Answer:
65.8mL of water and 184.2mL of the 95% EtOH stock solution must be added.
Explanation:
To solve this question we need to find hoy many times the 95% EtOH must be diluted to obtain a 70% EtOH solution. That is:
95% / 70% = 1.357 times the solution must be diluted.
If we want to make 250mL of the diluted solution, the amount of 95% that must be added is:
250mL / 1.357 times =
184.2mL of the 95% solution must be added
And of water:
250mL - 184.2mL = 65.8mL of water
What are metalloids?
A metalloid is a type of chemical element which has a preponderance of properties in between, or that are a mixture of, those of metals and nonmetals.
Answer:
Metalloid, in chemistry, an imprecise term used to describe a chemical element that forms a simple substance having properties intermediate between those of a typical metal and a typical nonmetal. There is no single property which can be used to unambiguously identify an element as a metalloid.
What is the specific heat of a 44 g piece of metal if 202 Joules of heat are required to
raise the temperature from 22ᵒC to 33.6ᵒC?
Answer:
≈ 395,8 J/(kg * °C)
Explanation:
m = 44 g = 0,044 kg
[tex]t_{1}[/tex] = 22 °C
[tex]t_{2}[/tex] = 33,6 °C
Q = 202 J
The formula is: Q = c * m * ([tex]t_{2} - t_{1}[/tex])
c = [tex]\frac{Q}{m * (t_{2} - t_{1} )}[/tex]
Calculating:
c = 202 J / 0,044 kg * (33,6 °C - 22 °C) ≈ 395,8 J/(kg * °C)
One mole (mol) of nitrogen monoxide (NO) has a mass of 30.01 g. When
precisely 2 moles of NO(g) are produced in the following chemical reaction, 43
kcal of heat energy is "absorbed."
N2(g) + O2(g) → 2 NO(g), AH = +43 kcal
How much heat (in kJ) is exchanged when 152 g of NO(g) is produced?
Answer:
455.6 kJ.
Explanation:
Hello there!
In this case, according to the given reaction, we know that 2 moles of NO require 43 kcal of energy, thus, for the energy required by 150 g of NO we first need the moles, considering its molar mass (30.01 g/mol):
[tex]152g*\frac{1mol}{30.01g} =5.065mol[/tex]
Thus, we apply the following dimensional analysis to obtain the energy absorbed by 5.065 moles:
[tex]5.065mol*\frac{43kcal}{2mol} =108.9kcal[/tex]
Which kJ turns out:
[tex]108.9kcal*\frac{4.184kJ}{1kcal}\\\\455.6kJ[/tex]
Best regards!
In order to be in a position to manipulate any operation, one has to know all the fine details of the system and where and how one might apply subtle changes to affect the outcome. When looking at chemical reactions, it is from the study of its kinetics that one gleams the insight necessary to be able to do this. The main use of chemical kinetics is to measure the speed of a chemical reaction. But more importantly, in measuring the speed of a reaction, one gains insight as to what part of the reaction imparts this speed (or lack thereof) and thus allows one to propose a specific mechanism that details the critical pathway for the reaction. Measuring the speed of a chemical reaction is very similar to measuring speed in general, except that instead of talking in terms of distance traveled per unit time we are measuring either reactants consumed per unit time or products produced per unit time. There are many factors that affect the speed of a chemical reaction, some of the more common ones being:
Answer:
See explanation
Explanation:
Chemical kinetics, the branch of physical chemistry that is concerned with understanding how fast or how slow chemical reactions occur (Encyclopedia Britannica).
The study of the kinetics of a chemical reaction is helpful in many ways. Most important is the fact that it allows one to propose a specific mechanism that details the critical pathway for the reaction.
The factors that affect the rate of chemical reaction includes; concentration of reactants, temperature, nature of reactants , the solvent used, the presence of a catalyst, presence of light, surface area of reactants and pressure for gaseous reactants.
How does the average reaction rate differ from an instantaneous reaction rate?
a) The average reaction rate is how quickly the reaction proceeds at a specific time. An instantaneous reaction rate is how quickly the reaction proceeds over time.
b) The average reaction rate is how quickly the reaction proceeds over time considering the reactants. An instantaneous reaction rate is how quickly the reaction proceeds at a specific time considering the products.
c) The average reaction rate is how quickly the reaction proceeds over time. An instantaneous reaction rate is how quickly the reaction proceeds at a specific time.
d) The average reaction rate is how quickly the reaction proceeds over time. An instantaneous reaction rate is how quickly the reaction proceeds compared to another reaction.
Answer:
The average reaction rate is how quickly the reaction proceeds at a specific time. An instantaneous reaction rate is how quickly the reaction proceeds over time.
Explanation:
Which word best describes gamma rays?
A)Weak
B)Destructive
C)Visible
D)Harmless
Answer:
Explanation:
Destructive :D
According to the position of gamma rays in electromagnetic spectrum,the word which best describes gamma rays is destructive as they have high energy.
What is electromagnetic spectrum?The electromagnetic spectrum consists of electromagnetic radiation which consists of waves made up of electromagnetic field which are capable of propogating through space and carry the radiant electromagnetic energy.
The radiation are composed of electromagnetic waves which are synchronized oscillations of electric and magnetic fields . They are created due to change which is periodic in electric as well as magnetic fields.
In vacuum ,all the electromagnetic waves travel at the same speed that is with the speed of air.The position of an electromagnetic wave in an electromagnetic spectrum is characterized by it's frequency or wavelength.They are emitted by electrically charged particles which undergo acceleration and subsequently interact with other charged particles.
Learn more about electromagnetic spectrum,here:
https://brainly.com/question/23727978
#SPJ6
Which weather event usually occurs when a cold front moves into an area?
O A. mild weather, because cold air pushes warmer air to the side
O
B. mild weather, because cold air pushes warmer air up
C. a storm, because cold air pushes warmer air up
O D. a storm, because cold air pushes warmer air to the side
Question 6 of 10
Which law of motion states that an object's acceleration is directly related to
the net force applied and inversely related to the mass of the object?
O A. Newton's law of inertia
O B. Newton's second law
Ο Ο Ο
C. Newton's third law
OD. Newton's first law
Which element has a larger atomic size? Nitrogen or phosphorus, explain how you know.
Explanation:
The elements nitrogen and phosphorus are in the same Group 15 with nitrogen being higher, so for the neutral atoms, N with its outer electrons in the n = 2 level would have a smaller radius than P with its outer electrons in the n = 3 level. ... (a) N3- has the largest radius.
On the periodic table, nitrogen and phosphorus can both be found in group 15, with nitrogen in period two and phosphorous in period three. This indicates that phosphorus has more electron shells occupied than nitrogen. Thus, nitrogen's atomic size will be lowered.
What is atomic size ?A chemical element's atomic radius, which is typically the average or typical distance between the nucleus's core and the outermost isolated electron, serves as a gauge for the size of an atom. Considering that the boundary is not a clearly defined physical object.
Atomic radii in the periodic table decrease across a row from left to right and increase across a column from top to bottom. Due to these two patterns, the periodic table's lower left and upper right corners, respectively, contain the largest and smallest atoms.
The size of the atom or ion is determined by the size of the largest filled orbital because electrons are what occupy space in atoms.
Thus, nitrogen's atomic size will be lowered.
To learn more about atomic size, follow the link;
https://brainly.com/question/1127028
#SPJ5
Given that a 0.130 M HCl(aq) solution costs $39.95 for 500 mL, and that KCl costs $10/ton, which analysis procedure is more cost-effective
Answer:
KCl is cost effective
Explanation:
In order to know this, we need to see how much it cost 1 g of each reactant. Let's begin with HCl
HCl:
In this case, let's calculate the moles of HCl in a 0.130 M solution and then, the mass of HCl using the molecular weight of 36.5 g/mol, to get the cost the HCl at the end using the given price:
nHCl = 0.130 moles/L * 0.5 L = 0.065 moles
mHCl = 0.065 moles * 36.5 g/mol = 2.3725 g
Cost HCl = 39.95 $ / 2.3725 g = 16.84 $/g
Conclusion, 1 g of HCl costs 16.84 $
KCl:
In this case, it's pretty obvious that 1 ton of KCl cost 10$, so, there is no need to do further calculations because 1 ton (or more than 1000 kg of the salt) it's just 10$. This is less expensive than the 16.84$ for just 1 g of HCl, so, final conclusion, KCl is more cost-effective.
Hope this helps
Look at the potential energy diagram below. What amount of energy does the products have ?
100
80
PE
50
AB
40
C D
20
Progress of the reaction
40 KJ
60 KJ
O 20 KJ
80 KJ
Answer:
20 kJ
Explanation:
The products are C + D which is on the right side of the diagram. And it says it has 20 kJ of energy.
How many significant figures
are in this number?
3 x 10^6
A chemical equation is balanced when the number of each
type of ____ is the same on both sides of the equation.
Answer:
element
Explanation:
HELP! URGENT Which of the following best states the relationship between erosion and deposition?
A.
When the energy transporting sediments diminishes, the sediments settle in a low-lying area; therefore, deposition always follows erosion.
B.
When the energy transporting sediments diminishes, the sediments settle in a low-lying area; therefore, erosion always follows deposition.
C.
When rock is broken down into sediments, the sediments are eventually transported to another location; therefore, deposition is a form of erosion.
D.
When rock is broken down into sediments, the sediments are eventually transported to another location; therefore, erosion is a form of deposition.
In a reaction involving the iodination of acetone, the following volumes were used to make up the reaction mixture: 5 mL 4.0M acetone 5 mL 1.0 M HCl 5 mL 0.0050 M I2 10 mL H2O While keeping the total volume at 25 mL and keeping the concentration of H ion and I2 as in the original mixture, how could you double the molarity of the acetone in the reaction mixture
Answer:
Explanation:
pls give me point so i can ask questions
4 points 15. The diagram below shows the relative positions of Earth, the moon, and the sun. The moon is shown at four possible positions around Earth. 3 Sunlight Sun Earth mo Which position of the moon could result in a lunar eclipse? В. 2 A B
Answer:
b c
Explanation:
Answer: b c
Explanation: i did test
Determine the energy change in the following reaction. This reaction is considered ...
C6H12 + O2
CO2 + H2O + heat
energy absorbed is equal to the energy released
endothermic
O isothermic
O exothermic
Answer:isothermic
Explanation:
Answer:
Energy abosorbed = Energy released.
Thus ISOTHERMIC
A student burned her magnesium sample according to the procedure and obtained a light gray product. Since the crucible looked dirty anyway, she skipped the steps to convert the Mg3N2 contamination to MgO, weighed the gray sample, and calculated the mass of her product. Was her resulting mass likely to be higher or lower the expected
Answer:
The resulting mass will be higher than expected
Explanation:
We have to keep this in mind; When magnesium is being burnt in air, two reactions are taking place. The first one is;
2Mg(s) + O2(g) ------> MgO(s) -------1
And
3Mg(s) + N2(g) -------> Mg3N2(s) ---------2
Now, if the steps that should be taken to convert Mg3N2 to MgO are not taken, the reaction is much quicker but a higher mass of solid is obtained than what was expected.
This higher mass of solid obtained owes to the fact that Mg3N2 from reaction 2 was not converted to MgO leading to contamination of the product.
Rotation about C-C single bonds allows a compound to adopt a variety of _____________. conformations configurations formations isomers projections are often used to draw the various conformations of a compound. conformations are lower in energy, while conformations are higher in energy. The difference in energy between staggered and eclipsed conformations of ethane is referred to as strain. strain occurs in cycloalkanes when bond angles deviate from the preferred °. The conformation of cyclohexane has no torsional strain and very little angle strain. The term "ring flip" is used to describe the conversion of one conformation into the other. When a ring has one substituent the equilibrium will favor the chair conformation with the substituent in the position.
Answer:
Conformation
Explanation:
Conformation refers to "any of the spatial arrangements which the atoms in a molecule may adopt and freely convert between, especially by rotation about individual single bonds"(Oxford dictionary).
Carbon-Carbon single bonds are known to undergo rotations about its axis. These rotations leads to various conformations. The energy difference between conformations may be low or high depending on the structure of the molecule. The difference in energy between conformations determines a molecules's preferred conformation.
Which would be another way to make the ice melt faster
Answer:
d because ur heating the ice and causing friction
Add one or more curved arrows to show the movement of electrons in the reaction. To draw the arrows, select More in the drawing menu, then select the appropriate curved arrow. Click on a bond or electron to start a curved arrow. Do not start from an atom. Use the select tool to move the arrow head and tail to the desired placement. When the curved arrow changes from red to black, your arrow has an appropriate starting and ending point. Draw curved arrows. Select Draw Rings More Erase С 0 heat -=-=- H3C—0. +.0—CH HCO CH, 2
Answer:
H3C - O - O - CH -HCOCH2.
Explanation:
Before chemical reaction can occur, some steps has to be followed in order to give the final product (s), this steps can be shown by drawing the chemical compound and showing how bonds are being broken or formed. Showing this in a stepwise manner is known as reaction mechanism.
From the question above, it is given that the products after heating the reactant gives H3C—0. +.0—CH HCO CH2.
The starting material can be deduce as;
H3C - O - O - CH -HCOCH2.
Heat causes something to divide or melt. Kindly check the attached picture which shows how the deduced starting compound splits to give H3C—0. and .0—CH HCO CH2.
Based on your understanding of color's relationship to wavelength, identify the approximate wavelength of light (nm) emitted by strontium when it was burned in Part C. (No quantitative data was collected for this; you are giving an approximate value only, based on what you observed.) Explain your reasoning in full, making sure to cite specific data and observations to support your answer.
Answer:
The flame colour of strontium is red. Red has a wavelength of around 620 to 750 nm.
Explanation:
Visible light is part of the electromagnetic spectrum. The electromagnetic waves are composed of electric and magnetic fields.
The visible spectrum is composed of seven different wavelengths that corresponds to different colours. When a metallic element is exposed flame, one of these colours is observed. This is commonly called the flame test.
The flame colour of strontium is red. Red has a wavelength of around 620 to 750 nm.
The approximate wavelength of light (nm) emitted by strontium when it was burned is red, where red has a wavelength of round 620-750 nm.
Wavelength of light emitted by strontiumGenerally, Visible mild is phase of the electromagnetic spectrum. the electromagnetic waves are composed of electric powered and magnetic fields. When a metal factor is uncovered flame, one of they seven colors of visible spectrum is seen.
The flame shade of strontium is red, where red has a wavelength of round 620-750 nm.
For more information on Wave
https://brainly.com/question/3004869
If 27.37ml of 0.2115M NaOH is able to neutralize 37.45 of HCl, what is the concentration of the acid?
You just gotta match the moles:
moles of NaOH = 0.02737 L * 0.2115 M = 0.005789 mol of NaOH. The amount of moles of HCl it can neutralize should be the same since they are in a 1:1 ratio. Therefore, you can do moles of NaOH divided by 0.003745L to get the answer. It turns out to be 0.1546M.
Aqueous hydrochloric acid will react with solid sodium hydroxide to produce aqueous sodium chloride and liquid water . Suppose 14. g of hydrochloric acid is mixed with 6.55 g of sodium hydroxide. Calculate the minimum mass of hydrochloric acid that could be left over by the chemical reaction. Round your answer to significant digits.
Answer:
8.02 g of HCl could be left over by the chemical reaction
Explanation:
We propose the reaction:
HCl(aq) + NaOH (s) → NaCl (aq) + H₂O (l)
Ratio is 1:1. First of all, we determine the moles of reactants:
14 g . 1mol / 36.45g = 0.384 mol of acid
6.55 g. 1mol / 40g = 0.164 mol of base
If a determined mass of HCl, could be left; this means that the acid is the excess reagent.
For 0.164 moles of NaOH, we need 0.164 moles of HCl.
As we have 0.384 moles, (0.384 - 0.164) = 0.220 moles of acid are left over in the reaction. We convert the moles to mass:
0.220 mol . 36.45 g /1mol = 8.02 g
assume that the density of all solutions are 1.000g/ml 1. Calculate the molarity of calcium in 1.9g of calcium chloride diluted in 100 ml of Di water. 2 Calculate the concentration of both calcium and chloride lons in problem 1 in units of mg/mL, ug/L, mg/L and ug/mL. 3. Calculate the concentration of both calcium and chloride ion in problem 1 in units of ppm and ppb. You may assume that the density of the solution is 1.0 g/ml 4. You have been provided 100 ml of a 1000 ug/ml barium standard. What volume of this standard must be diluted to a final volume of 50 ml using DI water to produce a 30 ug/mL standard
Answer:
1. 0.1712M
2. 6.86mg/mL Ca, 12.14mg/mL Cl, 6860000ug/L Ca, 12140000ug/L Cl, 6860mg/L Ca, 12140mg/L Cl, 6860ug/mL Ca, 12140ug/mL Cl.
3. 6860ppm Ca and 12140ppm of Cl.
4. 1.5mL of the 1000ug/mL barium standatd must be taken.
Explanation:
1. Molarity is defined as the amount of moles of solute (Calcium chloride) present in 1L of solution.
The moles of CaCl₂ are:
1.9g CaCl₂ * (1mol / 110.98g) = 0.01712 moles
In 100mL = 0.10L:
0.01712mol / 0.10L = 0.1712M
2. The masses of Calcium and Chloride ions are:
1.9g * (40.078g Ca / 110.98g) = 0.686g Ca
And:
1.9g - 0.686g Ca = 1.214g Cl
mg/mL:
686mg Ca / 100mL = 6.86mg/mL Ca
1214mg Cl / 100mL = 12.14mg/mL Cl
ug/L:
686000ug / 0.1L = 6860000ug/L Ca
1214000ug/ 0.1L = 12140000ug/L Cl
mg/L:
686mg Ca / 0.1L = 6860mg/L Ca
1214mg Cl / 0.1L = 12140mg/L Cl
ug/mL:
686000ug Ca / 100mL = 6860ug/mL Ca
1214000ug Cl / 100mL = 12140ug/mL Cl
3. ppm are defined as mg/L, the ppm of Ca are 6860ppm Ca and 12140ppm of Cl
4. The solution must be diluted from 1000ug/mL to 30ug/mL, that is a dilution of:
1000ug/mL / 30ug/mL:
33.33 times must be diluted the solution.
As final volume of the diluted solution must be 50mL, the volume of the standard needed is:
50mL / 33.33 times = 1.5mL of the 1000ug/mL barium standatd must be taken
Name this molecule c4h7bro
Answer:
I believe its : "2-Bromobutanal"
Hard water often contains dissolved Ca^2+ and Mg^2+ ions. One way to soften water is to add phosphates. The phosphate ion forms insoluble precipitates with calcium and magnesium ions, removing them from solution. A solution is 0.055 MM in calcium chloride and 0.075 MM in magnesium nitrate. What mass of sodium phosphate would you add to 1.0 LL of this solution to completely eliminate the hard water ions? Assume complete reaction.
Answer:
14.2g of sodium phosphate are required
Explanation:
To solve this question we need to find the moles of Ca²⁺ and Mg²⁺ ions. And based on the reactions:
3Ca²⁺ + 2PO₄³⁻ → Ca₃(PO₄)₂ (s)
3Mg²⁺ + 2PO₄³⁻ → Mg₃(PO₄)₂ (s)
we can find the moles of phosphate required to precipitate all these ions and its mass:
Moles Ca²⁺:
1.0L * (0.055mol / L) = 0.055mol
Moles Mg²⁺:
1.0L * (0.075mol / L) = 0.075mol
Total moles = 0.13 moles of ions
Moles of phosphate ion required:
0.13 moles * (2 moles PO₄³⁻ / 3 moles ions) = 0.0867 moles PO₄³⁻
The moles of sodium phosphate (Na₃PO₄) are = 0.0867 moles
The mass is -Molar mass Na₃PO₄: 164g/mol-:
0.0867 moles Na₃PO₄ * (164g / mol) =
14.2g of sodium phosphate are requiredPls help I’ll mark brainliest
Answer: I will answer if u Mark me
Explanation:
what causes deep ocean currents to flow
Answer:Deep ocean currents (also known as Thermohaline Circulation) are caused by: ... The sinking and transport of large masses of cool water gives rise to the thermohaline circulation, which is driven by density gradients due to variations in temperature and salinity. The earth's rotation also influences deep ocean currents.
Explanation:
Which statement is true about the speed of light? (2 points)
Light travels relatively slowly.
Distance in space is measured using the speed of light.
Time in space is measured using the speed of light.
The speed of light is unknown
Answer:
2nd option is the correct answer of this question
Answer:
yes it is b
Explanation: