consider this neutralization reaction.
H2SO4 + 2KOH → K2SO4 + 2HOH
Which compound is the salt produced in this
reaction?
(1) KOH
(2) H2SO4
(3) K2SO4
(4) HOH
Explanation:
The answer to the question is (3) K2SO4
Give the electronic configuration of an atom of sulfur.
Answer:
1s² 2s² 2p⁶ 3s² 3p⁴
Explanation:
Looking at the periodic table, we see that sulfur (S) has an atomic number of 16, this means its electronic configuration would be:
1s² 2s² 2p⁶ 3s² 3p⁴We know the electronic configuration written above is correct because the sum of all the superscript numbers is 16 (2+2+6+3+4=16).
1. A wave has a frequency of 800 Hz and a wavelength of 2000 cm. What speed
is this wave traveling?
Answer:
V=f*(wavelength)
V= (800)(20m)
16000m/s
Explanation:
Which organ detects stimuli from the environment and is part of the nervous system?
Group of answer choices
A. eye
B. stomach
C. heart
D. lungs
It's the eye because it's the organ of sight
precautions of a radioactive decay lab ?
Answer:
Don't touch radioactive waste with bare hands
Don't eat the radioactive thing
Wear protective eyewear
Wear lab coat/gloves
Explanation:
https://ehs.princeton.edu/laboratory-research/radiation-safety/radioactive-materials/handling-radioactive-materials-safely
Princeton article
1 mole of any gas is equivalent to?
Answer:
22.4 L at standard temperature and pressure.
How are cations formed? A. when one or more electrons of an atom disintegrate B. when an atom gains one or more electrons from other atoms C. when an atom shares one or more electrons with another atom D. when an atom loses one or more electrons
Answer:
D
Explanation:
When an atom loses an electron the number of electrons exceeds the number of protons. This means that the negative charge induced by the electrons exceeds the positive charge induced by the protons.
What is the molarity of a solution made from dissolving 3.0 moles of Saline (NaCl) in 0.25 L of solution?
Answer: the answer is 12M
Explanation: 3.0mol/ 0.25L =12M
12M is the molarity of a solution made from dissolving 3.0 moles of Saline (NaCl) in 0.25 L of solution.
What is molarity?The amount of molecules of molecules divided by the quantity of liters in solution is the definition of molarity, a concentration unit in chemistry. It is crucial to comprehend how it is calculated as well as when to employ it in comparison to other units because it is among the most widely used concentration units.
A chemical solution's concentration is measured in molarity (M). It refers to the solute's moles per liter of solution. To be clear, this is not the same as the liters of solvents (a common mistake).
molarity = number of moles of solute/ volume of solution in litre
molarity =3.0mol/ 0.25L
=12M
Therefore, 12M is the molarity of a solution made from dissolving 3.0 moles of Saline (NaCl) in 0.25 L of solution.
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if 13 moles of Fe react, what is the mass of FeS produced?
Answer:
1144 g of FeS
Explanation:
We'll begin by writing the balanced equation for the reaction. This is illustrated below:
Fe + S —> FeS
From the balanced equation above,
1 mole of Fe reacted to produce 1 mole of FeS.
Therefore, 13 moles of Fe will also react to produce 13 moles of FeS.
Finally, we shall determine mass of 13 moles of FeS. This can be obtained as follow:
Mole of FeS = 13 moles
Molar mass of FeS = 56 + 32
= 88 g/mol
Mass of FeS =?
Mass = mole × molar mass
Mass of FeS = 13 × 88
Mass of FeS = 1144 g
Therefore, 1144 g of FeS were obtained from the reaction.
Why does an ice cube melt when you hold it in your hand?
Your hand transfers temperature to the ice cube.
Heat from the ice cube is transferred to your hand.
Heat is transferred from your hand to the ice cube.
The ice cube radiates heat to your hand.
heat is transferred from your hand to the ice cube
Answer:
Heat is transferred from your hand to the ice cube.
CaC2(s) + 2H2O(l) --> Ca(OH)2(aq) + C2H2(g) In the reaction above, 0.5487 grams of calcium carbide are completely consumed to produce acetylene gas, C2H2. What volume (in mL) will this gas occupy if it is collected at 43 degrees Celsius and 0.926 atm pressure
Answer:
239.7mL
Explanation:
Using the general gas equation;
PV = nRT
Where;
P = pressure (atm)
V = volume (L)
n = number of moles (mol)
R = gas constant (0.0821 Latm/molK)
T = temperature (K)
The balanced chemical equation in this question is as follows:
CaC2(s) + 2H2O(l) --> Ca(OH)2(aq) + C2H2(g)
From the equation, 1 mole of CaC2 produces 1 mole of ethylene gas, C2H2.
Using mole = mass/molar mass
Molar mass of CaC2 = 40 + 12(2)
= 40 + 24
= 64g/mol
mole = 0.5487/64
mole = 0.00857mol of CaC2
Hence, 0.00857mol of CaC2 produced 0.00857mol of C2H2
Based on the information provided, n = 0.00857mol, T = 43°C = 43 + 273 = 316K, p = 0.926 atm
PV = nRT
V = nRT/P
V = 0.00857 × 0.0821 × 316/0.926
V = 0.222/0.926
V = 0.2397L
In mL, volume = 0.2397 × 1000
= 239.7mL
Un compuesto contiene un peso de 40% de carbono, 6.7% de hidrógeno y 53.3% de oxígeno una muestra de 0.10 moles de este compuesto pesa 6.0g la formula molecular del compuesto es
Answer:
[tex]C_2H_4O_2[/tex]
Explanation:
¡Hola!
En este caso, dado que conocemos la composición porcentual del compuesto, es posible primero obtener la formula empírica al asumir que dichos porcentajes son gramos, que se vuelven moles con las masas atómicas de carbono, hidrógeno y oxígeno respectivamente:
[tex]n_C=40gC*\frac{1molC}{12.01 gC}=3.33molC \\\\n_H=6.7gH*\frac{1molH}{1.01gC}=6.6molH\\\\n_O=53.3gO*\frac{1molO}{16.00gO}=3.33molO[/tex]
De este modo, ahora obtenemos las relaciones molares entre ellos, con el fin de obtener los subíndices en la fórmula empírica:
[tex]C:\frac{3.33}{3.33}=1\\\\ H:\frac{6.6}{3.33}=2\\\\O:\frac{3.33}{3.33}=1[/tex]
Por consiguiente, la fórmula empírica es:
[tex]CH_2O[/tex]
Finalmente, dado que la masa molar del compuesto es 6.0/0.10=60g/mol (dada la masa y las moles), es posible notar que como la masa molar de la fórmula empírica es 30; esta es dos veces la molecular, por lo que esta ultima resulta:
[tex]C_2H_4O_2[/tex]
¡Saludos!
Which of the following MOST influences a major
shift in how the entire nucleotide sequence is
read?
А
base-pair substitutions and point mutations
B
silent mutations and nonfunctioning proteins
С
missense mutations and nonsense mutations
D
base-pair insertions and deletions
Answer:
Which of the following MOST influences a major
shift in how the entire nucleotide sequence is
read?
А base-pair substitutions and point mutationsB silent mutations and nonfunctioning proteins
С missense mutations and nonsense mutations
D base-pair insertions and deletions
Among the given disorders, missense mutations and nonsense mutations which mostly influences the shift in entire nucleotide.
What is mutation?A nucleotide is made of ribose sugar, phosphate groups and base pairs. Each base have a complementary base to which it pairs. If any disorder occurs in the base pairing or coding in nucleotide it is called the mutation.
A missense mutation is a sort of point mutation or single base mutation that alters the DNA by replacing one nucleotide of the codon with another nucleotide, thus changing the amino acid that is coded for in the protein.
A nonfunctional protein may emerge from the substitution of an amino acid, or the protein may not be impacted at all. Whether the mutational alterations are "conservative" or "nonconservative" will determine the functionality of the resulting protein.
It's interesting to note that the mutation is known as a nonsense mutation when the alteration in the codons nucleotide causes the development of the stop codon. The nonsense mutation causes the premature end of protein synthesis as a result of the creation of the stop codon.
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The half-life of tritium (H-3) is 12.3 years. If 48.0mg of tritium is released from a nuclear power plant during the course of a mishap, what mass of the isotope will remain after 49.2 years?
Answer:
Explanation:
it is tough question plz give me some time i would give you your ans soon
See photo! Calculating mass and percentage yields.
Answer:
see above
Explanation:
check for cfe's
8. If a chemical reaction such as photosynthesis begins with 6 atoms of carbon (C), how many atoms of carbon (C) should be in the products? A. 12 atoms of carbon (C) B. 6 atoms of carbon (C) c. 3 atoms of carbon (C) D. 2 atoms of carbon (C)
A. 12 atoms of carbon (C)
B. 6 atoms of carbon (C)
C. 3 atoms of carbon (C)
D. 2 atoms of carbon (C)
Answer
b
Explanation:
Which of the following elements will have its valence electrons represented as in Figure A?
I. Oxygen and Sulfer
II. Selenium and Tellurium
III. Polonium only
A. I only
B. II only
C. III only
D. I, II, and III
Magnesium sulfate + Zinc - ?
How does the ocean affect coastal climate?
O A. The specific heat keeps the ocean temperatures more even.
B. The specific heat capacity makes the coast colder in winter.
C. The specific heat keeps the coast region warm year-round.
O D. The specific heat keeps warm air constantly blowing inland.
Lo
Answer:
A. The specific heat keeps the ocean temperatures more even.
Explanation:
I just took a test on a p e x and it was correct! :)
Give me lil reasoning so I know your not lying for points
:(
(I’ll mark you as brainlister )
Answer:
0.01 psi
Explanation:
If you look at the data points plotted on the graph, the slope of the line touches 0.1 for the y-axis when it is at 20 for the x-axis.
list 2 ways mechanical energy can be transformed into non-mechanical energy ?
Answer:
One is the classic example of friction. When two surfaces rub together, they generate thermal energy, or heat. This is a transformation of the mechanical kinetic energy of the objects into the thermal non-mechanical energy (which is small-scale kinetic energy).
Mechanical energy can be used to overcome friction or lost in form of heat in machine parts. Friction and heat are two non-mechanical energy.
Transformation of mechanical energy into non mechanical energy
Based on the principle of conservation of energy, energy can neither be created nor destroyed but can be transformed from one form to another.
Two ways mechanical energy can be transformedThe two ways mechanical energy can be transformed include the following;
FrictionHeatMechanical energy can be used to overcome friction or lost in form of heat in machine parts, in this process, the mechanical energy (kinetic energy) would be converted into other forms of energy such as heat.
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Use your knowledge of atoms, bonding, and the periodic table to complete the chemical equation .”CH4 + O2
and predict the products of the chemical reaction on your paper. Label this equation “Initial Prediction.
Answer:
CH4 + O2 = CO2 + H2O.
Answer:
CH4 + O2 = CO2 + H2O.
Explanation:
A 6.0-V battery does 1200 J of work transferring charge. How much charge is transferred?
answer is below!! hope this helped
A 6.0-V battery does 1200 J of work transferring charge, then 100C charge is transferred.
What is battery ?One or more electrochemical cells with external connections for powering electrical equipment make up an electric battery, which is a source of electric power.
A battery's positive terminal serves as the cathode and its negative terminal serves as the anode when it is delivering electricity.
Electricity is accepted, stored, and released on demand by batteries and similar devices. Like many other common energy sources, batteries store energy through chemistry in the form of chemical potential.
For instance, until they are burned, logs store energy in their chemical bonds for later conversion to heat.
V = 12 V
W = 1200 J
q = ?
V = W / q
12 = 1200 / q
q = 100 C
Thus, A 6.0-V battery does 1200 J of work transferring charge, then 100C charge is transferred.
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Growing the same crop on the same field year after year
A)
enriches the soil content.
B)
promotes a higher plant yield.
C)
raises the risk of increasing the number of pests in that area.
D)
guarantees that the plants will intake all the fertilizers applied.
Answer: The answer is D,
Why is it important to know characteristics that matter undergoes in chemistry? How can we analyze the relationships between chemical and physical changes and properties?
Extension Questions: What is the study of Chemistry? Who are some of the important people who have contributed to the field? How do regular Americans interact with Chemistry around them?
How can we understand the historical development of the Periodic Table and apply its predictive power?
Extension Questions: Describe different chemical principles and systems. How does the layout of the periodic table allow you predict other element's properties? Consider all types and groups of elements.
Why is it important to know and understand the historical development of atomic theory?
Extension Questions: How does the atom relate to the elements of the periodic table? What are your most common models and how do they relate to the current atomic model? What theories don’t hold true today if any?
How do atoms combine to form ionic, covalent, and metallic bonds?
How can we write and balance chemical equations using the law of conservation of mass?
Answer:
Chemistry is important because everything you do is chemistry! Even your body is made of chemicals. Chemical reactions occur when you breathe, eat, or just sit there reading. All matter is made of chemicals, so the importance of chemistry is that it's the study of everything.
helpp!!
how much energy is required to heat up 100.0 grams of water from 0.000C to 60.00C?
Answer:
25,104
Explanation:
100.0 x 4.184 x 60.0 = 25,104
Energy required to heat up 100 grams of water(4.184J/g°C) from 0.000C to 60.00C is 25,104.
What is Thermodynamics?The science of thermodynamics examines the connections between heat, work, temperature, and energy. The rules of thermodynamics explain how energy moves inside a system and whether or not the system is capable of performing beneficial work on its surroundings. The heat needed to increase one gram of a substance's temperature by one degree Celsius is known as specific heat capacity.
Here,
The specific heat capacity of water is 4.184 J/g° C
This is the heat required to increase the temperature by 1°C.
same way, 4.186J is heat required to raise the temp of 1 gram of water.
Derived equation is: q = mcΔT
Where,
q is heat required
c is specific heat capacity of the substance
m is mass of the substance and
ΔT is the change in temperature
Given,
m = 100g
ΔT = 60.00C - 0.00C
ΔT = 60°C
c = 4.184 J/g°C
now, substitute the values:
q = mcΔT
q = 100 × 60 × 4.184
∵ q = 25,104
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classify the following elements under metals, non metals and metalloids, boron, zinc Mercury, silicon, oxygen, nitrogen, sodium
Answer:
Zinc mercury transition metal
Silicon boron metalloid
Oxygen nitrogen non metal
Sodium alkali metal
Explanation:
If an electron has an acceleration of 2.33 × 102 m/sec2, what is this value in units of m/min2?
Answer:
The electron has an acceleration of 838800 [tex]\frac{m}{min^{2} }[/tex]
Explanation:
An electron has an acceleration of 2.33*10² [tex]\frac{m}{sec^{2} }[/tex]
To be able to express in units [tex]\frac{m}{min^{2} }[/tex], you must carry out the conversion taking into account that 1 [tex]\frac{m}{sec^{2} }[/tex]= 3600 [tex]\frac{m}{min^{2} }[/tex]. Then you can apply the following rule of three: if 1 [tex]\frac{m}{sec^{2} }[/tex] equals 3600 [tex]\frac{m}{min^{2} }[/tex], 2.33 * 10² [tex]\frac{m}{sec^{2} }[/tex] equals how much [tex]\frac{m}{min^{2} }[/tex]?
[tex]\frac{m}{min^{2} }=\frac{2.33*10^{2} \frac{m}{sec^{2} }*3600\frac{m}{min^{2} }}{1\frac{m}{sec^{2} }}[/tex]
[tex]\frac{m}{min^{2} }=838800[/tex]
The electron has an acceleration of 838800 [tex]\frac{m}{min^{2} }[/tex]