Answer:
37.09 g of B₅H₉ is required to form 148 g of borate salt( Na₂B₄O₇ )
Explanation:
Given the data in the question;
B₅H₉ → H₃BO₃ → Na₂B₄O₇
find the mass (in grams) of B5H9 required to form 148 g of the borate salt by this reaction sequence.
S M.W
B₅H₉ 63
H₃BO₃ 62
Na₂B₄O₇ 201
So, moles of Na₂B₄O₇ = 148 / 201 = 0.736
Since Boron will be conserved,
Moles of Boron atoms in Na₂B₄O₇ will be;
⇒ 4 × 0.736 = 2.944
Now, Moles of Boron in Na₂B₄O₇ = Moles of Boron in H₃BO₃ = Moles of Boron in B₅H₉
Hence,
Moles of Boron in B₅H₉ = 2.944
Moles of B₅H₉ = 2.944 / 5 = 0.5888
Mass of B₅H₉ = 0.5888 × 63 = 37.09 g
Therefore, 37.09 g of B₅H₉ is required to form 148 g of borate salt( Na₂B₄O₇ )
How many molecules are contained in 52.5 moles of C2H6?
please explain if you can
Answer:
3.16x10²⁵ molecules
Explanation:
1 mol refers to the amount of a substance. The amount of C₂H₆ molecules (or any other substance) that are in one mol is given by Avogadro's number:
1 mol contains 6.023x10²³ particles (be it atoms, molecules or ions).With that in mind we can calculate how many molecules are there in 52.5 moles:
52.5 mol * 6.023x10²³ molecules/mol = 3.16x10²⁵ moleculesWhat is the molar mass of H2SO4?
(Molar mass of H = 1.0079 g/mol; S = 32.065 g/mol; O = 15.999 g/mol)
Answer: 98.08 g/mol
Explanation:
i just took this test and got it right
Answer:
A
Explanation:
grams of sodium 9.5g in NaCl
Answer:
3.68 grams.
Explanation:
First we convert 9.5 g of NaCl into moles of NaCl, using its molar mass:
9.5 g ÷ 58.44 g/mol = 0.16 mol NaCl
In 0.16 moles of NaCl there are 0.16 moles of sodium as well.
We now convert 0.16 moles of sodium into grams, using sodium's molar mass:
0.16 mol * 23 g/mol = 3.68 g
A compound composed of only nitrogen and iodine is found to contain 3.55% nitrogen by mass. Its empirical and molecular formulas are the same. What is the hybridization of the nitrogen atom in this compound?
Answer:
The nitrogen atom is sp³ hybridized
This is trigonal pyrymid shape
Explanation:
Step 1: Data given
A compound contains only nitroen (N) and Iodine (I)
The procent of nitrogen by mass = 3.55%
Atomic mass of N = 14.0 g/mol
Atomic mass of I = 126.9 g/mol
Step 2: Calculate mass % of iodine
Mass % iodine = 100 % - 3.55%
Mass % iodine = 96.45 %
Step 3: Calculate number of moles
Let's suppose the total mass = 100 grams
Mass of N = 3.55 grams
Mass of I = 96.45 grams
Moles N = 3.55 grams / 14.0 g/mol = 0.254 moles
Moles I = 96.45 grams / 126.9 g/mol = 0.760 moles
Step 4: Calculate empirical formula
For 0.254 moles N we have 0.760 moles I this is 1:3
This means that for 1 mol N we have 3 moles I
The empirical ( and also the molecular) formula is I3N
The nitrogen atom is sp³ hybridized.
This is trigonal pyrymid shape
Which statements correctly describe the relationship between the event and its effect on energy inputs and outputs?
A. The eruption of a volcano increases the concentration of particles in the atmosphere, which decreases the amount of energy that can reach Earth from the Sun in the short term.
B. Burning fossil fuels decreases the concentration of greenhouse gases in the atmosphere, which decreases the amount of heat that reflects back to Earth's surface.
C. Changes in Earth's orbit periodically increase the amount of solar energy reaching Earth from the Sun, which raises temperatures.
Answer:
They Are All Very Good Statements But I Will Go With "A"
Explanation:
I go with "A" Because In The statement it has a cause an effect, it has a positive term and a negative term, in other uses it is "A" between energy inputs and outputs, and events.
The statement that correctly describes the relationship between the event and its effect on energy inputs and outputs is Option A .
What is Energy ?Energy is defined as the capacity to do work .
There are various types of Energy , Light Energy , Sound Energy , Solar Energy , Wind Energy etc .
Volcanic eruptions emit huge amounts of volcanic dust, sulfur compounds and water vapor into the atmosphere .
This reduces the atmospheric transparency and that results into causing hindrance to the solar radiation penetration in the earth's surface ,
This results in short term cooling effect over large areas of earth.
Among all the statements , Option A , The eruption of a volcano increases the concentration of particles in the atmosphere, which decreases the amount of energy that can reach Earth from the Sun in the short term , correctly describe the relationship between the event and its effect on energy inputs and outputs.
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Score! You manage to find a bottle of bromothymol blue and a few extra beakers. You take one of the empty beakers and add some of the first unlabeled solution and some indicator. The color changes to yellow. You then add some solution from the other unlabeled flask into this beaker and see the color change to blue. What are the identities of each unlabeled solution
Answer:
You manage to find a bottle of bromothymol blue and a few extra beakers. You take one of the empty beakers and add some of the first unlabeled solution and some indicator.
The color changes to yellow.
You then add some solution from the other unlabeled flask into this beaker and see the color change to blue.
What are the identities of each unlabeled solution?
Explanation:
Bromothymol blue is a dye and it is used as an indicator.
It is used as a pH indicator.
In acids, it becomes yellow n in color.
In bases, it turns blue.
You take one of the empty beakers and add some of the first unlabeled solution and some indicator. The color changes to yellow.
That means the unlabeled solution is an acid.
You then add some solution from the other unlabeled flask into this beaker and see the color change to blue.
It is a basic solution.
9) Determine the end (final) value of n in a hydrogen atom transition, if the electron starts in and the atom emits a photon of light with a wavelength of 486 nm.
Define electronegativity
Answer: Electronegativity is a measure of the tendency of an atom to attract a bonding pair of electrons.
Explanation: Hope this helps!
A student was given the task of titrating a 20.mL sample of 0.10MHCl(aq) with 0.10MNaOH(aq). The HCl(aq) was placed in an Erlenmeyer flask. An equation for the reaction that occurs during the titration is given above. (a) According to the equation for the reaction, if the amount of the reactants is halved, how does this affect the amount of H2O(l) produced in the reaction
Answer:
The amount H2O produced is also halved
Explanation:
A strong acid as HCl reacts with a strong base as NaOH producing water and a salt, NaCl. The reaction is:
HCl + NaOH → NaCl + H₂O
Where 1 mole of HCl reacts per mole of NaOH to produce 1 mole of water.
That means, if the amount of HCl and NaOH is halved, the amount H2O produced is also halved because 1 mole of each reactant produce 1 mole of water
Give the corresponding electron configurations for following element atoms, their valence electrons, and their ions, respectively.
a. P
b. Sa
c. Ni
d. Br
e. O
Answer:
Explanation:
Element Electron configuration Valence electron Ion
for atom configuration
P 1s²2s²2p⁶3s²3p³ 3s²3p³ P⁵⁺
Sn 1s²2s²2p⁶3s²3p⁶4s²
3d¹⁰4p⁶4d¹⁰5s²5p² 5s²5p² Sn⁴⁺
Ni 1s²2s²2p⁶3s²3p⁶4s² 4s²3d⁸ Ni²⁺
3d⁸
Br 1s²2s²2p⁶3s²3p⁶4s² 4s²4d⁵ Br⁻
3d¹⁰4p⁵
O 1s²2s²2p⁴ 2s²2p⁶ O²⁻
An atom's electron configuration is a depiction of the distribution of electrons amongst the orbital shells as well as subshells. The electron configuration is frequently used to define an atom's orbitals in its ground state, but it may also be used to depict an atom which has ionized into a negatively charged ion or positively charge ion by accounting for electron loss or gain in succeeding orbitals. Many of an element's physical and chemical features can be linked to its distinct electron configuration. The distinctive chemistry of the element is determined by the valence electrons, which are electrons in the outermost shell.
Draw the structure of the starting material needed to make 2‑methylhept‑3‑yne (or 2‑methyl‑3‑heptyne) using sodium amide in liquid ammonia, followed by 1‑bromopropane.
Answer:
See explanation and image attached
Explanation:
2‑methylhept‑3‑yne can be made by the reaction of the compound shown in the image attached with soidamide in liquid ammonia and 1‑bromopropane.
The first step in the reaction is the deprotonation of the alkyne starting material by the amide ion.
This step is followed a nucleophilic substitution reaction of the alkyne with 1‑bromopropane to yield the 2‑methylhept‑3‑yne product.
Determine the total kilojoules in two tablespoons of crunchy peanut butter that contains 2 g of carbohydrate, 15 g of fat, and 9 g of protein.
Answer:
The correct answer is -749.437 Kilojoules
Explanation:
In the case of nutrition, Kcal and cal are equal and each macromolecule produces a specific amount of energy in terms of calories. Carbohydrates and protein generate 4 kcal whereas fat generates 9 kcal per gram.
1 g of carbohydrate = 4 kcal
so, 2 gram of carbohydrate = 8 kcal
9 g of protein = 9*4
= 36 kcal
15 g of fat = 15*9
= 135 kcal
in total = 135 + 36 + 8 kcal
= 179 kcal
and, one kcal = 4.186798 kJ
so 179 kcal = 4.186798 * 179
= 749.437 Kilojoules
(vi) A solvent extraction in which two ...... liquids move in opposite directions in
continuous contact with each other.
(a) immiscible (b) miscible (c) polar
(d) non-polar
Answer:
(A). Immmiscible
Liquid/Liquid extraction is a solvent extraction in which two immiscible liquids move in opposite directions are in continuous contact with each other.
Explanation:
A liquid/liquid extraction is a method used to separate mixtures based on relative solubilities in two immiscible liquids, i.e., liquids that do not dissolve in each other but rather form separate layers when placed in the same glassware.
The immiscibility of the liquids is as a result of the two liquids having different polarities. One liquid is polar while the other is non polar, usually water which is polar and an organic solvent which is non-polar. The most common pair of extraction solvents used is diethyl ether or simply ether and water. They separate into layers and the position most each solvent in either the bottom or top layer is determined by its density. Ether is always found on the top layer while water is found innthe bottom layer because ether is less than than water. The density of ether is 0.713 g/cm3 and the density of H2O is 1.0 g/cm3.
The compound to be extracted dissolves into either of the layers based on the principle that like dissolves like. Polar compounds will dissolve into the water layer while organic nor non-polar compounds will dissolve in the ether layer. The compound is the extracted from either of the layer it is dissolved in.
Which functional group identifies a compound as an alcohol
Answer:
-OH functional group
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A 0.2264 g sample of a pure carbonate, XnCO3(s) , was dissolved in 50.0 mL of 0.1800 M HCl(aq) . The excess HCl(aq) was back titrated with 24.90 mL of 0.0980 M NaOH(aq) . How many moles of HCl react with the carbonate
Answer:
6.56x10⁻³ mol
Explanation:
First we calculate how many HCl moles are there in 50.0 mL of a 0.1800 M solution:
0.1800 M * 50.0 mL = 9.00 mmol HClThen we need to calculate how many HCl moles were in excess, that number is the same as the number of NaOH moles they reacted with:
0.0980 M * 24.90 mL = 2.44 mmol NaOH = 2.44 mmol HClFinally we calculate the difference between the original number of HCl moles and the number remaining after the reaction with XnCO₃:
9.00 mmol - 2.44 mmol = 6.56 mmol6.56 mmol / 1000 = 6.56x10⁻³ molHelppppp
What is the mass of 4.09 x 10^22 molecules of oxygen gas?
1.09 grams
7.69 x 1044 grams
2.17 grams
0.0679 gram
Answer:
[tex]2.17gO_2[/tex]
Explanation:
Hello there!
In this case, according to the given information, it turns out possible for us to calculate the mass of 4.09 x 10^22 molecules of oxygen gas by firstly keeping in mind that that 1 mole of it has a mass of 32.0 g and secondly that 1 mole of any substance contains 6.022x10^23 representative units, in this case, molecules of O2, and thus, the appropriate setup to perform this conversion is shown below:
[tex]4.09x10^{22}molecules \ O_2*\frac{1molO_2}{6.022x10^{23}molecules \ O_2}*\frac{32.0gO_2}{1molO_2} \\\\2.17gO_2[/tex]
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help pls I'll give you briliantest by tomorrow 11:59pm pls no links
Answer:
It's sunset because the sun sets in the west and rises in the east. The shadow is going west therefore the sun must be in the east. Also the shadow is super long meaning the sun has to be close to the horizon.
Explanation:
Which of the following statements is NOT true?
A.) When HX adds to an asymetrical alkene, the SP2 carbon bonded to the most H atoms is protonated.
B.) When HX adds to an asymetrical alkene, protonation leads to the most stable carbocation intermediate.
C.) When HX adds to a symetrical alkene, either of the SP2 carbons can be protonated.
D.) When HX adds to an asymetrical alkene, the halogen attaches to the least substituted SP2 carbon.
Answer:
D.) When HX adds to an asymmetrical alkene, the halogen attaches to the least substituted sp² carbon.
Explanation:
Which of the following statements is NOT true?
A.) When HX adds to an asymmetrical alkene, the sp² carbon bonded to the most H atoms is protonated. TRUE. This is known as Markovnikov's rule.
B.) When HX adds to an asymmetrical alkene, protonation leads to the most stable carbocation intermediate. TRUE. The order of stability of carbocations is tertiary > secondary > primary.
C.) When HX adds to a symmetrical alkene, either of the sp² carbons can be protonated. TRUE. Since the alkene is symmetrical, either carbon can be protonated.
D.) When HX adds to an asymmetrical alkene, the halogen attaches to the least substituted sp² carbon. FALSE. The halogen attaches to the most substituted sp² carbon.
If I contain 3 moles of gas in a container with a volume of 60 liters and at a temperature of 400 K, what is the pressure inside the container in mmHg?
Answer:
n = 3.0 moles
V = 60.0 L
T = 400 K
From PV = nRT, you can find P
P = nRT/V = (3.0 mol)(0.0821 L-atm/K-mol)(400 K)/60.0L
P = 1.642 atm = 1.6 atm (to 2 significant figures)
Explanation:
2. (05.02 MC)
What is the mass of a sample of NHz containing 7.20 x 1024 molecules of NH3? (5 points)
161 grams
187 grams
203 grams
214 grams
HELPPPPPP
Solution :
We know, molecular mass of NH₃ is , M = 17 g/mol .
Number of moles of NH₃ in 7.2 × 10²⁴ are :
[tex]n = \dfrac{7.2 \times 10^{24}}{6.022 \times 10^{23}}\\\\n = 11.96\ moles[/tex]
So, mass of NH₃ present in 11.96 moles is :
m = 11.96 × 17 gram
m = 203.32 gram
Hence, this is the required solution.
1. What is Mars ? Explain your answer.
What is Earth ? Explain your answer.
.
Mars is the fourth planet.
Earth is the third planet.
Both revolve around the Sun.
Both are rocky planets.
Earth is habitable for carbon based life forms.
Mars is not habitable for carbon based life forms.
What characteristic of a light wave in a medium determines the index of refraction of that
medium?
Answer:
The refractive index can be seen as the factor by which the speed and the wavelength of the radiation are reduced with respect to their vacuum values: the speed of light in a medium is v = c/n, and similarly the wavelength in that medium is λ = λ0/n, where λ0 is the wavelength of that light in vacuum.
Explanation:
Explain how our body systems work together to get oxygen into and around our body.
Answer: (1) Inhales (breathes in) Oxygen - good for the body - gives it to the Circulatory System to be transported throughout the body through the blood. (1) Digestive System gets nutrients (good) from food and hands it over to the blood and Circulatory System then carries those nutrients where they need to go.
PLEASE HELP NEED IT ASAP
A solution has a [H3O+] of 1 × 10−3 M. What is the [OH−] of the solution?
11 M
14 M
1 × 10−14 M
1 × 10−11 M
Answer:
1 × 10−11 M
Explanation:
I took the test :) guy above me is right
What's the purpose for a graduated cylinder
Answer:
Graduated cylinders are long, slender vessels used for measuring the volumes of liquids. They are not intended for mixing, stirring, heating, or weighing. Graduated cylinders commonly range in size from 5 mL to 500 mL.
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A solution of carbonic acid is at equilibrium. How would the system change is more carbonic acid was added to the solution
Answer:
The equilibrium position shifts to the right, in accordance to the constraint principle
How do you determine the mass number of an atom?
Explanation:
The number of protons and neutrons. you can simply subtract the number of protons, or atomic number, from the mass number to get your final answer.
You have a container of 5L with a Molarity of 0.750. What would be the new volume if you diluted the solution to have a concentration of 9.71M?
Answer:
=64.73..
Explanation:
0.750=5L
9.71=x
0.750*x÷0.750=5L*9.71÷0.750
x=48.55÷0.750
x=64.73..
I first want you to tell me why having a homogenous sample is good but also why it is bad. That is, what are the advantages and disadvantages to having a homogenous sample
Answer:
Following are the responses to the given question:
Explanation:
In many analyses, the homogenous sample with only a particular identity group is desired. Units were picked here depending on their similar characteristics so because research is specifically interested in these qualities. The downside of a homogeneous sample is nevertheless that the exterior validity of a study is decreased. In other words, any results obtained could be appropriately widespread to the general population. On either hand, a heterogeneous sample is capable of overcoming this difficulty, because its diversity is the typical pattern of any sort of sample distortion inside the broader population.
what temperature is absolute zero