When cleaning a buret, begin by coating the inside with NaOH solution most of it out, then drain the rest by opening the stopcock. Rinse with acetone , then hang upside-down on a buret rack.
Why do we rinse burette with solution?To avoid contamination, the burette, like the pipette, should be rinsed with distilled water before filling with the solution.
Rinse the buret with the liquid you intend to use two or three times. Fill the buret with a small amount of liquid, turn the pipet horizontally, and rotate it so that the liquid contacts the entire inside surface of the buret.
Thus, When cleaning a buret, begin by coating the inside with NaOH solution most of it out, then drain the rest by opening the stopcock.
To learn more about the burette, follow the link;
https://brainly.com/question/2957407
#SPJ1
Which of the following sets of changes would definitely result in an originally saturated solution of O2 gas in H2O becoming unsaturated without removing oxygen? Explain why. a. Increase pressure and decrease temperature
b. Decrease pressure and decrease temperature
c. Decrease pressure and increase temperature
d. Increase pressure and increase temperature
The sets of changes would definitely result in an originally saturated solution of O₂ gas in H₂O becoming unsaturated without removing oxygen are Increase pressure and increase temperature. The correct answer is D.
Without removing oxygen, the following modifications would unquestionably cause an initially saturated solution of O₂ gas in water to become unsaturated: Increase the temperature and the pressure.
The increase in intermolecular space that results from heating a saturated solution is caused by an increase in kinetic energy. As a result, the solution becomes unsaturated and more solutes can dissolve in it.
The solubility, which depends on gas pressure, is a measurement of the concentration of dissolved gas particles in the liquid. A gas's solubility increases with increasing pressure because of an increase in collision frequency, while it decreases with decreasing pressure.
Learn more about solubility at https://brainly.com/question/15462976
#SPJ4
Determine the coordination number of the Pb2+ ion in CH3NH3PbI3, which possesses the perovskite structure and has recently been extensively investigated as a new type of solar cell material
The coordination number of the Pb²⁺ ion in CH₃NH₃PbI₃ is 6. It forms an octahedral arrangement with the six iodine atoms surrounding the central Pb²⁺ ion.
What is a coordination number?The coordination number of an ion refers to the number of other ions or molecules surrounding it and coordinating with it through bonds. In the case of cations like Pb²⁺, the coordination number indicates the number of surrounding anions that are coordinated with the cation through ionic bonds.
The coordination number is important in determining the physical and chemical properties of compounds and in understanding their structures and reactivity.
Find out more on coordination number here: https://brainly.com/question/12498196
#SPJ1
1) A sample of an ideal gas has a volume of 2.27 L at 285 K and 1.10 atm. Calculate the pressure when the volume is 1.36 L and the temperature is 306 K.
A sample of an ideal gas has a volume of 2.27 L at 285 K and 1.10 atm. The pressure when the volume is 1.36 L and the temperature is 306 K is 1.77 atm.
What is an ideal gas equation ?
The ideal gas equation is represented as: PV = nRT. In this equation, P refers to the pressure of the ideal gas, V is the volume of the ideal gas, n is the total amount of ideal gas that is measured in terms of moles, R is the universal gas constant, and T is the temperature.
Given:
P1 = 1.10 atm
V1 = 2.27 L
T1 = 285 K
P2 = ?
V2 = 1.36 L
T2 = 306 K
By an ideal gas equation, we get
P2V2/T2 = P1V1/ T1
P2 = T2P1V1/ V2T1
= 306 × 1.10 × 2.27 / 1.36 × 285
= 764 / 387.6
= 1.77 atm
Thus, the pressure when the volume is 1.36 L and the temperature is 306 K is 1.77 atm.
To learn more about an ideal gas equation, follow the link;
https://brainly.com/question/28837405
#SPJ1
Elements with atomic numbers of 104 and greater are known as super-heavy elements. None of these elements have been found in nature but instead have been made in a laboratory. They are very difficult and expensive to create, and they break down into other elements quickly. There currently are no practical applications for any of these elements. However, some scientists believe that, with further work, they may discover some isotopes of super-heavy elements that are more stable and that could possibly have practical implications. Do you think that scientists should continue to try to create super-heavy elements and expand the periodic table? Explain why or why not.
Answer:
Explanation:
Argument for continuing to create super-heavy elements:
-The periodic table is one of the most important and widely used tools in chemistry. Expanding it would increase our understanding of the elements and their properties.
-Discovering new elements and isotopes can lead to unexpected scientific breakthroughs and advancements.
-The creation of super-heavy elements involves cutting-edge technology and scientific expertise, which can push the boundaries of human knowledge and drive innovation.
Argument against continuing to create super-heavy elements:
-The process of creating super-heavy elements is extremely difficult and expensive. There may be more pressing scientific problems that deserve funding and resources.
-The super-heavy elements are highly unstable and break down quickly, so it is unlikely that any practical applications will ever be found.
-The production of super-heavy elements requires the use of high-energy particle accelerators, which can generate hazardous by-products and waste.
As discussed in the introductory text, archaeans do NOT appear to use the Embden-Meyerhof-Parnas (glycolytic) pathway. Instead, they use alternate pathways to metabolize sugars. What is the function of this pathway in organisms that do use it?Choose the best answera. Glucose is used to synthesize two molecules of pyruvate with a net gain of 2 ATP and 2 CO2.b. Glucose is split into two molecules of pyruvate with a net gain of 2 ATP and 2 NADH (regenerated to c. NAD+ to maintain redox balance in the third stage of glycolysis)c. Glucose is split into two molecules of pyruvate, and then fermentation is always used to produce ethanol and CO2.d. Glucose is use to synthesize starch or glycogen with a net gain of 2 ATP and 2 NADH (regenerated to NAD+ to maintain redox balance in the third stage of glycolysis)
The function of the Embden-Meyerhof-Parnas (glycolytic) pathway in organisms that use it is to convert glucose into pyruvate with a net gain of 2 ATP and 2 NADH (regenerated to NAD+ to maintain redox balance in the third stage of glycolysis) (option B).
This pathway takes place in the cytoplasm of cells and is the first stage of cellular respiration. During glycolysis, glucose is split into two molecules of pyruvate, which can then enter the citric acid cycle (also known as the Krebs cycle) for further oxidation and energy production in the presence of oxygen. If oxygen is not available, pyruvate can undergo anaerobic fermentation to produce lactate or ethanol and CO2, depending on the organism.
Learn more about Embden-Meyerhof-Parnas (glycolytic) pathway here: https://brainly.com/question/29604117
#SPJ4
one compound under investigation for use as a lightweight rocket fuel is dimethylhydrazine (60.10 g/mol). it reacts with dinitrogen tetroxide (92.01 g/mol) according to the following reaction:If 150 g of (CH3)2N2H4 react with excess N2O4 at 473 K and 760 torr, what volume of CO2 gas will form?
According to the statement, the volume of [tex]CO_{2}[/tex] Gas is 0.64 L.
The volume of [tex]CO_{2}[/tex] gas that will form if 150 g of [tex](CH_3)2N_2H_4[/tex] reacts with excess [tex]N_2O_4[/tex] at 473 K and 760 torrs can be calculated as follows:
First, calculate the number of moles of [tex](CH_3)2N_2H_4[/tex]:
Number of moles of [tex](CH_3)2N_2H_4[/tex] = (150 g)/(60.10 g/MOL) = 2.5 moles.
Now, calculate the number of moles of [tex]N_2O_4[/tex]:
Number of moles of [tex]N_2O_4[/tex] = 2 × 2.5 moles = 5 moles.
The reaction equation is as follows:
[tex](CH_3)2N_2H_4[/tex] + 2 [tex]N_2O_4[/tex] → 2 [tex]CO_{2}[/tex] + 4 [tex]H_2O[/tex]
From the equation, it can be seen that 1 mole of [tex](CH_3)2N_2H_4[/tex] reacts with 2 moles of [tex]N_2O_4[/tex] to form 2 moles of [tex]CO_{2}[/tex].
Therefore, the number of moles of [tex]CO_{2}[/tex] formed = 2 × 2.5 moles = 5 moles.
Now, use the Ideal Gas Law to calculate the volume of [tex]CO_{2}[/tex] gas formed at 473 K and 760 torrs:
Volume of [tex]CO_{2}[/tex] gas = (5 moles x 0.0821 L atm/mol K × 473 K) / 760 atm = 0.64 L.
Learn more about dimethylhydrazine:
https://brainly.com/question/15008686
#SPJ4
Using the reaction below and your knowledge of limiting reactants, find what mass of iron(II) chloride can be made from 0.60 g of Fe and 0.53 g of Cl2. Round to the nearest 0.01 and remember to include both units and substance in your answer!!! Fe + Cl2 --> FeCl2
The limiting reactant in this reaction is chlorine gas. 0.53 g of chlorine gas will produce about 0.94 g of ferrous chloride.
What is limiting reactant ?A limiting reactant in a reaction is the reactant which is fewer in amount or consume early without complete reaction with other reactants. Hence, as soon as this reactant is consume, the reaction stops.
In the given reaction, one mole of Fe reacts with one mole of Cl₂ gas.
Atomic mass of Fe = 55.8 g/mol
molecular mass of Cl₂ = 71 g/mol
no.of moles in 0.60 g of Fe = 0.60 / 55.8 = 0.010 moles.
no.of moles of 0.53 g of Cl2 = 0.53 /71 = 0.007 moles.
Here, both are needed in equal number of moles, but the number of moles of chlorine gas is fewer hence, it is the limiting reactant.
molar mass of FeCl₂ = 126.8 g/mol
71 g of chlorine gas produce 126.8 g of FeCl₂. Then mass of FeCl₂ produced by 0.53 g of Cl₂.
(0.53g × 126.8 g) /71 g = 0.94 g
Therefore, 0.94 g of FeCl₂ is produced.
Find more on limiting reactants:
brainly.com/question/14225536
#SPJ1
Suppose there are two known compounds containing the generic elements X and Y. You have a 1.00-g sample of each compound. One sample contains 0.27 g of X and the other contains 0.36 g of X. Identify plausible sets of formulas for these two compounds; there can be more than one answer.
A. X2Y and X3Y
B. X3Y and X4Y
C. X4Y2 and X3Y
D. XY3 and XY4
E. XY and X3Y
F. XY and X2Y
G. X2Y5 and X3Y5
B. X3Y and X4Y, B. X3Y and X4Y possible sets of formulas for these two compounds;compounds containing the generic elements X and Y. You have a 1.00-g sample of each compound.
The possible formulas for the two compounds can be determined by considering the ratio of the masses of X to Y in each compound. Since the atomic masses of X and Y are not known, it's not possible to determine the exact formulas of the compounds. However, it is possible to determine the ratios of X to Y in the two compounds.
Given that the first sample contains 0.27 g of X and the second sample contains 0.36 g of X, we can calculate the ratio of X to Y in each sample. If we assume that the two compounds have different formulas, we can assume that the ratio of X to Y in each compound is different. This would give us two different formulas for the two compounds.
Based on this reasoning, the possible answers are B. X3Y and X4Y, E. XY and X3Y, and F. XY and X2Y. All three of these options provide two different formulas with different ratios of X to Y.
Learn more about compound here:
https://brainly.com/question/14117795
#SPJ4
Aqueous hydrobromic acid will react with solid sodium hydroxide to produce aqueous sodium bromide and liquid water . Suppose 28.3 g of hydrobromic acid is mixed with 9.5 g of sodium hydroxide. Calculate the maximum mass of water that could be produced by the chemical reaction. Round your answer to significant digits.
The maximum mass of water that could be produced by the chemical reaction would be 4.32 grams.
Stoichiometric problemsThe balanced equation of the reaction is as follows:
[tex]HBr + NaOH -- > NaBr + H2O[/tex]
mole equivalence of 28.3 g of hydrobromic acid = 28.3/80.91 = 0.35 mol
mole equivalence of 9.5 sodium hydroxide = 9.5/40 = 0.24 mol
Limiting reactant = sodium hydroxide
Mole ratio of sodium hydroxide and water = 1:1
Mole of water produced = 0.24
Mass of 0.24 mol water = 0.24 x 18 = 4.32 grams
In other words, the maximum mass of water that could be produced by the reaction is 4.32 grams.
More on stoichiometric problems can be found here: https://brainly.com/question/14301905
#SPJ1
describe the structure of an atom. identify the three major elementary particles noting their charge and location in an atom.
The three major elementary particles of atom are protons, neutrons and electrons.
An atom is described as a complex arrangement of negatively charged electrons arranged in defined shells about a positively charged nucleus. The nucleus contains most of the atom's mass and basically composed of protons and neutrons, except for common hydrogen which has only one proton.
Generally, atoms consist of three basic particles, protons, electrons, and neutrons. The nucleus present in the center of the atom contains the protons which are positively charged and the neutrons which have no charge. The outermost regions of the atom contains electrons which are negatively charged are called electron shells.
Learn more about atom from the link given below.
https://brainly.com/question/24145478
#SPJ4
Consider the following reaction in aqueous solution: 5Br−(aq)+BrO3−(aq)+6H+(aq)⟶3Br2(aq)+3H2O(l)semantics
If the rate of disappearance of Br–(aq) at a particular moment during the reaction is 0.423 M/s, what is the rate of appearance of Br2(aq) at that moment?
According to chemical equilibrium,the rate of appearance of bromine at that moment is 0.577 M/s.
What is chemical equilibrium?Chemical equilibrium is defined as the condition which arises during the course of a reversible chemical reaction with no net change in amount of reactants and products.A reversible chemical reaction is the one wherein the products as soon as they are formed react together to produce back the reactants.
At equilibrium, the two opposing reactions which take place take place at equal rates and there is no net change in amount of the substances which are involved in the chemical reaction.The rate of appearance of bromine at that moment is 1-0.423=0.577= M/s.
Learn more about chemical equilibrium,here:
https://brainly.com/question/8983535
#SPJ1
If the ΔH = 175 kJ/mol and ΔS = 96 J/K mol for a non spontaneous reaction, at what temperature does this reaction become spontaneous?
Gibbs Free Energy ([tex]\Delta G[/tex]) tells us whether or nor a reaction is spontaneous. If it is negative, it is, and if it is positive, it is not spontaneous.
[tex]\Delta G[/tex] = 0 when a reaction first becomes spontaneous, because it is the first non-positive number.
Solving the QuestionIt is important to note this equation:
[tex]\Delta G = \Delta H-T\Delta S[/tex]
Rearrange the equation to solve for T:
[tex]T=-\dfrac{\Delta G-\Delta H}{\Delta S}[/tex]
Plug in the given information:
[tex]T=-\dfrac{0-175}{0.096}[/tex] (notice how we converted J to kJ)
[tex]T=\dfrac{175}{0.096}[/tex]
[tex]T=1822.9[/tex]
Round to two significant figures:
1800
AnswerAt 1800 K, the reaction will become spontaneous.
A brain scan uses the radioisotope oxygen-15. The recommended dosage is 40 mCimCi. A supply of 260 mCimCi in 40 mL arrives at the lab. How many mL will be injected into a patient?
6.15 ml of 260 mCi will be injected into a patient.
What is radioisotope ?A radioisotope is an unstable form of an element created by bombarding the element with radiation. These unstable elements are known as radioactive isotopes and they continually decay and transform into different elements, releasing energy in the process. Radioisotopes are used in a variety of applications, including medical imaging, medical treatments, industrial processes, environmental monitoring, and scientific research. For example, technetium-99m is used to generate images in nuclear medicine and cobalt-60 is used to treat cancer. Radioisotopes can also be used to detect and measure the presence of pollutants in the environment and to study the origin and age of rocks and fossils.
We can use dimensional analysis to calculate the volume of the radioisotope supply solution that contains the required
40 mCi as follows:
[tex]=\mathrm{\dfrac{40 ml}{ 260 mCi} \times 40 mCi \\}\\[/tex]
[tex]=\mathrm{\dfrac{40 ml}{13 mCi} \times 2mCi \\}\\[/tex]
[tex]=\mathrm{\dfrac{80 ml}{13 } \\}\\[/tex]
= 6.15 ml
Thus, 6.15 ml of 260 mCi will be injected into a patient.
To learn more about radioisotope
https://brainly.com/question/18640165
#SPJ4
A gas has a pressure of 1.43 atm and occupies
a volume of 7.7 L. If the gas is compressed to
a volume of 1.64 L, what will its pressure be,
assuming constant temperature?
According to Boyle's law: P1V1=P2V2
Here
P1=1.43atm:
V2=L:V
1
=
L
⇒
P
2
=
×
⇒
P
2
=
a
t
m
Therefore, the pressure of gas =
The partial pressure of a solution component will always be:
Select the correct answer below:
a. less than its vapor pressure in pure form
b. more than its vapor pressure in pure form
c. equal to its vapor pressure in pure form
d. depends on the substance
The partial pressure of the components of the solution will always be b. more than its vapor pressure in pure form
What is partial pressure?Partial pressure is the pressure exerted by a particular gas in the gas mixture.
Each gas in the mixture exerts an individual pressure which is called partial pressure. The partial pressure of the components of the solution will always be more than their vapor pressure in pure form.
The concept of partial pressure was first conceived by an English meteorologist and chemist named John Dalton. This concept is known as Dalton's Law of Partial Pressure. Reporting from Chemistry LibreTexts, Dalton's partial pressure law reads: "The total pressure exerted by a mixture of gases is the sum of the partial pressures of the component gases".
Learn more about the difference atmospheric partial pressure of oxygen and alveolar partial pressure here :
https://brainly.com/question/29571929
#SPJ4
classify each of the following materials as to whether it is a metal, ceramic, or polymer. justify each choice: (a) brass; (b) magnesium oxide (MgO); (c) Plexiglas; (d) polychloroprene; (e) boron carbide (B4C); and f cast iron.
(a) Brass is an alloy of copper and tin, both of which are metals. So, brass is a metal.
(b) Magnesium oxide is a ceramic as it is an oxide of magnesium.
(c) Consider Plexiglas as polymer as its real name is poly methyl methacrylate or acrylic.
What is polymer ?Polymer is a library of web components that can be used to create user interfaces in web applications. It provides a set of reusable HTML elements, such as buttons, tabs, and sliders, to create interactive user experiences. Polymer uses the latest web technologies such as HTML5, JavaScript, and CSS to create a cohesive web development experience.
It also supports web components and shadow DOM, which allows developers to create custom elements that can be reused across multiple websites. Polymer makes it easy to create custom elements and components, and helps developers create responsive, accessible and maintainable web applications. Polymer is a great tool for creating modern web experiences with minimal effort.
(d) Polychloroprene is a polymer obtained by polymerization of chloroprene.
(e) Boron carbide is ceramic which is used in making bullet proof jackets. It is a combination of boron and carbon.
(f) Cast iron is a metal. It is an alloy of iron and carbon. The percentage of carbon in cast iron is much lesser than that of iron.
To learn more about polymer
https://brainly.in/question/907335
#SPJ4
using the periodic table, identify the name and symbol of the three neutral atoms given their atomic numbers and masses. the neutral atom with an atomic number of 15 15 and a mass number of 31 31 . element name:
The neutral atom with an atomic number of 15 and a mass number of 31 is Phosphorus, with the symbol P.
Phosphorus is an element found in the periodic table with the symbol P and atomic number 15. It is a non-metal and has 5 electrons in its outer shell. It is classified as a non-metal due to its chemistry and the fact that it does not readily form compounds with other elements. Phosphorus is a key component in the production of many important compounds such as fertilizer and phosphoric acid. It is also an important component in the formation of DNA and RNA.
Learn more about the periodic table:
https://brainly.com/question/25916838
#SPJ4
A solution of sodium phosphate is prepared by dissolving 3.95 g of sodium phosphate in water and diluting it to 300.0 mL. What is the Molarity, M, of the salt and each of the ions?
3.95 g of sodium phosphate are dissolved in 300.0 mL of water to create a solution of sodium phosphate. The sodium ions' molality is 1.473 m
As opposed to molality, why is molarity used?Molality is based also on kilograms of solvent, whereas molarity is predicated on the liter of solution. When researching the characteristics of solutions associated to vapor pressure conditions fluctuations, concentrations given in molality are utilized. Because its value is unaffected by temperature fluctuations, molality is employed.
Molarity is moles of solute per litre of solution
Molality is moles of solute per kg of solvent.The volume of solution = 1 L
The mass of solution = volume X density = 1000mL X 1.43 = 1430 grams
The mass of solute = moles X molar mass of sodium phosphate = 0.65X164
mass of solute = 106.6 grams
the mass of solvent = 1430 - 106.6 = 1323.4 grams = 1.3234 Kg
the molality =
Thus molality of sodium phosphate is 0.491 m
Each sodium phosphate of molecule will give three sodium ions.
Thus molality of sodium ions = 3 X 0.491 = 1.473 m
To know more about molality visit :-
brainly.com/question/13031544
#SPJ1
c. 350 mL of water at 32 °C was poured into a 250 mL of water at 84 °C.
The final temperature of this mixture was measured to be 41.33 °C. Is this final temperature possible? Justify your reasoning.
The correct final temperature is 53.7°C
What happens to the temperature of water when mixed?The temperature of water when mixed with another substance will depend on the temperature of the other substance and the amount of energy transferred between the two substances.
If the other substance has a higher temperature than the water, heat energy will flow from the hotter substance to the cooler water, and the temperature of the water will increase until thermal equilibrium is reached.
We know that heat gained = Heat lost
We the have that;
350 * 4.2 * (T - 32) = -250 * 4.2 * (84 - T)
1470T - 47040 = -88200 + 1050T
T = 53.7°C
The final temperature of the mixture is 53.7°C.
Learn more about temperature:https://brainly.com/question/7510619
#SPJ1
which of the following graphs represents the functional relationship between the volume of a gas at constant p and t and its corresponding number of gas moles present in container?
The graph that represents the functional relationship between the volume of a gas at constant pressure and temperature and its corresponding number of gas moles present in the container is the Ideal Gas Law graph.
The Ideal Gas Law states that, at constant pressure and temperature, the volume of a gas is directly proportional to the number of moles of gas present in the container. This relationship can be represented by a straight line on a graph of volume versus number of moles.
The equation for the Ideal Gas Law is:
PV = nRT
where P is the pressure, V is the volume, n is the number of moles of gas, R is the gas constant, and T is the temperature.
learn more about pressure here:
https://brainly.com/question/12152879
#SPJ4
the complete question is:
which of the following graphs represents the functional relationship between the volume of a gas at constant p and t and its corresponding number of gas moles present in container?
difference between coal iron and electric iron
Classify each given species as a strong acid, weak acid, strong base or weak base
KOH, Sr(OH)2, HaPO4, NH3, NaOH, LiOH, HBr, HCl, H2SO4, Ca(OH)2.
Strong base KOH, Sr(OH)2, NaOH, LiOH, Ca(OH)2. Strong acid HBr, HCl, H2SO4. Weak acid H3PO4. Weak base NH3.
KOH - Strong base: KOH is a strong base because it dissociates completely in water to form hydroxide ions (OH-), which are strong bases.Sr(OH)2 - Strong base: Sr(OH)2 is a strong base because it dissociates completely in water to form hydroxide ions (OH-), which are strong bases.H3PO4 - Weak acid: H3PO4 is a weak acid because it only partially dissociates in water to form hydrogen ions (H+) and phosphate ions (PO4^3-).NH3 - Weak base: NH3 is a weak base because it only partially reacts with water to form hydroxide ions (OH-) and ammonium ions (NH4+).NaOH - Strong base: NaOH is a strong base because it dissociates completely in water to form hydroxide ions (OH-), which are strong bases.LiOH - Strong base: LiOH is a strong base because it dissociates completely in water to form hydroxide ions (OH-), which are strong bases.HBr - Strong acid: HBr is a strong acid because it dissociates completely in water to form hydrogen ions (H+) and bromide ions (Br-).HCl - Strong acid: HCl is a strong acid because it dissociates completely in water to form hydrogen ions (H+) and chloride ions (Cl-).H2SO4 - Strong acid: H2SO4 is a strong acid because it dissociates completely in water to form hydrogen ions (H+) and sulfate ions (SO4^2-).Ca(OH)2 - Strong base: Ca(OH)2 is a strong base because it dissociates completely in water to form hydroxide ions (OH-), which are strong bases.To know more about acid please refer:
https://brainly.com/question/29796621
#SPJ4
When the high and low air masses are close together, air moves _____, so wind is ____.
Question 3 options:
faster; stronger
faster; weaker
slower; stronger
slower; weaker
According to the forces of attraction, when the high and low air masses are close together, air moves slow so wind is stronger.
What are forces of attraction?Forces of attraction is a force by which atoms in a molecule combine. it is basically an attractive force in nature. It can act between an ion and an atom as well.It varies for different states of matter that is solids, liquids and gases.
The forces of attraction are maximum in solids as the molecules present in solid are tightly held while it is minimum in gases as the molecules are far apart . The forces of attraction in liquids is intermediate of solids and gases.
Learn more about forces of attraction,here:
https://brainly.com/question/23841038
#SPJ1
Evidence Running puts more pressure on the knee joint and makes muscles work harder than walking. This matters because... (How does this evidence support the claim?)
This matters because it could lead to an increased risk of knee injuries and wear and tear on the joints.
What is the Symptoms Causes of Knee pain?
Common symptoms of knee pain include:
• Pain, which can range from mild to severe and may be worse when walking, running, squatting, and climbing stairs
• Swelling and stiffness
• Difficulty straightening or bending the knee
• Redness or warmth in the joint
• Weakness or instability in the knee
Running puts more pressure on the knee joint and makes the muscles work harder compared to walking, which could lead to an increased risk of knee injuries, such as runner's knee, IT band syndrome, and patellofemoral pain syndrome. Additionally, the increased force can also result in wear and tear on the joints, potentially leading to osteoarthritis later in life. However, it is important to note that running and other high-impact activities can also provide numerous health benefits, including improved cardiovascular fitness, increased muscle strength, and weight management. It's always a good idea to consult with a healthcare professional before starting a new exercise routine, especially if you have a history of joint problems.
Therefore, increased risk of knee injuries and wear and tear on the joints are the answers.
To learn more about Knee pain from the link
https://brainly.com/question/643484
#SPJ1
A solution of ethanol (C2H6O) in water is sometimes used as a disinfectant. 1.00 L of this solution contains 553 g of ethanol and 335 g of water. What is the molality of the ethanol in this solution?
Answer:
The molality of a solution can be calculated by dividing the number of moles of solute (ethanol) by the mass of the solvent (water) in kilograms. To calculate the moles of ethanol, we need to know its molar mass:
C2H6O (ethanol) molar mass = 2(12.01 g/mol) + 6(1.01 g/mol) + 16.00 g/mol = 46.07 g/mol
Next, divide the total mass of ethanol (553 g) by its molar mass (46.07 g/mol) to get the number of moles:
553 g / 46.07 g/mol = 12.0 mol
Next, convert the mass of water (335 g) to kilograms:
335 g / 1000 g/kg = 0.335 kg
Finally, divide the number of moles of ethanol (12.0 mol) by the mass of water in kilograms (0.335 kg) to get the molality:
12.0 mol / 0.335 kg = 35.8 mol/kg (to 3 significant figures)
why the depression in melting and boiling point of manganese and zinc?
The depression in melting and boiling point of manganese and zinc is caused by differences in atomic sizes.
Why the depression?We have to know that the boiling points of the elements that we have in the periodic table can be decided as we look at the periodic properties of the elements in the periodic table.
The depression in the melting and boiling points of manganese and zinc can be attributed to the decrease in the metallic bonding strength as the atomic size increases. Larger atoms have weaker metallic bonds, which leads to a decrease in the melting and boiling points. This trend is known as the atomic size effect.
Learn more about boiling point:https://brainly.com/question/2153588
#SPJ1
20) Which of the following is an ionic compound?
B) PC15
A) SC12
C) C120
D) CH₂0
E) MgCl2
Answer: MgCl₂
Explanation:
Ionic compounds are composed of a metal and a nonmetal.
Mg (magnesium) is a metal and Cl (chlorine) is a nonmetal.
The answer is E) MgCl₂
How much dry solute would you take to prepare each of the following solutions from the dry solute and the solvent?Part A 128 mL of 0.120 M NaNO3.Part B 115 g of 0.220 m NaNO3.Part C 115 g of 1.1 % NaNO3 solution by massExpress your answer using two significant figures
In part A 1.3g dry solute is needed, in part B 2.1 g dry solute is needed and in part C 1.3 g dry solute is needed. This can be calculated using the expression of Molarity.
Volume of sodium nitrate is 128 mL
Molarity of sodium nitrate is 0.120 M
Mass of the sodium nitrate is 115 g
Molality of sodium nitrate is 0.220 m
Percentage of sodium nitrate is 1.1 %
Part A
Moles of NaNO3 = molarity × volume(L)
=0.120M×0.128L=0.01536mole
Mass of NaNO3 = moles × molar mass
=0.01536mole × 84.9947gmole−1
=1.3g
Part B
Moles of NaNO3 = molality × mass of solution(kg)
=0.220m × 0.115kg=0.0253ml
Mass of NaNO3 = moles × molar mass
= 0.0253mole × 84.9947gmole−1
=2.1g
Part C
Mass of NaNO3 =% NaNO3 × mass of solution
= 1.1% × 115g
=1.3g
To learn more about Molarity please visit:
https://brainly.com/question/26873446
#SPJ4
art a classify each process as an endothermic or exothermic process. drag the appropriate items to their respective bins.
Forming solute solvent interaction - Endothermic
Breaking solvent solvent interaction - exothermic
Breaking solute solute interaction - exothermic
What is endothermic and exothermic?Endothermic reactions are reactions that absorb energy from their surroundings, usually in the form of heat. These reactions are characterized by a decrease in temperature and the absorption of heat energy by the reaction. For example, dissolving ammonium nitrate in water is an endothermic reaction because it absorbs heat from the surrounding environment, causing the water to cool.
Exothermic reactions are reactions that release energy to their surroundings, usually in the form of heat. These reactions are characterized by an increase in temperature and the release of heat energy by the reaction. For example, the combustion of a hydrocarbon fuel such as gasoline is an exothermic reaction because it releases heat energy to the surrounding environment, causing the temperature to increase.
Learn more about reaction:https://brainly.com/question/28984750
#SPJ1
A car is travelling at 50.0 miles per hour. Express this speed in kilometers per hour (km/h). (1 mi = 1.609 km)
Answer: 80.45 km/h
Explanation:
50.0 mph x 1.609 =80.45 km/h