Answer:
Explanation:
Sodium chloride has a high melting and boiling point
There are strong electrostatic attractions between the positive and negative ions, and it takes a lot of heat energy to overcome them. Ionic substances all have high melting and boiling points.
Which of the following electronic transitions would emit the lowest energy photon?
B- n=2 to n=1
C-n=3 to n=2
D-n=5 to n=2
Answer:
i will think c-n=3 to NM=2
Calculate the pH after 10.0 mL of 0.125 M NaOH is added to 30.0 mL of 0.105 M HCHO2.
Ka (HCHO2) = 1.8 × 10-4
Answer:
pH = 3.57 after adding 10ml of 0.125M NaOH
Explanation:
NaOH + HCHO₂ => NaCHO₂ + H₂O
=> 10ml(0.125M NaOH) + 30ml(0.030M HCHO₂)
=> 0.01(0.125)mol NaOH + 0.036(0.030)mol HCHO₂ ***(see reference note at end of problem)
=> 0.00125mol NaOH + 0.00315mol HCHO₂
=> (0.00315mol - 0.00125mol) HCHO₂ = 0.0019mol HCHO₂ in excess
+ 0.00125mol NaCHO₂ formed.
HCHO₂ ⇄ H⁺ + CHO₂⁻
C(i): 0.0019mol/0.040L 0.00M 0.00125mol/0.40L
= 0.0475M = 0.0313M
ΔC: -x +x +x
C(eq): 0.0475 - x x 0.0313 +x
Ka = [H⁺][CHO₂⁻]/[HCHO₂] = (X)(0.0313 + x)/(0.0475) = 1.8 X 10⁻⁴
=> x² + 0.03168x + (-8.55 x 10⁻⁶) = 0
Solve with quadratic equation ...
x = 2.68 x 10⁻⁴M = [H⁺] at equilibrium
pH = - log[H⁺] = -log(2.68 x 10⁻⁴) = -(-3.57) = 3.57
___________________________________
*** remember, => moles = Molarity x Volume in Liters
How can high-altitude training help athletes get more oxygen to their cells
Answer:
the altitude in witch the athlete is running candy help them run faster useing less energy
The athletes acclimate to high altitudes, they have more red blood cells which allow their blood to inhale more oxygen.
Does working at higher altitudes increase red blood cells?In high-altitude environments, we breathe less oxygen per breath than at lower altitudes. Each breath delivers less oxygen to the muscles of our body. In higher altitudes, a person is getting used to breathing “thinner” air which can enhance athletes’ athletic performance.
Training at high altitudes, feel like they’re putting forth more effort to perform and they do closer to sea level. The increased rate of exertion is caused by hypoxia, which is a reduction in the amount of oxygen to the muscles to burn fuel and produce energy.
Athletes acquire more red blood cells which offer their blood to hold more oxygen. They get a natural boost to the muscles when additional oxygen is available when they compete at lower altitudes. Therefore, training at high-altitude training help athletes gets more oxygen to their cells.
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A block is pulled 0.90 m to the right in 2.5 s.
What is the block’s average speed to the nearest hundredth of a m/s?
The block’s average speed : 0.36 m/s
Further explanationDistance is the length traveled by an object within a certain of time .
Average speed = total distance/total amount of time ,
Can be formulated :
[tex]\tt avg.s(speed)=\dfrac{\Delta D}{\Delta t}[/tex]
ΔD= total distance
Δt= total time
A block is pulled 0.90 m to the right in 2.5 s :
ΔD= total distance = 0.9 m
Δt= total time = 2.5 s
The block’s average speed :
[tex]\tt avg.s=\dfrac{0.9}{2.5}=0.36~m/s[/tex]
I REALLY NEED HELP can someone help me please I’ll mark you brainliest! :)
Answer:
A
Explanation:
if I am on a bus and I'm relative to A the student sitting next to me B relative to the house the bus goes by?
The waste product of nuclear energy which is a possible pollutant is:
A.smoke
B.hot air
C.radiation
D.heat pollution to lake
Answer:
CCCCCCC
Explanation:
Answer:
C. radiation
Explanation:
the possible pollutant is radiation because nuclear energy causes ; electromagnetic waves are radio waves, light, infrared rays, UV rays, X rays, Gamma rays. These are well known and are used extensively in the fields of communications, industry, medicine and research.
Radiation is a term given for waves caused by electromagnetism and high energy particles .Radioactive substances have High energy particles which are tiny bits of matter that are made to move at high speeds releasing nuclear radiation. There are about 50 naturally occurring radioactive substances and More than 2000 man-made ones. There are three kinds of radioactive radiation – alpha particles, beta particles and gamma radiation.
what is the correct?
Answer:
it is c
Explanation:
How can you get the sugar out of the sweet tea?
Freeze the water and the sugar will appear as clumps inside the ice.
Just let the sweet to stand and the sugar will settle to the bottom of the glass.
Heat the water Cevaporating iD and you will be left with the sugar.
What is the motion of the particles in this kind of wave?
A hand holds the left end of a set of waves. The waves themselves make a larger set of waves in the same direction as that of the smaller waves. A label Wave motion is above the series of waves and an arrow next to the label points right.
The particles will move up and down over large areas.
The particles will move up and down over small areas.
The particles will move side to side over small areas.
The particles will move side to side over large areas.
Answer:
D
Explanation:
The particles will move side to side over large areas.
Answer:
The particles will move side to side over large areas.
Explanation:
how will we know that a chemical reaction happened if we cant see atoms??
we can do soo by noticing any colour change, or by the formation of an insoluble precipitate or by the evolution of a gas.
How many centimeters make an inch?
Answer:
2.54 Centimeters.
I want to prepare 4 Liters of 0.25 M aqueous sodium chloride solution. How many grams of the salt will I need to weigh out?
Answer:
Mass = 58.5 g
Explanation:
Given data:
Volume of solution = 4 L
Molarity of solution = 0.25 M
Grams of NaCl required = ?
Solution:
Formula:
Molarity = number of moles / volume in L
By putting values,
0.25 M = number of moles / 4 L
Number of moles = 0.25 mol/L × 4 L
Number of moles = 1 mol
Mass in gram:
Mass = number of moles × molar mass
Mass = 1 mol × 58.5 g/mol
Mass = 58.5 g
Phenylephrine is a nasal decongestant and is the active ingredient in Sudafed, which contains phenylephrine hydrochloride (PEHCL). The conjugate acid (PEH+) of phenylphrine has a pKa = 5.5. At a physiological pH of 7.4. what is the ratio of concentrations, [PE]/[PEH+]?
Answer:
The ratio of concentrations is 79.4
Explanation:
Using Henderson-Hasselbalch equation we can solve the [PE]/[PEH+] ratio:
pH = pKa + log [A-] / [HA]
Where pH is 7.4
pKa of the phenylphrine is 5.5
[A-] is the weak base = [PE]
And [HA] is the conjugate acid [PEH+]
Replacing:
7.4 = 5.5 + log [PE] / [PEH+]
1.9 = log [PE] / [PEH+]
79.4 = [PE] / [PEH+]
The ratio of concentrations is 79.4
How does heat differ from temperature?
O Temperature is the measure of heat.
O Temperature and heat are the same thing.
O Temperature measures thermal energy, and heat is the flow of thermal eneroy
O Temperature measures the loss of energy, and heat measures the gain of eneray.
Answer: Temperature measures thermal energy, and heat is the flow of thermal energy
Explanation:
Heat describes the transfer of thermal energy between molecules within a system. Heat measures how energy moves or flows. It is measured in Joules.
Temperature measures the hotmess or coldness of a body or how much thermal energy it contains . Temperature describes the average kinetic energy of molecules within a material or system. It is measured in Celsius (°C), Kelvin(K), or Fahrenheit (°F).
Thus the correct option is Temperature measures thermal energy, and heat is the flow of thermal energy
Answer:
its c
Explanation:
edg 2021
5. What percentage of energy generation is
produced by fossil fuels? sc.7.P.11.2
to
(A) 19.5%
B) 33.2%
66.9%
D 86.4%
Answer:
It's actually D. 86.4%
Explanation:
When you combine coal, other gases, petroleum, nuclear, and natural gas, you get 86.4, which is the correct answer.
what's the alkalinity of lemon?
Answer:
Hey mate here's your answer ⤵️
Lemon juice in its natural state is acidic with a pH of about 2, but once metabolized it actually becomes alkaline with a pH well above 7
Hope it was helpfulllwhat is the answer i need help
so it is necessary to place the coefficient 2 in the front of HCL to balance the chemical equation to prove that
we have two CL and two H atoms in the products and one Cl and one H atom in the reactants so if we dont put 2 in front of HCL the chemical equation will not be balanced
Which of the following equations does not represent a redox reaction?
a. NH3+ HCl → NH4Cl
b. 2H2O2+ → 2H2O + O2
c. 2O3 → 3O2
d. 3NO2+ H2O → NO+ 2HNO3
e. LiCl → Li^+ + Cl
Answer:
a. NH3+ HCl → NH4Cl
c. 2O3 → 3O2
Explanation:
A redox reaction is a reaction in which there is loss or gain of electrons. As a result of that , there is a change in the oxidation number of the species involved in the reaction.
If we look at the species shown in the answer, there isn't any change in oxidation number as we move from left to right hence they are not redox reactions.
Redox reactions lead to change in oxidation number of species from left to right.
The half-life for a first-order reaction is 32 s. What was the original concentration if, after 2.0 minutes, the reactant concentration is 0.062 M?
Answer:
0.834 M.
Explanation:
Hello!
In this case, since this is a first-order reaction, we can infer that the half-life and the rate constant are related via:
[tex]t_{1/2}=\frac{ln(2)}{k}[/tex]
Thus, we are able to compute the rate constant:
[tex]k=\frac{ln(2)}{t_{1/2}} =\frac{ln(2)}{32s}\\\\k=0.0217s^{-1}[/tex]
Next, since we have the resulting concentration of the reactant and we need the initial one, we proceed as shown below with the rate law:
[tex]A=A_0exp(-kt)\\\\A_0=\frac{A}{exp(-kt)} \\\\A_0=\frac{0.062M}{exp(-0.0217s^{-1}*2.0min*\frac{60s}{1min} )}\\\\A_0=0.834M[/tex]
Best regards!
Q. Which of the following scenarios describes a process with a negative system entropy change?
A) build a skyscraper
B)An igloo melting
C)A clean room becomes cluttered
D)Osmosis
How many protons are in an element with an atomic number of 8 and mass number of 18
Answer:8
Explanation:
Atomic number = 8
Mass number = 18
The number of protons and the number of electrons is equal to the atomic number.
The number of neutrons in the nucleus is given by the difference in mass number and atomic number.
So, number of protons are 8
number of electrons = 8
number of neutrons = 18 - 8 = 10
Select the keyword or phrase that will best complete each sentence.
a. alkenes
b. -ene-
c. syn and anti
d. alkanes
e. syn
f. nucleophiles
g. -yne-
h. -ane-
i. alkynes
f. electrophiles
g. anti
Compounds that contain a carbon-carbon double bond are known as________
Alkenes are electron rich; therefore, simple alkenes do not react with_______ or bases, but will react with _______or acids.
In the IUPAC system, an alkene is identified by the suffix -ene-
Addition reactions in which two parts Of a reagent are added to the same side of
a double bond are known as _________additions.
Addition reactions in which two parts of a reagent are added from opposite
sides of a double bond are called ________ additions
Halogenation and halohydrin formation occur with ________-additions.
Answer:
alkenes
nucleophiles
electrophiles
syn
anti
syn and anti
Explanation:
Compounds that contain a carbon-carbon double bond are known as alkenes
Alkenes are electron rich; therefore, simple alkenes do not react with nucleophiles or bases, but will react with electrophiles or acids.
In the IUPAC system, an alkene is identified by the suffix -ene-
Addition reactions in which two parts Of a reagent are added to the same side of
a double bond are known as syn additions.
Addition reactions in which two parts of a reagent are added from opposite
sides of a double bond are called anti additions
Halogenation and halohydrin formation occur with syn and anti -additions.
Further explanations:
Compounds that contain a carbon-carbon single bond are known as alkanes. Compounds that contain a carbon-carbon double bond are known as alkenes. Compounds that contain a carbon-carbon triple bond are known as alkynes.
Nucleophiles are electron rich so they react with electron deficient centers while Electrophiles are electron deficient so they react with electron rich centers.
After watching the morning news, roommates Kelly and Rob argued about whether or not a man on trial should have been sentenced to prison for robbing goods and giving to those on welfare. Rob argued that the man should not have been convicted because he broke the law for a good cause while Kelly argued that the man should be convicted because it is against the law to steal so the man's behavior was wrong.
Based on Lawrence Kohlberg's theory of moral reasoning which of the following statements would Kohlberg agree with?
A.
Kelly is at a higher level of moral reasoning than Rob.
B.
Rob is at a higher level of moral reasoning than Kelly.
C.
Rob and Kelly are at the same level of moral reasoning.
D.
Rob has more knowledge than Kelly concerning criminal behavior.
Answer:
B) rob is at a higher level of moral reasoning than kelly
Explanation:
i just took the quiz on edge 2020
Based on Lawrence Kohlberg's theory of moral reasoning statement with which Kohlberg agree with is that Rob is at a higher level of moral reasoning than Kelly.
What is moral reasoning?Moral reasoning is an important and often daily process that people use when trying to do the right thing. For instance, every day people are faced with the dilemma of whether to lie in a given situation or not. People make this decision by reasoning the morality of their potential actions, and through weighing their actions against potential consequences.
A moral choice can be a personal, economic, or ethical one; as described by some ethical code, or regulated by ethical relationships with others. This branch of psychology is concerned with how these issues are perceived by ordinary people, and so is the foundation of descriptive ethics. There are many different forms of moral reasoning which often are dictated by culture.
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What is the purpose of the cooling tower?
A. pumps cool water into the reactor
B. reduces heat pollution to the environment
C. cools down the electric generator
Answer:
id say c though im not sure
Explanation:
Cooling towers are primarily used for heating, ventilation, and air conditioning (HVAC) and industrial purposes.
Answer:
c
Explanation:
i had this on my test
A solution of sulfuric acid (H2SO4, 25.00 mL) was titrated to completion with 34.55 mL of 0.1020 M sodium hydroxide. What was the concentration of the sulfuric acid
Answer:
0.0705 M
Explanation:
We'll begin by writing the balanced equation for the reaction. This is given below:
H₂SO₄ + 2NaOH —> Na₂SO₄ + 2H₂O
From the balanced equation above,
The mole ratio of the acid, H₂SO₄ (nA) = 1
The mole ratio of the base, NaOH (nB) = 2
Next, data obtained from the question. This include the following:
Volume of acid, H₂SO₄ (Va) = 25 mL
Volume of base, NaOH (Vb) = 34.55 mL
Molarity of base, NaOH (Mb) = 0.1020 M
Molarity of acid, H₂SO₄ (Ma) =?
The molarity of the acid, H₂SO₄ can be obtained as follow:
MaVa / MbVb = nA/nB
Ma × 25 / 0.1020 × 34.55 = 1/2
Ma × 25 / 3.5241 = 1/2
Cross multiply
Ma × 25 × 2 = 3.5241
Ma × 50 = 3.5241
Divide both side by 50
Ma = 3.5241 / 50
Ma = 0.0705 M
Therefore, the concentration of the acid, H₂SO₄ is 0.0705 M
Answer:
C=0.140964M
Explanation:
M1V1=M2V2
DATA
M1=?
M2=0.1020M
V1=25.00ML
V2=34.55ML
M*25.00ML=(0.1020M)*(34.55ML)
M*25.00ML=3.5241M*ML
M=3.5241M*ML/25.00ML
M=0.140964M
Therefore, concentration of sulfuric acif is 0.140964M
Perform the following operation
and express the answer in
scientific notation.
4.3x102 -7.0x 102
Answer:
-2.7 ×10²
Explanation:
Scientific notation is the way to express the large value in short form.
The number in scientific notation have two parts.
. The digits (decimal point will place after first digit)
× 10 ( the power which put the decimal point where it should be)
for example the number 6324.4 in scientific notation will be written as = 6.3244 × 10³
Given measurements = 4.3×10² - 7.0 ×10²
= -2.7 ×10²
HELP!!!
Which climate favors mechanical weathering?
dry limate
cold climate
warm climate
desert climate
Explanation:
cold climates hope this helps :)
Answer:
Cold climates
Explanation:
Warm climates favor chemical weathering. Cold climates favor mechanical weathering. Chemical reactions occur faster at higher temperatures.
What do u call a snowman in the summer
Answer:
A puddle
Explanation:
BAHAHAHAHA
PLEASE HELP!!! WILL MARK BRIANLIST DO NOT GUESS I HAVE ATTEMPTED THREE TIMES