Answer:
B. Alleles
Explanation:
ection
9)
A compound consists of 25.9% nitrogen and 74.1% oxygen by mass. What is the empirical
formula of the compound?
A)
NOZ
B)
NO
C)
N₂Os
D)
0
1
N20
2
3
4
5
6
7
8
9
0
21
2
Answer:
69
Explanation:
If there is sufficient water in the reaction system, how many grams of KOH can be produced from 22.2 g of K?
Answer: 31.9 g of KOH can be produced from 22.2 g of KOH
Explanation:
To calculate the moles :
[tex]\text{Moles of solute}=\frac{\text{given mass}}{\text{Molar Mass}}[/tex]
[tex]\text{Moles of} K=\frac{22.2g}{39g/mol}=0.57moles[/tex]
[tex]2K+2H_2O\rightarrow 2KOH+H_2[/tex]
According to stoichiometry :
2 moles of [tex]K[/tex] produce = 2 moles of [tex]KOH[/tex]
Thus 0.57 moles of [tex]K[/tex] will produce=[tex]\frac{2}{2}\times 0.57=0.57moles[/tex] of [tex]KOH[/tex]
Mass of [tex]KOH=moles\times {\text {Molar mass}}=0.57moles\times 56g/mol=31.9g[/tex]
Thus 31.9 g of KOH can be produced from 22.2 g of KOH
You want to produce a casting of sterling silver that is silver plus 13 atomic% copper. Pure silver is too soft for many applications and adding 13 atomic% copper strengthens the silver without significantly changing the color. To produce the sterling silver casting, you are going to melt commercially available pure silver and copper in a furnace, and then you will pour the liquid metal mixture into a mold. The following questions relate to this alloy. (a) In selecting a furnace, what must be the minimum value of the high-temperature capability of your selected furnace
Answer:
1085° C
Explanation:
From the phase diagram of Ag-Cu shown below:
The minimum value of the high-temp required to be selected for the furnace is: 1085° C
This is on the grounds that the furnace should be chosen to such an extent that it should melt any sort of possible material including pure Cu that melts and liquefies at the temperature of 1085° C.
Two gases helium and x are released from one end of an evacuated long cylinder at the same time if it takes helium atoms 3 times faster than gas X to effuse from one end. What is gas X?
Answer:
Hypoflorous acid, HOF
Explanation:
From the question, we're told that the helium atoms effuses 3 times than the said gas X.
We can determine the rate of effusion by using the formula
r is inversely proportional to 1/√M, where M is the molecular mass of the gas.
And also,
r is inversely proportional to 1/t, where t is the time taken for effusion.
From both formulas I listed, we can conclude that t is directly proportional to √M. And thus we proceed.
The molecular mass of Helium is 4.
tHe = tX/3, where tx is the time taken for the unknown gas X
As of yet, we don't know the molecular mass of X. Next, we say that
tX/tHe =√Mx/MHe
3 = √Mx/4
If we square both the sides, to remove the square root, we have
9 = Mx/4
Mx = 36
The molecular mass of the unknown gas X is 36.
How many grams of iron contain 4.06X10^24 atoms of iron?
We have that the grams of iron contained 4.06X10^24 atoms of iron is
g= 376.6g
From the question we are told
How many grams of iron contain 4.06X10^24 atoms of iron?
Generally the equation for the Moles of Iron is mathematically given as
[tex]M=\frac{4.06x10^24}{6.02x10^23} \\\\M=6.744moles[/tex]
Therefore
Where Molar mass of Iron =55.845
Generally the equation for the mass is mathematically given as
g= 6.744 x 55.85
g= 376.6g
Therefore
the grams of iron contained 4.06X10^24 atoms of iron is
g= 376.6g
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What is the empirical formula for a compound that is 7.70 % carbon and 92.3 % chlorine?
Answer:
Imole/C=129 Directions Show All Of Your Work For Each Of The Following Problems. 1.
Explanation:
Which of the following combinations would form a buffer solution?
a. HF and Lif
b. NH3 and NH4Br
c. HNO2 and NaNO2
d. all of the above
e. none of the above
Answer:
d . all of the above
Explanation:
A buffer system can be formed in one of two ways:
A weak acid and its conjugate baseA weak base and its conjugate acidWhich of the following combinations would form a buffer solution?
a. HF and LiF. YES. HF is a weak acid and F⁻ (from LiF) is its conjugate base.
b. NH₃ and NH₄Br. YES. NH₃ is a weak base and NH₄⁺ (from NH₄Br) is its conjugate acid.
c. HNO₂ and NaNO₂. YES. HNO₂ is a weak acid and NO₂⁻ (from NaNO₂) is its conjugate base.
Is anyone good at chemistry if so can someone help me please ?
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In general, salts (formed during a neutralization reaction) are ionic compounds that are soluble in water and dissociate in solution into ions that conduct electricity. Out of the six statements given, there are three related statements that rehash the foregoing, and there are three related statements that are collectively incorrect.
Statements A, B, and D are (generally) true regarding salts formed during a neutralization reaction. When you consider that the net ionic equation of many acid-base neutralization reactions is H⁺(aq) + OH⁻(aq) → H₂O(l), the counterions of the H⁺(aq) and OH⁻(aq) are the aqueous spectator ions that comprise the salt. These ions are electrolytes, as they are charged species that can carry a current in solution; they are ionic compounds by definition since they're composed of cations and anions; and, as aqueous species, they're clearly dissolved in water.
Statements C, E, and F, as a whole, generally aren't true of such salts.
KNO3 ______ ions in an aqueous solution. A. Forms B. Does not form
Answer:
A
Explanation:
Calculate the pH of a solution prepared by dissolving 1.60 g of sodium acetate, CH3COONa, in 50.0 mL of 0.10 M acetic acid, CH3COOH(aq). Assume the volume change upon dissolving the sodium acetate is negligible. Ka of CH3COOH is 1.75 x 10^-5.
Answer:
pH = 5.35
Explanation:
Given 1.60 grams sodium acetate (NaOAc(aq))*** added to 50ml of 0.10M acetic acid (HOAc(aq)) solution.
Applying common ion effect keeping in mind that the addition of NaOAc provides the common-ion (OAc⁻).
HOAc(aq) ⇄ H⁺(aq) + OAc⁻(aq)
I 0.10m 1.32 x 10⁻³M ≈ ∅M* (1.6g/82.03g/mol) / 0.050L = 0.39M
C -x +x 0.39M + x ≈ 0.39M**
E 0.10M - x x 0.39M
≈ 0.10M
Ka = [H⁺][OAC⁻]/[HOAC] => [H⁺] = Ka·[HOAc] / [OAc⁻]
[H⁺] = (1.75 X 10⁻⁵)(0.10) / (0.39) = 4.5 x 10⁻⁶M
∴ pH = -log[H⁺] = -log(4.5 x 10⁻⁶) = -(-5.35) = 5.35
_______________________________________________
* [H⁺] before adding NaOAc = SqrRt(Ka · [HOAc]) = SqrRt(1.75 x 10⁻⁵· 0.10) = 1.32 x 10⁻³M. Since this concentration value is so small, the initial [H⁺] is assumed to be zero molar (∅M).
** The added [H⁺] is negligible and dropped in the ICE table. That is, adding ~[H⁺] in the order of 10⁻³M does not change the H⁺ ion concentration sufficiently to affect problem outcome and is therefore dropped in the ICE table.
*** Acetic Acid and Sodium Acetate are frequently written HOAc and NaOAc where the OAc⁻ anion is the acetate ion (CH₃COO⁻) for brevity.
The pH of the solution measures the acid of the liquid throughout the molar concentration of hydrogen ions in a solution.
[tex]\bold{CH_3COONa \ mass = 1.60\ g}\\\\[/tex]
Solution Volume (V) [tex]=50.0\ mL =0.05\ L\\\\[/tex]
[tex]\bold{CH3COONa \ molarity =0.10\ M }[/tex]
[tex]\bold{\text{Calculating the CH3COONa moles} =\frac{mass}{molar\ mass}}[/tex]
[tex]= \frac{1.60\ g}{82.03\frac{g}{mol}} \\\\=0.0195\ mol\\\\[/tex]
[tex]\bold{M = \frac{ \text{amount of solute moles} } { \text{solution volume in L} }}[/tex]
[tex]= \frac{0.0195\ mol}{0.05\ L}\\\\ =0.39\ M[/tex]
Using Henderson Hasselbach equation:
[tex]\bold{pH = -\log K_{a} + \log{[salt]}{[acid]}}\\\\[/tex]
[tex]=\bold{ -\log (1.75\times 10^{-5}) + \log ( \frac{0.39}{0.10}) }\\\\=\bold{ 4.757 + \log (3.9)}\\\\=\bold{ 4.757 + 0.5910}\\\\=\bold{ 5.348}\\\\=\bold{ 5.35}\\[/tex]
So, the final answer is "5.35".
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help please really need help
Answer:
2.14 × 10⁻³ molecules/RSP
3.31 × 10⁻³ molecules/ESP
Explanation:
Step 1: Calculate the number of moles of Acetaminophen per Regular Strength Pill (RSP)
A Regular Strength Pill has 1.29 × 10²¹ molecules of Acetaminophen per pill. To convert molecules to moles we will use Avogadro's number: there are 6.02 × 10²³ molecules in 1 mole of molecules.
1.29 × 10²¹ molecules/RSP × 1 mol/6.02 × 10²³ molecules = 2.14 × 10⁻³ molecules/RSP
Step 2: Calculate the number of moles of Acetaminophen per Extra Strength Pill (ESP)
An Extra Strength Pill has 1.99 × 10²¹ molecules of Acetaminophen per pill. To convert molecules to moles we will use Avogadro's number: there are 6.02 × 10²³ molecules in 1 mole of molecules.
1.99 × 10²¹ molecules/ESP × 1 mol/6.02 × 10²³ molecules = 3.31 × 10⁻³ molecules/ESP
What is the IUPAC name for the compound shown?
When 4.088 grams of a hydrocarbon, CxHy, were burned in a combustion analysis apparatus, 13.82 grams of CO2 and 2.829 grams of H2O were produced.
In a separate experiment, the molecular weight of the compound was found to be 78.11 amu. Determine the empirical formula and the molecular formula of the hydrocarbon.
Answer:
Empirical formula: CH
Molecular formula: C₆H₆
Explanation:
Based on the combustion of a hydrocarbon, the moles of CO₂ = Moles of Carbon in the hydrocarbon and the moles of H₂O = 1/2 moles of hydrogen in the hydrocarbon.
The empirical formula is the simplest whole number of atoms present in a molecule. With the moles of C and H we can find empirical formula:
Moles C -Molar mass CO₂ = 44.01g/mol-:
13.82g * (1mol / 44.01g) = 0.314 moles C
Moles H -Molar mass H₂O = 18.01g/mol-:
2.829g H₂O * (1mol / 18.01g) = 0.157 moles H₂O * (2mol H / 1mol H₂O) = 0.314 moles of H
The ratio of moles H: moles C:
0.314 moles / 0.314 moles = 1
That means empirical formula is:
CHWith the molecular weight and empirical formula we can find the molecular formula:
Molar mass CH = 12.01g/mol+1.01g/mol = 13.02g/mol
As the molecular weight of the molecule is 78.11amu = 78.11g/mol, there are:
78.11g/mol / 13.02g/mol = 6 times the empirical formula in the molecular formula
That means molecular formula is:
C₆H₆The body system responsible for breaking down food and absorbing nutrients is the ____
a
circulatory system
b
respiratory system
c
excretory system
d
digestive system
Answer:
d
digestive system
Explanation
chemical equation of sodium carbonate on hydrochloric acid
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Answer: Na2CO3 + 2 HCl → 2 NaCl + H2CO3
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what is acid by Lewis in science
A Lewis acid is a substance that accepts a pair of electrons to form a covalent bond. A Lewis base is a substance that donates a pair of electrons to form a covalent bond. So, a Lewis acid-base reaction is represented by the transfer of a pair of electrons from a base to an acid.
Given the balanced equation:
2H2 + 02 --> 2H20
How many grams of H20 is produced if you have 7g of O2
Answer: 7.88375g
Explanation:
Here is the dimensional analysis table
7g O2 | 1 mol O2 | 2 mol H2O | 18.02 g H2O
| 32 g O2 | 1 mol O2 | 1 mol H2O
You use grams to convert to moles of O2, then use that to find grams of H20
What is the main difference between rain and hail?
Answer:
Rain is a liquid and hail is a solid.
A stock solution was created by adding 0.1042 g of lead (II) nitrate to a 100.00 mL volumetric flask and diluting to volume with deionized water. A diluted solution was then created by removing 5.00 mL of the stock solution and placing into into a 50.00 mL volumetric flask and then diluting to volume with deionized water. What is the concentration (in molarity, M) of the diluted solution
Answer: The molarity of diluted solution is 0.00031 M
Explanation:
Molarity of a solution is defined as the number of moles of solute dissolved per liter of the solution.
[tex]Molarity=\frac{n\times 1000}{V_s}[/tex]
where,
n = moles of solute
[tex]V_s[/tex] = volume of solution in ml
moles of [tex]Pb(NO_3)_2[/tex] = [tex]\frac{\text {given mass}}{\text {Molar mass}}=\frac{0.1042g}{331.2g/mol}=0.00031mol[/tex]
Now put all the given values in the formula of molality, we get
[tex]Molarity=\frac{0.00031mol\times 1000}{100ml}=0.0031M[/tex]
According to the dilution law,
[tex](stock)M_1V_1=M_2V_2(dilute)[/tex]
Putting in the values we get:
[tex]0.0031\times 5.00=M_2\times 50.00[/tex]
[tex]M_2=0.00031M[/tex]
Therefore, the molarity of diluted solution is 0.00031 M
A ___________ ion is made of 2 or more atoms of different elements
O nuclear
O polyatomic
O magnetic
O mono-atomic
Answer: polyatomic
Explanation:hope you find helpful
What force is required to accelerate a car at a rate of 4 m/s2 if the car has a mass of 37.5 kg?
Answer:150
Explanation:I think because f=MxA and the mass is 37.5 kg while acceleation is 4 m/s^2 and when you multiply that is gets 150 so F=150 N
bromine pentachloride formula
Answer:
Bromine pentafluoride, BrF5
bromine pentafluoride is an interhalogen compound and a fluoride of bromine. It is a strong fluorination reagent. BrF5 finds use in oxygen isotope analysis.
The chemical formula of a compound is obtained from the symbols of the elements that compose the compound. The formula of bromine pentachloride is BrCl5.
In chemistry, compounds are represented using shorthand symbols called chemical formula.
The chemical formula is composed of the symbols of the respective elements that compose the compound as well as the number of atoms of each element that compose the compound.
For the compound bromine pentachloride, there is one bromine atom and five chlorine atoms giving the formula BrCl5.
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2. A plant growing in response to the sunlight.
Gravitropism
Phototropism
Thigmotropism
Hydrotropism
Answer:
Phototropism.
Explanation:
Phototropism is the phenomenon of plants growing in response to light. This is a response to the plants to align or steer towards the source of sunlight, thereby becoming the 'path' to their growth.
The term "photo" means light and "tropism" means "growth" or movement towards". So, we can safely say that phototropism is the scientific and natural phenomenon of plants growing towards or in response to the sunlight.
Thus, the correct answer is phototropism.
Identify the reactants and products in the following chemical equation: Zn +2HCl --> ZnCl2 + H2 *
20 points
A: Reactants: Zn & HCl Products: ZnCl2 & H2
B: Reactants: ZnCl2 & H2 Products: Zn & HCl
C: Reactants: Zn & H2 Products: ZnCl2 & HCl
Answer:
A.
Explanation:
zinc and hydrochloric acid reacts to form zinc chloride and hydrogen.
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if eleanor starts with 25.00 ml of a weak acid (the concentration is 0.1084 m), then how many ml of 0.1817 m naoh has to be added to reach the equivalence point
Answer:
14.91 mL
Explanation:
Assuming the weak acid is monoprotic, we can solve this problem using the equation:
C₁V₁=C₂V₂Where subscript 1 stands for the Volume and Concentration of the weak acid, while 2 stands for those of NaOH.
We input the data:
25.00 mL * 0.1084 M = 0.1817 M * V₂And solve for V₂:
V₂ = 14.91 mLThe volume of 0.1817 M NaOH has to be added to reach the equivalence point is 14.91 mL.
How we calculate the volume?Volume for the given solution will be calculated from the below equation:
M₁V₁ = M₂V₂, where
M₁ = Molarity of weak acid = 0.1084 M
V₁ = volume of weak acid = 25 mL
M₂ = molarity of NaOH = 0.1817 M
V₂ = volume of NaOH = to find?
On putting all these values on the above equation and calculate for V₂ as:
V₂ = (0.1084)(25) / (0.1817) = 14.91 mL
Hence required volume is 14.91 mL.
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How many grams are in 2.4 moles of sulfur?
Answer:
76.96
Explanation:
A mole is Avagadro’s number of atoms of a substance. My periodic table of the elements gives the Gram Atomic Mass of natural sulphur is 32.066 grams/mole. Therefore, 2.4 moles would have a mass of 76.96 grams.
Our most recent mass extension happened about 65million years ago. Describe the effects of this event.
Answer:
To explain what caused this mass extinction, scientists have focused on events that would have altered our planet's climate in dramatic, powerful ways. The leading theory is that a huge asteroid or comet slammed into Earth 65 million years ago, blocking sunlight, changing the climate and setting off global wildfires.
What is total distance traveled?
What is the displacement (change in positions)
Answer:
Exercise 1
a) 140 m
b) 100 m
c) 180 m
d) 140 m
Exercise 2
a) 20 yards
b) 30 yards
c) 20 yards
d) 55 yards
Exercise 3
a) 11 Kilometers
b) 7 Kilometers
Explanation:
Exercise 1
Distance from B to C = 140 m
Distance from to D = 100 m
Total distance = 100+40+40 = 180 m
Total displacement i.e. distance between A and D is 140 m
Exercise 2
a) Distance from B to C = 35 -15 = 20 yards
b) Distance from C to D = 5 + 35 = 30 yards
c) Distance from B to D = 5 + 15 = 20 yards
d) Displacement = 5 + 50 = 55 yards
Exercise 3
a) The total distance travelled = 5 + 2 + 4 = 11 Kilometers
b) Displacement = 5-2 + 4 = 7 Kilometers
According to 2011/Chemistry Reference Tables
A. The electronegativity value of Cobalt is higher than the electronegativity value of Nickel
B. The electronegativity value of nitrogen is higher than the electronegativity value of fluorine
C. The electronegativity value of calcium is lower than the electronegativity value of silicon
D. The electronegativity value of boron is lower than the electronegativity value of beryllium
Answer:
C
Explanation:
C. The electronegativity value of calcium is lower than the electronegativity value of silicon
is the only correct statement.
Ammonia is produced by the chemical reaction of hydrogen and nitrogen
N2 + 2H2 → 2NH3
How many moles of H2 are needed to react with 1.8 moles of N2
Answer:
3.6 mol H₂
Explanation:
N₂ + 2H₂ → 2NH₃In order to convert from N₂ moles to H₂ moles we need to use a conversion factor. This conversion factor has to have N₂ moles in the denominator and H₂ moles in the numerator, using the stoichiometric coefficients of the reaction, as follows:
1.8 mol N₂ * [tex]\frac{2molH_2}{1molN_2}[/tex] = 3.6 mol H₂