Answer:
c
Explanation:
use %composition given to calculate emperical 4mular
The empirical formula of the compound having 57.5% Na, 40.0% O, and 2.5% H is NaOH (Option C)
Data obtained from the questionNa = 57.5%O = 40%H = 2.5%Empirical formula =?How to determine the empirical formulaDivide by their molar mass
Na = 57.5 / 23 = 2.5
O = 40 / 16 = 2.5
H = 2.5 / 1 = 2.6
Divide by the smallest
Na = 2.5 / 2.5 = 1
O = 2.5 / 2.5 = 1
H = 2.5 / 2.5 = 1
Thus, the empirical formula of the compound is NaOH
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A 49.7 mL sample of gas in the cylinder is warm from 20°C to 92°C. What is the volume of the final temperature
Answer:
61.9mL
Explanation:
Given parameters:
Initial volume = 49.7mL
Initial temperature = 20°C = 293K
Final temperature = 92°C = 365K
Unknown:
Final volume = ?
Solution:
To solve this problem, we simply apply the Charles's law which states that "the volume of a fixed mass of a gas varies directly as it absolute temperature if the pressure is constant";
[tex]\frac{V1}{T1} = \frac{V2}{T2}[/tex]
V and T are volume and temperature values
1 and 2 are initial and final states
Now insert the parameters and solve;
[tex]\frac{49.7}{293}[/tex] = [tex]\frac{V2}{365}[/tex]
V2 = 61.9mL
Answer rrrrrrrrr....
Answer:
The answer is "Option b".
Explanation:
[tex]\to \text{number of moles} = \frac{\text{number of atoms}}{\text{avogadro number}}[/tex]
[tex]= \frac{7.0 \times 10^{19}}{6.0221 \times 10^{23}}\\\\= 1.16 \times 10^{-4} \ moles\\\\ =1.2 \times 10^{-4} \ moles[/tex]
[tex]\to \text{sample mass}= \text{number of moles} \times \text{molar mass}[/tex]
[tex]=1.16 \times 10^{-4}\times 58.9\\\\=0.00685 \\\\ = 6.85\ g[/tex]
An object on top of a building has a GPE of 23,048j and a mass of 39kg, What is the height of the object
Answer:
59.1 mExplanation:
The height of the object can be found by using the formula
[tex]h = \frac{p}{mg } \\ [/tex]
where
p is the potential energy
m is the mass
h is the height
g is the acceleration due to gravity which is 10 m/s²
From the question we have
[tex]h = \frac{23048}{39 \times 10} = \frac{23048}{390} \\ = 59.0974...[/tex]
We have the final answer as
59.1 mHope this helps you
When 80.0 mL of a 0.812 M barium chloride solution is combined with 40 mL of a 1.52 M potassium sulfate solution, 10.8 g of barium sulfate precipitates. What is the % yield of this reaction
Answer:
76.1%
Explanation:
The reaction that takes place is:
BaCl₂ + K₂SO₄ → BaSO₄ + 2KClFirst we determine how many moles of each reactant were added:
BaCl₂ ⇒ 80 mL * 0.812 M = 64.96 mmol BaCl₂ K₂SO₄ ⇒ 40 mL * 1.52 M = 60.8 mmol K₂SO₄Thus K₂SO₄ is the limiting reactant.
Using the moles of the limiting reactant we calculate how many moles of BaSO₄ would have been produced if the % yield was 100%:
60.8 mmol K₂SO₄ * [tex]\frac{1mmolBaSO_4}{1mmolK_2SO_4}[/tex] = 60.8 mmol BaSO₄Then we convert that theoretical amount into grams, using the molar mass of BaSO₄:
60.8 mmol BaSO₄ * 233.38 mg/mmol = 14189.504 mg BaSO₄14189.504 mg BaSO₄ / 1000 = 14.2 g BaSO₄Finally we calculate the % yield:
% yield = 10.8 g / 14.2 g * 100 %% yield = 76.1%please help me this is due soon i really need help :'c
************24 POINTS!*********
Answer:
carbohydrates, lipids, proteins, and nucleic acids.
Explanation:
Carbohydrates serve several key functions in your body. They provide you with energy for daily tasks and are the primary fuel source for your brain's high energy demands.
The functions of lipids include storing energy, signaling, and acting as structural components of cell membranes. Lipids have applications in the cosmetic and food industries as well as in nanotechnology.
Protein has many roles in your body. It helps repair and build your body's tissues, allows metabolic reactions to take place and coordinates bodily functions. In addition to providing your body with a structural framework, proteins also maintain proper pH and fluid balance.
The functions of nucleic acids have to do with the storage and expression of genetic information. Deoxyribonucleic acid (DNA) encodes the information the cell needs to make proteins. A related type of nucleic acid, called ribonucleic acid (RNA), comes in different molecular forms that participate in protein synthesis.
A solution of 62.4 g of a covalent compound in enough water to make 1.000 L of solution has an osmotic pressure of 0.305 atm at 25°C. Assume the covalent compound does not dissociate in the solution. Based on these data, what is the molar mass (in g/mol) of covalent? Round your answer to the nearest whole number and do not include units with your answer.
Answer:
4.99 × 10³ g/mol
Explanation:
Step 1: Given and required data
Mass of the covalent compound (m): 62.4 gVolume of the solution (V): 1.000 LOsmotic pressure (π): 0.305 atmTemperature (T): 25°C = 298 KStep 2: Calculate the molarity (M) of the solution
The osmotic pressure is a colligative pressure. For a covalent compound, it can be calculated using the following expression.
π = M × R × T
M = π / R × T
M = 0.305 atm / (0.0821 atm.L/mol.K) × 298 K
M = 0.0125 M
Step 3: Calculate the moles of solute (n)
We will use the definition of molarity.
M = n / V
n = M × V
n = 0.0125 mol/L × 1.000 L = 0.0125 mol
Step 4: Calculate the molar mass of the compound
0.0125 moles of the compound weigh 62.4 g. The molar mass is:
62.4 g/0.0125 mol = 4.99 × 10³ g/mol
calculate the enthalpy change for reaction in kjmol-1
Answer:
I got
−
902 kJ
for the reaction as-written. How would you rewrite this into
kJ/mol NH
3
?
The standard molar enthalpy of formation is for the formation of
1 mol
of product from its elements as they exist in nature at
25
∘
C
and
1 atm
. For example...
1
2
N
2
(
g
)
+
3
2
H
2
(
g
)
→
NH
3
(
g
)
,
Δ
H
∘
f
(
NH
3
(
g
)
)
=
−
45.9 kJ/mol
But that also means formation of elements in their standard states must yield zero enthalpy change:
1
2
O
2
(
g
)
→
1
2
O
2
(
g
)
,
Δ
H
∘
f
(
O
2
(
g
)
)
=
0
That means we can simply derive from Hess's law and that fact to get:
Δ
H
∘
r
x
n
=
∑
P
n
P
Δ
H
∘
f
,
P
−
∑
R
n
R
Δ
H
∘
f
,
R
where
n
indicates the mols of product
P
or reactant
R
. Here we actually have just summed many formation reactions together that we know have
Δ
H
∘
r
x
n
=
Δ
H
∘
f
.
Here we have:
Δ
H
∘
r
x
n
=
[
4 mols NO
(
g
)
⋅
Δ
H
∘
f
,
N
O
(
g
)
+
6 mols H
2
O
(
g
)
⋅
Δ
H
∘
f
,
H
2
O
(
g
)
]
−
[
4 mols NH
3
(
g
)
⋅
Δ
H
∘
f
,
N
H
3
(
g
)
+
0 kJ/mol
]
where we have set a zero contribution
O
2
(
g
)
right off the bat.
=
[
4 mols NO
(
g
)
⋅
91.3 kJ/mol
+
6 mols H
2
O
(
g
)
⋅
−
241.8 kJ/mol
]
−
[
4 mols NH
3
(
g
)
⋅
−
45.9 kJ/mol
+
0 kJ/mol
]
=
[
−
1085.6 kJ
]
−
[
−
183.6 kJ
]
=
−
902 kJ
for the reaction as-written.
Explanation:
In a climatological sense, dryness is a function of both annual rainfall and ________.
This a geology question.
Answer:
In a climatological sense, dryness is a function of both annual rainfall and evaporation
How many moles of carbon dioxide are produced when 12.1 g of HF are reacted with an excess amount of sodium carbonate? Na2CO3 (aq) + 2 HF (aq) → H2O (ℓ) + CO2 (g) + 2 NaF (aq)
Answer:
0.3025 moles of CO₂ are produced
Explanation:
Reaction is: Na₂CO₃ (aq) + 2 HF (aq) → H₂O (l) + CO₂ (g) + 2 NaF (aq)
It is correctly ballanced.
If the given information stays that the excess amount is on the sodium carbonate, the HF is the limiting reagent.
We see that stoichiometry is 2:1. Moles of produced CO2, will be the half, than the original amount, we have.
Firste step: We convert the mass to moles
12.1 g . 1mol / 20g = 0.605 moles of HF
2 moles of HF can produce 1 mol of CO₂
0.605 moles of HF will produce (0.605 . 1) /2 = 0.3025 moles of CO₂
All of the following are sources of air pollution except
Glycerol is an extremely viscus solution, density of 1.26 g/cm3, that is usually measured by weight. How many grams of glycerol are required for a reaction that calls for 3.16 mL of glycerol.
Taking into account the definition of density, the mass of grlycerol required is 3.9816 g.
Definition of densityDensity is a quantity that is defined as the measurement of the amount of mass in a given volume of a substance.
Then, the expression for the calculation of density is the quotient between the mass of a body and the volume it occupies:
density= mass÷ volume
You can observe that density is inversely proportional to volume: the smaller the volume occupied by a given mass, the higher the density.
Mass of glycerolIn this case, you know that:
Density= 1.26 g/cm³Volume= 3.16 mL= 3.16 cm³ (being 1 mL= 1 cm³)Replacing in the definition of density:
1.26 g/cm³= mass÷ 3.16 cm³
Solving:
mass= 1.26 g/cm³ ×3.16 cm³
mass= 3.9816 g
In summary, the mass of grlycerol required is 3.9816 g.
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Which of the following are lost or gained during a nuclear reaction?
Group of answer choices
Electrons and nucleus
Protons and electrons
Electrons and neutrons
Protons and neutrons
Answer:
I think that is electrons and nucleus
Explanation:
It makes sense
Answer:
Protons and neutrons :)
the outcome or results of the experiment are called the.
A. dependent variable.
B. independent variable.
C controlled variable.
D. No variable
Lithium hydroxide is used in alkaline batteries. Calculate the molarity of a solution prepared by dissolving 1.495 moles of LiOH in enough water to give a final volume of 750. mL.
1) 1.99 M
2) 1.50 M
3) 1.12 M
4) 0.502 M
5) 0.00199
Answer:1)1.99 M
Explanation:
Molarity is given as = moles solute/Liter solution
The solute which is LiOH is already given in moles as 1.495 moles
Given that solution is 750 mL, we convert to liters.
Liters of the solution= mL of the solution x (1 L/1000 mL)
750 mL x (1 L/1000 mL)
0.75 L
Molarity = moles solute/Liter solution
Molarity = 1.495 moles of LiOH/0.75 L of solution
Molarity = 1.99M
The molarity of this solution is 1.99M (moles per liter).
If 4.73 g Ar are added to 3.22 atm He in a 2.00 L cylinder at 27.0 °C. what is the total pressure of the resulting gaseous mixture?
Answer:
4.67 atm
Explanation:
Step 1: Given data
Mass of Ar (mAr): 4.73 gPartial pressure of He (pHe): 3.22 atmVolume of the container (V): 2.00 LTemperature (T): 27.0 °CStep 2: Convert "T" to Kelvin
We will use the following expression.
K = °C + 273.15
K = 27.0 °C + 273.15 = 300.2 K
Step 3: Calculate the moles of Ar
The molar mass of Ar is 39.94 g/mol.
4.73 g × 1 mol/39.94 g = 0.118 mol
Step 4: Calculate the partial pressure of Ar
We will use the ideal gas equation.
pAr × V = nAr × R × T
pAr = nAr × R × T / V
pAr = 0.118 mol × (0.0821 atm.L/mol.K) × 300.2 K / 2.00 L
pAr = 1.45 atm
Step 5: Determine the total pressure of the gaseous mixture
The total pressure of the gaseous mixture is equal to the sum of the partial pressures of the individual gases.
P = pAr + pHe = 1.45 atm + 3.22 atm = 4.67 atm
What do osmosis, diffusion, filtration, and the movement of ions away from like charge all have in common?
Moving material along certain gradients is necessary for osmosis, diffusion, filtration, and the transport of ions away from similar charges.
Osmosis is the flow of solvent molecules over a semi-permeable membrane from an area of lower concentration to a region of higher concentration Molecules diffuse when they travel from one area of higher concentration to another area of lower concentration The process of filtering involves moving liquid substances through a separating material known as a filter in order to separate solid particles from liquid. Due to the difference in pressures between the solid and liquid substances, this process is made feasible. Because of the difference in electrical potentials between the charges, ions move away from like charges.
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Most substances can exist as a solid, liquid, or gas depending on ? ( science
Answer:
The amount of energy in molecules of matter determines the state of matter.
Explanation:
The amount of energy in molecules of matter determines the state of matter. Matter can exist in one of several different states, including gas, liquid, or solid-state.
Answer:
The state of a substance depends on the space between its particles and on the way in which the particles move. The more solid it is the tighter the particles.
PLEASE HELP ME OUT!!!!!
Answer:
89.1942....
Explanation:
abundance x mass on each one, the added all together:
77.742+6.201+5.251
The thermite reaction ,
Fe2O3(s)+2Al(s)⟶2Fe(s)+Al2O3(s),ΔH∘=−851.5kJ/mol
is one of the most exothermic reactions known. Because the heat released is sufficient to melt the iron product, the reaction is used to weld metal under the ocean. How much heat is released per mole of Al2O3produced? How does this amount of thermal energy compare with the energy released when 2 mol of protons and 2 mol of neutrons combine to form 1 mol of alpha particles?
Answer:
Explanation:
1) The ΔH shows the heat of reaction of the reaction illustrated in the question and the negative sign shows the reaction is an exothermic reaction, meaning heat is released in this reaction. The amount of heat released in this reaction is 851.5 kilojoules per mole of Al₂O₃ produced.
2) The thermal energy of this reaction is however very low when compared to the energy released when 2 moles of protons and 2 moles of neutrons combine to form 1 mole of alpha particles. This is because, the reaction illustrated in the (1) above is a normal chemical reaction while the one that involves the protons and neutrons (as described in this section 2) is a nuclear reaction which involves large amount of energy. Nuclear reactions usually involve way larger amount of energy than ordinary chemical reactions.
Under conditions of constant temperature and amount of substance, a plot of pressure VS. volume for an ideal gas will result in:__________.
a) a line
b) a parabola
c) a logarithmic function
d) none of the above
Answer:
d) none of the above
Explanation:
The law that describes the relationship between pressure and volume of an ideal gas (under constant temperature and amount of substance) is Boyle's law.
It states that pressure is inversely proportional to the volume. This would mean that a graph of P vs 1/V would be a line.
See the attached picture for a graph of P vs V.
A plot of pressure VS. volume for an ideal gas will result in d) none of the above
The following things should be considered:
Boyle's law means the law that shows the relationship that lies between the pressure and volume of ideas gas that involved the same temperature and the substance amount.Also, the pressure should be inversly proportional with respect to the volume.Therefore we can conclude that a plot of pressure VS. volume for an ideal gas will result in d) none of the above
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A student knew that it was possible to make copper (II) sulphate crystals by adding copper (II)
carbonate to dilute sulphuric acid and warming the resulting solution to drive off some ofthe
water and then leaving the solution to crystallize. He decided to make copper (II) nitrate crystals
by similar method. The only change he made was to use dilute nitric acid. He left the final
solution for several days but failed to collect any crystals. Explain why the student did not get
any crystals to collect.
(10 marks)
Examiner: ProfM. K. Abekoe
Copper (ii) nitrate is deliquescent and absorbs moisture from the atmosphere. Therefore, no crystals of copper (ii) nitrate are formed after several days.
What are deliquescent substances?Deliquescent substances are substances which when exposed to the atmosphere absorb moisture from the atmosphere to form solutions.
During the preparation of copper (ii) nitrate from copper (ii) carbonate and dilute nitric acid, the product formed is copper (ii) nitrate solution and carbon dioxide is evolved.
The equation of the reaction is given below:
CuCO₃ + HNO₃ → Cu(NO₃)₂ + H₂O + CO₂
In the preparation of copper (II) sulfate crystals, the procedure involves adding copper (ii) carbonate to dilute sulfuric acid and warming the resulting solution to drive off some of the water and then leaving the solution to crystallize.
However, unlike copper (ii) sulfate, copper (ii) nitrate is deliquescent, and as such, it absorbs ,moisture continuously from the atmosphere. Thus, no crystals of copper (ii) nitrate are formed after several days.
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is yeast living or non living?
Answer:
Yeast is living.
Explanation:
Yeast is a type of fungus used in making bread. Fungus is a group of living organisms.
a student made the table shown to list some contact and non contact forces
b bbbbbbbbbbbbbbbbbbbbbbbbbb
Using the periodic table and your knowledge of patterns and trends on the table, which of the following elements is the most reactive?
A. Titanium (Ti, #22)
B. Silicon (Si, #14)
C. Oxygen (0, #8)
D. Argon (Ar, #18)
Based on the periodic trends in the periodic table, the most reactive element is oxygen; option C
What are periodic trends in the periodic table?Periodic trends in the periodic table refers to the periodic variation in the properties of the elements which is observed in the periodic table as one moves across the periodic table from left to right across a period or down a group in the periodic table.
This regular variation is also known as periodicity in the properties of elements.
Some of the periodic trends observed in the periodic table include:
the reactivity of metals increase down a group and from right to left across a periodthe reactivity of non-metals increase in a group from down to top and from left to right across a period across a period.Considering the most reactive element based on the periodic trends:
Titanium, Ti is a transition metal whose reactivity is intermediate as it is found in between group 2 and 3 of the periodic table
Silicon is metalloid which is not very reactive
Oxygen, O is a very reactive non-metal found in group 6A
Argon, is a noble gas which is almost inert.
Therefore, the most reactive element is oxygen.
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How many atoms are there in 13200 g of potassium (k)
Answer:
[tex]20.33\times 10^{26}[/tex] atoms
Explanation:
Given that,
Given mass = 13200 g
Molar mass of potassium = 39.0983 g/mol
Let there are n number of moles. It is equal to mass divided by molar mass. It is equal to :
[tex]n=\dfrac{13200}{39.0983 }\\\\=337.61\ \text{mol}[/tex]
Let there are x atoms in 13200 g of potassium (k). It can be calculated :
[tex]x=n\times N_A\\\\=337.61\times 6.023\times 10^{23}\\\\=20.33\times 10^{26}[/tex]
So, there are [tex]20.33\times 10^{26}[/tex] atoms.
What is the molar mass of Cr3(AsO4)2?
g/mol
To calculate the molar mass of [tex]\rm Cr_3(AsO_4)^2[/tex], we need to determine the sum of the atomic masses of all the individual atoms in the compound.
The atomic masses of the elements are as follows:
Cr (chromium) = 52.00 g/mol
As (arsenic) = 74.92 g/mol
O (oxygen) = 16.00 g/mol
Now, let's calculate the molar mass of [tex]\rm Cr_3(AsO_4)^2[/tex]:
Molar mass of Cr3(AsO4)2
= (3 * molar mass of Cr) + (2 * molar mass of As) + (8 * molar mass of O)
= (3 * 52.00 g/mol) + (2 * 74.92 g/mol) + (8 * 16.00 g/mol)
= 156.00 g/mol + 149.84 g/mol + 128.00 g/mol
= 433.84 g/mol
Therefore, the molar mass of [tex]\rm Cr_3(AsO_4)^2[/tex] is 433.84 g/mol.
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If I formed an ion, what would it's charge likely be and why?
A. -2 because it gains 2 electrons
B. +2 because it gains 2 electrons
C. +4 because it loses 4 electrons
D. -6 because it gains 2 electrons
Answer: -2 because it gains 2 electrons
Explanation:
An ion is considered to be an atom which is formed by gain or loss of electrons.
The ions are classified into two which are called the cation and anion.
The cation is classified as the positive charge formed by loss of electrons.
The anion is classified as the negative charge ion formed by gain of electrons.
On gaining two electrons, the atom would occupy -2 charge.
A car travels 30 miles on one gallon of gasoline. Gasoline costs $4.00 per gallon. Calculate the cost of driving the car 300 miles.
Answer:
40$$$
Explanation:
Reason: 300 miles × 1gallon30miles × $4.001gallon = $40
There are 4.63 x 1023 molecules in 118.3 grams of CCl4.
Select one:
True
False
Explanation:
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If bovine haemoglobin has an extinction coefficient of 30910 L mol-1 cm-1 at 570 nm in PBS, what is the concentration of a solution reading an absorbance of 0.7?
hey sisterrrrrrrrrr its ginger charles here i hear you looking for the answer well this is your lucky day the answer is
Explanation:
The concentration of Bovine Hb with absorbance 0.7 at 570 nm has been 2.264 [tex]\mu[/tex]M.
According to Beer's law, the absorbance of the sample can be given by:
Absorbance = Extinction coefficient [tex]\rm \times[/tex] concentration [tex]\times[/tex] path length
The Bovine Hb has the extinction coefficient = 30910 L/mol/cm
The absorbance = 0.7
The path length has been 1 cm.
The concentration of the Bovine Hb can be given as:
0.7 = 30910 [tex]\times[/tex] concentration [tex]\times[/tex] 1
The concentration of Bovine Hb = 2.264 [tex]\rm \times\;10^-^6[/tex] moles/L
The concentration of Bovine Hb = 2.264 [tex]\rm \mu[/tex]moles/L
The concentration of Bovine Hb = 2.264 [tex]\mu[/tex]M.
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