Answer:
More energy is released from the old substance than the new substance needs to form its chemical bonds
Explanation:
Chemical A and Chemical B react in an exothermic reaction. When Chemical A and Chemical B are mixed together more energy will be released from the old substance than the new substance will need to form its chemical bonds. Therefore, option B is correct.
What is an exothermic reaction ?When a chemical reaction goes on, energy is shifted to or from the surroundings. When energy is moved to the surroundings, this is called an exothermic reaction, and the temperature of the surroundings increases.
Examples of exothermic reactions are combustion reactions and many oxidation reactions.
A chemical reaction is exothermic if heat is passed by the system into the surroundings. Because the surroundings are deriving heat from the system, the temperature of the surroundings increases.
Thus, option B is correct.
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A buffer solution is made that is 0.347 M in H2C2O4 and 0.347 M KHC2O4.
1. If Ka for H2C2O4 is 5.90E^-2, what is the pH of the buffer solution?
b. Write the net ionic equation for the reaction that occurs when 0.070 mol KOH is added to 1.00 L of the buffer solution.
Answer:
1. pH = 1.23.
2. [tex]H_2C_2O_4(aq) +OH^-(aq)\rightarrow HC_2O_4^-(aq)+H_2O(l)[/tex]
Explanation:
Hello!
1. In this case, for the ionization of H2C2O4, we can write:
[tex]H_2C_2O_4\rightleftharpoons HC_2O_4^-+H^+[/tex]
It means, that if it is forming a buffer solution with its conjugate base in the form of KHC2O4, we can compute the pH based on the Henderson-Hasselbach equation:
[tex]pH=pKa+log(\frac{[base]}{[acid]} )[/tex]
Whereas the pKa is:
[tex]pKa=-log(Ka)=-log(5.90x10^{-2})=1.23[/tex]
The concentration of the base is 0.347 M and the concentration of the acid is 0.347 M as well, as seen on the statement; thus, the pH is:
[tex]pH=1.23+log(\frac{0.347M}{0.347M} )\\\\pH=1.23+0\\\\pH=1.23[/tex]
2. Now, since the addition of KOH directly consumes 0.070 moles of acid, we can compute the remaining moles as follows:
[tex]n_{acid}=0.347mol/L*1.00L=0.347mol\\\\n_{acid}^{remaining}=0.347mol-0.070mol=0.277mol[/tex]
It means that the acid remains in excess yet more base is yielded due to the effect of the OH ions provided by the KOH; therefore, the undergone chemical reaction is:
[tex]H_2C_2O_4(aq) +OH^-(aq)\rightarrow HC_2O_4^-(aq)+H_2O(l)[/tex]
Which is also shown in net ionic notation.
Best regards!
In a vacuum, if a 0.045 kg golf ball is accelerated upward at 2.5 m/s2 by a hair dryer, how much force is required to accelerate the ball?
Answer:
F = 0.553 N
Explanation:
Given that,
Mass of a golf ball, m = 0.045 kg
Acceleration in upward direction, a = 2.5 m/s²
We need to find the force is required to accelerate the ball. Let the force be F. Using the second law of motion as follows :
F = m(a+g)
So,
F = 0.045 (2.5+9.8)
F = 0.553 N
So, the force required to accelerate the ball is 0.553 N.
What is the name of the groups that contain Iron(Fe) and Gold(Au)?
Answer:
Transition Metals
Explanation:
Answer:
Group 8 & 11
Explanation:
Transition Metals
A solution is known to contain either Ni2 or Cr3 . Addition of what single (1 only) reagent would identify which ion is present?
Answer:
Explanation:
From the periodic table; both elements given are from the same group 3.
To test for which ion will be present in the experiment;
We added 6M aqueous sodium hydroxide in excess.
This process is followed by the addition of hydrogen peroxide H2O2 while stirring.
Heat is then applied to the solution.
After we've carried out those process;
We will notice the following;
If[tex]Ni^{2+}[/tex] is present, then a green [tex]NI(OH)_2[/tex] precipitate will be formed
If [tex]Cr^{3+}[/tex] is present,then a yellow-colored [tex]CrO^{2-}_{4}[/tex] will be formed.
How many kilpgrams are in 2.71x10^22 molecules of CO2
Answer:
mass of 1 molecule of CO2=44 g
mass of 2.71*10^22 of CO2=2.71*10^22*44=1.2*10^24g
now to convert grams into kilogram we know that
1000 g=1kg
1.2*10^24=1.2*10^24/1000=1.2*10^21
According to Avogadro's number concept,there are 1.979×10[tex]^-3[/tex] kilograms in 2.71 ×10²² molecules of CO₂.
What is Avogadro's number?Avogadro's number is defined as a proportionality factor which relates number of constituent particles with the amount of substance which is present in the sample.
It has a SI unit of reciprocal mole whose numeric value is expressed in reciprocal mole which is a dimensionless number and is called as Avogadro's constant.It relates the volume of a substance with it's average volume occupied by one of it's particles .
According to the definitions, Avogadro's number depend on determined value of mass of one atom of those elements.It bridges the gap between macroscopic and microscopic world by relating amount of substance with number of particles.
Number of atoms can be calculated using Avogadro's number as follows: mass/molar mass×Avogadro's number. Mass is calculated as, number of molecules/Avogadro's number×molar mass
Substitution in above formula gives, mass=2.71×10²²/6.023×10²³×44=1.979 g or 1.979×10[tex]^-3[/tex] kg.
Thus, there are 1.979×10[tex]^-3[/tex] kg in 2.71×10²² molecules of carbon dioxide.
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In the nucleus of an atom, there are 17 protons and 18 neutrons. What is the atomic number? What is the atomic mass? How many electrons are there?
Answer:
atomic number =17
mass number = 17+18= 35
What is the name of the region (on the graph) where the temperature remains constant while heat is being absorbed (or released)?
Answer:
A heating curve graphically represents the phase transitions that a substance undergoes as heat is added to it. The plateaus on the curve mark the phase changes. The temperature remains constant during these phase transitions.
a box has dimensions 0.2 m x 0.4m x 0.6m. what is the volume of the box in cubic meters?
Answer: 0.048 cubic meters
Explanation:
Volume of a rectangular solid is lxwxh. So you multiply the given dimensions.
Las Vegas, Nevada is in a desert. How does its rapid population growth affect the
water supply? Name at least two specific ways that human activities affect the quality
of groundwater
Answer:
Many areas of the United States experience explosive population growth. The more people that reside someplace, the more demand there is for water there. Often these urban-growth expansions are unplanned and place extraordinary stress on the water supply system, mainly on the groundwater. The stress often depletes groundwater supply, thereby causing wells to dry up. Then water must be brought from somewhere else to support the local population.
Such situations have occurred all over the United States. For example, increased population growth in the southwestern United States has significantly lowered the water table 50 to 200 feet (depending on the area) since the 1940s. Managing urban growth, efforts to reduce water demand, conservation of the resource, and attempts to increase the water supply all address the problem of exceeding water resource limits.
Human activities affect groundwater quality.
Here are some sources and possible solutions to groundwater pollution:
Agriculture—Reduce usage of pesticides and fertilizers.
Landfills—Monitor for leakage and repair linings.
Underground storage tanks—Remove damaged and unused tanks.
Household wastes—Properly dispose of household hazardous waste.
Septic tank leaks—Properly maintain and repair tanks.
Explanation:
This came from the K12 learning course read this and the answer will be there. I underlined the important parts for the answer.
Please it's due today
Answer:
B
Explanation:
Newton's third law. states that:
Action and reaction are equal and opposite.
Which of the following statement best defines matter?
Answer:matter is anything has mass and take up space
Explanation:
Which are the three most common gases Giving Brainliest
Answer:
B
Explanation:
i hope this helps
What can element automatic number tell you about its state of matter
Answer:
Identifies the number of protons a single atom of the element contains.
Explanation:
The atomic number helps people identify elements according to the number of protons one atom of the element has. It essentially defines the element.
While having a neutral charge, it also provides the number of electrons the element has (in one atom).
2. If you travel 7.5 km and walk for 1.5 h. what is your average speed
Show Your Work Actual
Answer:
5km/h
Explanation:
Given parameters:
Distance = 7.5km
Time = 1.5h
Unknown:
Average speed = ?
Solution:
Average speed is the distance divided by the time taken.
Average speed = [tex]\frac{total distance }{time taken}[/tex]
Insert the parameters and solve;
Average speed = [tex]\frac{7.5}{1.5}[/tex] = 5km/h
How many moles of CO are produced when 1.8 moles C reacts?
Express your answer using two significat figures.
5C(s) + 2SO2(g) => CS2(l) +4CO(g)
Answer:
1.44mole of CO
Explanation:
The reaction equation is given as:
5C + 2SO₂ → CS₂ + 4CO
We check to see if the expression is balanced and it is so;
Now;
Given;
1.8mole of C reacted; how many moles of CO are produced;
From the balanced reaction equation:
5 mole of C is expected to produce 4 mole of CO
1.8 mole of C will then produce [tex]\frac{4 x 1.8}{5}[/tex] = 1.44mole of CO
What is the chemical name of the compound NH4SCN?
Its called "Ammonium thiocyanate" Have a great day!! <3
Answer:
it is called Ammonium Thiocyanate or Thiourea
Explanation:
it is made made up of 2 nitrogen atoms, 4 hydrogen atoms, 1 sulfur atom and 1 carbon atom. stay safe and have a great day! TPWK
what is the device to use to measure a potential difference in a circuit called?
Answer:
c. Voltmeter
Explanation:
PLATO LIVES MATTER
What elements in group 17 are solids liquids and gass?
Answer: \(\left( \ce{F} \right)\), chlorine \(\left( \ce{Cl} \right)\), bromine \(\left( \ce{Cl} \right)\), iodine \(\left( \ce{I} \right)\), and astatine \(\left( \ce{At} \right)\)
Explanation:
In the image below if the frisbee represents lights, what does the fence represent?
Answer:
The atmosphere
Explanation:
It reflects and traps the light outside of the Earth's Atmosphere?
I think, hope i helped.
A chemist prepares a solution of copper(II) sulfate by measuring out 17.2 of copper(II) sulfate into a volumetric flask and filling the flask to the mark with water. Calculate the concentration in of the chemist's copper(II) sulfate solution.
Answer:
Concentration of the chemist's copper(II) sulfate solution is 0.43 mol/L
Note: The volume of the flask is assumed to be 250 mL
Explanation:
Since the volume of the volumetric flask is not given, we assume the volume its volume to be 250 mL.
Mass of copper (ii) sulfate = 17.2 g; molar mass of copper (ii) sulfate = 160 g/mol
Concentration in mol/L = number of moles/volume in litres
Number of moles of copper (ii) sulfate = 17.2 g / 160 g/mol = 0.1075 moles
Volume of flask in litres = 250 mL/1000 mL * 1 L = 0.250 L
Concentration = 0.1075 moles / 0.250 L = 0.43 mol/L
Therefore, concentration of the chemist's copper(II) sulfate solution is 0.43 mol/L
Answer:
0.5000
Explanation:
We can measure the concentration of the copper sulfate solution as 1.000 mol/L. Since the tank contains one half liter, the solution contains 0.5000 moles of copper sulfate.
Boron has an average atomic mass of 10.81. One isotope of boron has a mass of 10.012938 and a relative abundance of 19.80%. The other isotope has a relative abundance of 80.20%. What is the mass of that isotope? Report to two decimal places. amu
Answer:
11.01 amu
Explanation:
19.8% • 10.012938 = 1.982561724
10.81 - 1.982561724 = 8.827438276
8.827438276/80.2% = 11.0067808928
Answer: 11.01 amu
Explanation:
Name and write one polyatomic ion with its charge.
Answer:
Because these ions contain more than one atom, they are called polyatomic ions. Polyatomic ions have characteristic formulas, names, and charges that should be memorized. For example, NO3− is the nitrate ion; it has one nitrogen atom and three oxygen atoms and an overall 1− charge.
Polyatomic Ions.
Name Formula
sulfite ion SO32−
Explanation:
explain what happens to temperature and energy as molecules move from gas to liquid to solid
Answer and Explanation:
As the temperature of the substances increases, the average energy of the molecules increases, and average energy of attraction between the molecules decreases consequently intermolecular spacing between the molecules increases. As a result, a substance change in succession from gas to liquid to solid.
net ionic equation of HF(aq)+RbOH(aq)=H2O(l)+RbF(aq)
net ionic equation
H⁺(aq)+OH⁻(aq)⇒H₂O(l)
Further explanationThe electrolyte in the solution produces ions.
The equation of a chemical reaction can be expressed in the equation of the ions
For strong electrolytes (the ionization rate = 1) is written in the form of separate ions, while the weak electrolyte (degree of ionization <1) is still written as an un-ionized molecule
In the ion equation, there is a spectator ion that is the ion which does not react because it is present before and after the reaction
When these ions are removed, the ionic equation is called the net ionic equation
For gases and solids including water (H₂O) can be written as an ionized molecule
So only the dissolved compound is ionized ((expressed in symbol aq)
Reaction
HF(aq)+RbOH(aq)⇒H₂O(l)+RbF(aq)
ionic equation
H⁺(aq)+F⁻(aq)+Rb⁺(aq)+OH⁻(aq)⇒H₂O(l)+Rb⁺(aq)+F⁻(aq)
net ionic equation
H⁺(aq)+OH⁻(aq)⇒H₂O(l)
How many milliliters of an aqueous solution of 0.157 M magnesium nitrate is needed to obtain 17.4 grams of the salt?
Answer:
747mL of the 0.157mL are needed
Explanation:
To find the grams of salt we need to convert these grams to moles using molar mass of magnesium nitrate (148.3g/mol). Then, with the molar concentration we can convert the moles to liters and, as last, to milliliters, as follows:
Moles Mg(NO₃)₂:
17.4g * (1mol / 148.3g) = 0.117 moles of magnesium nitrate
Volume:
0.117 moles * (1L / 0.157moles) = 0.747L
= 747mL of the 0.157mL are needed
In a 0.157M solution there are 0.157 moles per liter of solution
what is the equation for the esterification of glycerol and three palmitic acid
Answer:
Pentyl Ethanoate, CH3COOC5H11, which smells like bananas, is produced from the esterification reaction: CH3COOH(aq) +C5H11OH(aq) → CH3COOC5H11(aq) + H … 2O(l) A reaction uses 3.58g of CH3COOH and 4.75g of C5H11OH and has a yield of 45.00%. Determine the mass of ester that foorms
What is 50% of 36?
O 9
O 16
O 18
O 34
Answer:
18
Explanation:
36 times 0.5
Read the information about the halogen family.
Elements within a group share similar properties. Elements in the halogen family, such as fluorine (F), chlorine (Cl), bromine (Br), and iodine (I), all have seven valence electrons. Iodine is an important element for human health. The thyroid gland uses iodine to produce hormones. One of the hormones it makes is a covalent compound called thyroxine.
Given this information, what effect do you think other halogen elements have on human health? State your prediction, and do some research on one of the halogen elements to see how it affects human health. List your findings, and then give your opinion on whether you think the element you chose should be used in food products, cleaning products, or in other manners that cause it to come in contact with humans. Be sure to provide evidence from your research to support your opinion.
Answer:
See explanation
Explanation:
Chlorine is a member of the halogen family known as a toxic yellowish green gas. Inhalation of chlorine for a prolonged period of time leads to pulmonary edema. If a person comes in contact with compressed liquid chlorine the person may experience frostbite of the skin and eyes.
However chlorine is very useful in water disinfection and is preferred in water treatment because it provides residual disinfection of the treated water.
Chlorine gas may be dissolved in NaOH to form oxochlorate I which is used as a bleach in cleaning.
Answer:
Iodine
Explanation:
iodine is pretty good for you in moderation, iodine can ensure proper tyriod function but too much of it can cause thyroid gland inflammation and thyroid cancer, burning of the mouth, throat, and stomach; and coma.
What type of temperatures and moisture content does Marine time Tropical air have?
Group of answer choices
Cold Temps/ Moist Air
Warm Temps/ Dry Air
Cold Temps/ Dry Air
Warm Temps/ Moist Air
Answer:
D: Warm Temps/ Moist Air
Explanation:
Tropical places usulay have warm mosit air
Maritime Tropical air is associated with warm temperatures and moist air.
Maritime Tropical (mT) air is a type of air mass that forms over warm tropical or subtropical ocean regions. It acquires its characteristics from the ocean's influence, particularly its warm temperatures and high moisture content.
Warm Temperatures: Maritime Tropical air masses originate from regions near the equator or subtropics, where solar radiation is intense and consistently high. As a result, these air masses are typically warm, with temperatures ranging from mild to hot.
The term "Maritime" refers to air masses that have originated from over the ocean, which generally have higher moisture content due to evaporation from the ocean surface. The term "Tropical" indicates that the air mass originates from or near tropical regions, where warm temperatures are prevalent.
Therefore, the correct answer is: Warm Temps/ Moist Air.
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A weather balloon with a volume of 3.40774 L
is released from Earth’s surface at sea level.
What volume will the balloon occupy at an
altitude of 20.0 km, where the air pressure is
10 kPa?
Answer in units of L.
Answer: The volume at an altitude of 20.0 km is 34.5289 L
Explanation:
Boyle's Law: This law states that pressure is inversely proportional to the volume of the gas at constant temperature and number of moles.
[tex]P\propto \frac{1}{V}[/tex] (At constant temperature and number of moles)
[tex]P_1V_1=P_2V_2[/tex]
where,
[tex]P_1[/tex] = initial pressure of gas = 101.325 kPa ( at sea level)
[tex]P_2[/tex] = final pressure of gas = 10 kPa
[tex]V_1[/tex] = initial volume of gas = 3.40774 L
[tex]V_2[/tex] = final volume of gas = ?
Now put all the given values in the above equation, we get the final volume of gas.
[tex]101.325\times 3.40774=10\times V_2[/tex]
[tex]V_2=34.5289L[/tex]
Thus the volume at an altitude of 20.0 km is 34.5289 L
Therefore, the final pressure of the gas will be 3.75 atm