Answer:
B
Explanation:
muscles attach to the skeleton in order for the body to be sturdy. as you probably know, the skeletal system is mainly used for providing support to the body so it won't fall down.
Use the periodic table to match each of the following element symbols to its name, atomic mass, or atomic number. (3 points)
1.
Se
2.
S
3.
Sn
a.
Tin
b.
78.971 u (atomic mass)
c.
16 (atomic number)
Answer:
Tin I thunk
Explanation:
I think
Answer:
sn = tin
se = 78.971 u (atomic mass)
s = 16 (atomic number)
Select the pair of compounds that you would expect to form a homogeneous solution based on intermolecular forces. Please choose the correct answer from the following choices, and then select the submit answer button. Answer choices CBr4 and NH3 CCl4 and H2O NH3 and H2O Br2 and HCl
Answer:
NH3 and H2O
Explanation:
In chemistry, the overarching principle of like dissolve like decides the solubility of one substance in another. This principle is ultimately hinged on the idea of intermolecular forces existing between substances. Polar substances dissolve polar substances while nonpolar substances dissolve nonpolar substances in accordance with this principle.
Both NH3 and H2O are polar substances that contain the hydrogen bond. Intermolecular hydrogen bonding interaction accounts for the solubility of NH3 in H20.
The mass of water in a single popcorn kernel was found to be 0.905 grams after it popped at a temperature of 175 °C. Using the information given in the Introduction, calculate the amount of heat in kilojoules required to pop this single kernel if the room temperature was recorded to be 21.0 °C.
Answer:
0.583 kilojoules
Explanation:
The amount of heat required to pop a single kernel can be calculated using the formula as follows:
Q = m × c × ∆T
Where;
Q = amount of heat (J)
m = mass of water (g)
c = specific heat capacity of water (4.184 J/g°C)
∆T = change in temperature
From the given information, m = 0.905 g, initial temperature (room temperature) = 21°C , final temperature = 175°C, Q = ?
Q = m × c × ∆T
Q = 0.905 × 4.184 × (175°C - 21°C)
Q = 3.786 × 154
Q = 583.044 Joules
In kilojoules i.e. we divide by 1000, the amount of heat is:
= 583.04/1000
= 0.583 kilojoules
A sample of carbon dioxide is contained in a 250.0 mL flask at 0.917 atm and 19.3 ∘ C. How many molecules of gas are in the sample?
Answer:
The correct answer is 5.76 x 10²¹ molecules
Explanation:
From the problem, we have the following data:
V= 250.0 mL = 0.25 L
P= 0.917 atm
T= 19.3∘C + 273 = 292.3 K
We can use the ideal gas law to find n (number of moles of gas):
PV= nRT
⇒ n = PV/RT = (0.917 atm x 0.25 L)/(0.082 L.atm/K.mol x 292.3 K) = 9.6 x 10⁻³ mol
We know that 1 mol of any compound is equal to 6.022 x 10²³ molecules of the compound⇒ ratio : 6.022 x 10²³ molecules/1 mol
Thus, we multiply n by the ratio to obtain the number of molecules of gas:
9.6 x 10⁻³ mol x 6.022 x 10²³ molecules/1 mol = 5.76 x 10²¹ molecules
What mass of Al(OH)3 is needed to completely react with 17.9g of HCl?
Answer:
12.8 g
Explanation:
Step 1: Write the balanced neutralization reaction
Al(OH)₃ + 3 HCl ⇒ AlCl₃ + 3 H₂O
Step 2: Calculate the moles corresponding to 17.9 g of HCl
The molar mass of HCl is 36.46 g/mol.
17.9 g × 1 mol/36.46 g = 0.491 mol
Step 3: Calculate the moles of Al(OH)₃ that completely react with 0.491 moles of HCl
The molar ratio of Al(OH)₃ to HCl is 1:3. The reacting moles of Al(OH)₃ are 1/3 × 0.491 mol = 0.164 mol
Step 4: Calculate the mass corresponding to 0.164 moles of Al(OH)₃
The molar mass of Al(OH)₃ is 78.00 g/mol.
0.164 mol × 78.00 g/mol = 12.8 g
Identify the correct order of electron transfers in the electron transport chain starting from FADH2.
Answer:
FADH₂ → Q coenzyme → Complex III → c cytochrome → Complex IV → O₂
Explanation:
During oxidative phosphorylation, the electrons from NADH and FADH₂ are combined with O₂ and the energy released in the process is used to synthesize ATP from ADP.
The components of the electron transport chain are located in the internal part of the mitochondrial membrane in eukaryotic cells, and in the cell membrane in bacteria. The transporters in the electron transport chain are organized into four complexes in the inner mitochondrial membrane. A fifth complex then couples these reactions to the ATP synthesis.
Complex II receives the electrons from the succinate, which is an intermediary in the Krebs cycle. These electrons are transferred to the FADH₂ and then to the Q coenzyme. This liposoluble molecule will transport the electrons from Complex II to Complex III. In this complex, the electrons are transferred from the b cytochrome to the c cytochrome. This c cytochrome, which is a peripheric membrane protein located in the external part of the inner membrane, then transports the electrons to Complex IV where finally they are transferred to the oxygen.
2. In a chemistry experiment, 10 g of urea NH2CONH2 (s) is dissolved in 150 ml of water in a simple calorimeter. A
temperature decrease of 3.7°C is measured. Calculate the molar enthalpy of solution for urea.
Answer:In a chemistry experiment, 10g of urea, NH2CONH2 (s), is dissolved in 150 mL of water in a simple calorimeter. A temperature decrease of 3.7oC is measured. Calculate the molar enthalpy of solution (∆Hs). ... an ideal gas B if 0.622 g sample of gas B occupies a volume of 300 mL at 35 °C and 1.038 atm.
Explanation:
what is the composition and structure of ionic compounds
Answer:
Sodium and chlorine ions come together to form sodium chloride or NaCl. The sodium atom in this compound loses an electron to become Na+, while the chlorine atom gains an electron to become Cl-. Together, they form a neutral compound because the ions balance each other out.
Explanation:
If 6.81 mol of an ideal gas has a pressure of 2.99 atm and a volume of 94.35 L, what is the temperature of the sample?
Answer:
504.57 K.
Explanation:
From the question given above, the following data were obtained:
Number of mole (n) = 6.81 moles
Pressure (P) = 2.99 atm
Volume (V) = 94.35 L
Gas constant (R) = 0.0821 atm.L/Kmol
Temperature (T) =.?
Using the ideal gas equation, the temperature of the ideal gas can be obtained as follow:
PV = nRT
2.99 × 94.35 = 6.81 × 0.0821 × T
282.1065 = 0.559101 × T
Divide both side by 0.559101
T = 282.1065 / 0.559101
T = 504.57 K.
Thus, the temperature of the ideal gas is 504.57 K.
Consider a three-dimensional model of methane as seen here in two dimensions. If we use VSEPR theory to describe the geometry of a methane molecule we say its shape is. A) Linear. B) Tetrahedral. C)Trigonal Planar. D)Trigonal Bipyramidal
Answer:B
Explanation:
Tetrahedral I took the test
Answer:
B is the answer'
Explanation:
Which body of water will have a greater influence on an area?
A. river
B. lake
C. stream
D. ocean
Answer:
The correct option is A
Explanation:
Water from a river is used for many activities in a community. These activities could include (but not limited to) tourism, drinking for animals, local transport, irrigation for nearby farming, recreation (as in swimming), habitat for some living organisms among others. Rivers are not limited by what limits the influence of oceans such as taste (it's saltiness, which cannot be used in farming also) and wave current.
The graph shows the distance an object travel in 11 seconds which answer choice best describes the movement of the object between the times of 0 and 6 seconds on the graph
Answer:
its moving at a constant speed
Explanation:
i did the test and got it right
The specific heat of liquid bromine is 0.226 J/g-K. How much heat (J) is required to raise the temperature of 10.0 mL of bromine from 25.00 °C to 27.30 °C? The density of liquid bromine: 3.12 g/mL
Answer:
16.2 J
Explanation:
Step 1: Given data
Specific heat of liquid bromine (c): 0.226 J/g.KVolume of bromine (V): 10.0 mLInitial temperature: 25.00 °CFinal temperature: 27.30 °CDensity of bromine (ρ): 3.12 g/mLStep 2: Calculate the mass of bromine
The density is equal to the mass divided by the volume.
ρ = m/V
m = ρ × V
m = 3.12 g/mL × 10.0 mL
m = 31.2 g
Step 3: Calculate the change in the temperature (ΔT)
ΔT = 27.30 °C - 25.00 °C = 2.30 °C
The change in the temperature on the Celsius scale is equal to the change in the temperature on the Kelvin scale. Then, 2.30 °C = 2.30 K.
Step 4: Calculate the heat required (Q) to raise the temperature of the liquid bromine
We will use the following expression.
Q = c × m × ΔT
Q = 0.226 J/g.K × 31.2 g × 2.30 K
Q = 16.2 J
The equilibrium constant, Kc, for the following
reaction is 10.5 at 350 K.
2CH2Cl2(g) double arrow CH4(g) + CCl4(g)
If an equilibrium mixture of the three gases in a 12.7
L container at 350 K contains 0.205 mol of
CH2Cl2(g) and 0.414 mol of CH4, the equilibrium
concentration of CCl4 is......
mol.
Answer:
2CH2Cl2(g) Doublearrow CH4(g) + CCl4(g)
0.205 moles of CH2Cl2 is introduced. Let by the time an equilibrium is reached x moles each of CH4 and CCl4 are formed => remaining moles of CH2Cl2 are 0.205-x
i.e at equilibrium the concentration on CH2Cl2 is (0.205-2x) mol/L, CH4 is x mol/L, CCl4 is x mol/L
Now the equilibrium constant equation : K = [CH4][CCl4]/[CH2Cl2]^2 ([.] - stands for concentration of the term inside the bracket)
10.5 = x*x/(0.205-2x)^2
=> 10.5(4x^2-0.82x+0.042) = x^2
=>42x^2-8.61x+0.441=x^2
=>41x^2-8.61x+0.441 = 0
This is a Quadratic in x, solving for the roots, we get x = 0.0886 , x = 0.121
The second solution for x will lead 0.205-2x to become negative, so is an infeasible solution.
Therefore equilibrium concentrations of the products and reactants correspond to x=0.0886 and they are , [CH2Cl2] = 0.205-2*0.0886 =0.0278 mol/L , [CH4] = 0.0886 mol/L , [CCl4] = 0.0886 mol/L
2) Why do transition elements show variable
oxidation states
Answer:
These elements show variable oxidation state because their valence electrons in two different sets of orbitals, that is (n-1)d and ns. The energy difference between these orbitals is very less, so both the energy levels can be used for bond formation. Thus, transition elements have variable oxidation states
6. What causes the phases of the moon?
Answer:
The rotation of the Earth.
a sample of hydrogen gas (h2) is mixed with water vapor (h2o (g)). the make sure has a total pressure of 811 torr, and the water vapor has a partial pressure of 12 torr. how many moles of hydrogen gas are present in a 10.0 l mixture at 298k?
Answer:
[tex]n=0.430molH_2[/tex]
Explanation:
Hello!
In this case, considering the partial Dalton's law of partial pressures, we can notice that the total pressure equals the pressure of steam and the pressure of hydrogen, which can be determined as shown below:
[tex]p_T=p_H+p_w\\\\p_H=811torr-12torr=799torr*\frac{1atm}{760torr}\\\\p_H=1.05atm[/tex]
Thus, by using the ideal gas law, we can compute the moles of hydrogen as shown below:
[tex]PV=nRT\\\\n= \frac{PV}{RT}=\frac{1.05atm*10.0L}{0.082\frac{atm*L}{mol*K}*298K}\\\\n=0.430molH_2[/tex]
Best regards!
A geneticist has discovered a new compound that is made up of a small number of identical
subunits. The subunits are joined end to end in long chains. Based on this information, what
best can be concluded about these subunits?
A. They are ketones.
B. They are hydrocarbons.
C. They are monomers.
D. They are polymers.
Answer:
They are monomers.
Explanation:
Edg 2020
Answer:
C.monomers
Explanation:
edg. 2020 read and use common sense
Identify which of the following equations are balanced.A. 6Li(s)+N2(g)→2Li3N(s)6Li(s)+N2(g)→2Li3N(s).B. 2KMnO4(s)→K2MnO4(s)+MnO2(s)+O2(g). C. 2KClO3(s)→2KCl(s)+O2(g)2KClO3(s)→2KCl(s)+O2(g). D. Mg(s)+N2(g)→Mg3N2(s)Mg(s)+N2(g)→Mg3N2(s).
Answer:
love u baby doll thanks for the help
A photovoltaic cell converts light into electrical energy. Suppose a certain photovoltaic cell is only 63.5% efficient, in other words, that 63.5% of the light energy is ultimately recovered. If the energy output of this cell is used to heat water, how many 520 nm photons must be absorbed by the photovoltaic cell in order to heat 10.0 g of water from 20.0°C to 30.0°?
Answer:: A photovoltaic cell converts light into electrical energy. Suppose a certain photovoltaic cell is only 63.5% efficient, in other words, that 63.5% of the light energy is ultimately recovered. If the energy output of this cell is used to heat water, how many 520 nm photons must be absorbed by the photovoltaic cell in order .
Explanation:
30.1 grams of ice at -250^oC would be required how many kj to increase it's temperature to 15.0^ᴏC
Answer:
16.1923 kj
Explanation:
Given data:
Mass of ice = 30.1 g
Initial temperature = -250 °C
Final temperature = 15.0 °C
Energy required = ?
Solution:
Specific heat capacity of ice is 2.03 J/g.°C
Formula:
Q = m.c. ΔT
Q = amount of heat absorbed or released
m = mass of given substance
c = specific heat capacity of substance
ΔT = change in temperature
ΔT = 15.0°C - (-250 °C)
ΔT = 265°C
Q = 30.1 g × 2.03 J/g.°C × 265°C
Q = 16192.3 J
J to kJ:
16192.3 J × 1 KJ /1000 j
16.1923 kj
Which compounds are organic?
a. CO2
b. NaCl
c. C6 H12 O6
d. CH2P (C6H5)3
Answer:
All of them except NaCl
Explanation:
Organic compounds are compound that basically contain carbon-hydogen bonds. Salt (NaCl) doesn't have carbon, and the rest does. So I think that A, C, and D are the answers.
I hope this helps!
Calcium metal reacts with fluorine gas to form solid calcium fluoride. When the reaction is balanced, what coefficient is in front of fluorine gas?
A. 1
B. 2
C. 7
D. 3
Answer:
B= 2
Explanation:
Chemical equation:
Ca + F → CaF₂
Balance chemical equation:
Ca + 2F → CaF₂
Step 1:
Ca + F → CaF₂
Left hand side right hand side
Ca = 1 Ca = 1
F = 1 F = 2
Step 2:
Ca + 2F → CaF₂
Left hand side right hand side
Ca = 1 Ca = 1
F = 2 F = 2
15.0 L of an ideal gas at 298 K and 3.36 atm are heated to 383 K with a new pressure of 5.60 atm. What is the new volume in liters
Answer:
[tex]V_2=11.6L[/tex]
Explanation:
Hello!
In this case, since we volume, pressure and temperature which are all changing, we can use the combined ideal gas law to write:
[tex]\frac{P_1V_1}{T_1} =\frac{P_2V_2}{T_2}[/tex]
Thus, since the final volume V2 is required, by solving for it, we write:
[tex]V_2=\frac{P_1V_1T_2}{T_1P_2}[/tex]
In such a way, we plug in the given data to obtain:
[tex]V_2=\frac{3.36atm*15.0L*383K}{298K*5.60atm}\\\\V_2=11.6L[/tex]
Which means that the process compressed the gas.
Best regards.
What information would you need to determine the most likely resonance structure for the molecule?
A. The formal charge of each atom
B. The polarity of each covalent bond
C. The Lewis structure of the molecule
D. The bond length of each covalent bond
Answer:
The Formal Charge of Each Atom
Explanation:
I just took the test!
Answer:
A. The formal charge of each atom
Explanation:
Select the molecule where free rotation around one or more bonds is not possible. Group of answer choices N2H4 C2Cl4 NH3 C2H6 CCl4
Answer:
C₂Cl₄
Explanation:
To know if free rotation around a bond in a compound is possible, we need to see the structure of the compound (picture in attachment).
In single bonds, which are formed by σ bonds, the atoms are not fixed in a single position, and free rotation is permitted.
Double and triple bonds are formed by a σ bond and one or two π bonds, respectively. These bonds do not allow rotation, since it is not possible to twist the ends without breaking the π bond.
The chloroethylene (C₂Cl₄) has two carbons with an sp2-sp2 hybridization, they are bonded together by a double bond. Free rotation on this bond is not possible, because six atoms, including the carbon atoms, doubly bonded and the four chlorine atoms bonded to them, must be on the same plane.
Question 10
2 pts
(2 points) What is the molarity of a solution when 25.0 mL of 0.500 M NaCl is diluted to 150.0 mL?
Show your work. No work = no credit.
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Answer:
M₂ = 0.08 M
Explanation:
Given data:
Initial volume = 25.0 mL
Initial molarity = 0.500 M
Final volume = 150.0 mL
Final molarity = ?
Solution:
Formula:
M₁V₁ = M₂V₂
0.500 M × 25.0 mL = M₂ × 150.0 mL
M₂ = 0.500 M × 25.0 mL / 150.0 mL
M₂ = 12.5 M.mL /150.0 mL
M₂ = 0.08 M
Ocean waves are hitting a beach with a frequency of 0. 100 HZ the average weight for length is 15.0 M what is the average speed
Answer:
Speed of wave = 1.5 m/s
Explanation:
Given data:
Frequency of wave = 0.100 Hz
wavelength of wave = 15.0 m
Average speed = ?
Solution:
Speed of wave = frequency × wavelength
Speed of wave = 0.100 Hz × 15.0 m
Hz = s⁻¹
Speed of wave = 1.5 m/s
If MgCl2 (aq) has a molarity of 2.5 M, then the molarity of the Cl-1 ions is ____ M.
Answer:
molarity of Cl⁻ ions = 5.0 M
Explanation:
The molarity of a solution expresses the amount in moles of a solution present in a litre of solvent. Its unit is mol/L or mol/dm³ written as M.
MgCl₂ when dissolved to form an aqueous solution dissociates into positive and negative ions, Mg²⁺and Cl⁻ ions.
Equation of the dissociation of MgCl₂ in aqueous solution is given below:
MgCl₂(aq) -----> Mg²⁺(aq) + 2Cl⁻(aq)
1 mole of aqueous MgCl₂ produces 2 moles of chloride ions, Cl⁻
Molar concentration of MgCl₂(aq) = 2.5 M
Molarity of chloride ions = number of moles of Cl⁻ ions * molarity of MgCl₂
molarity of Cl⁻ ions = 2 * 2.5 M
molarity of Cl⁻ ions = 5.0 M
A mass scale reads 10 kilograms on earth, what would it read on the moon?