Answer:
An atom with one or two valence electrons more than a closed shell The number of valence electrons of an element can be determined Groups 3-12 (transition metals), 2* (The 4s shell is complete and cannot hold any more electrons) in explaining the molecular structure of many organic compounds.
Explanation:
Do u believe that you are beautiful/handsome?
Yes or No?
You have a 0.8 L of a 0.5 M HCl solution. How many moles of HCl does this solution contain?
Answer:
[tex]\boxed {\boxed {\sf 0.4 \ mol \ HCl}}[/tex]
Explanation:
Molarity is concentration measured in moles per liters. It is the number of moles of solute per liters of solution. The formula is:
[tex]molarity= \frac{moles \ of \ solute}{liters \ of \ solution}}[/tex]
We know the solution of HCl has a molarity of 0.5 molar and there are 0.8 liters of solution.
1 molar (M) is equal to 1 mole per liter. Let's convert the molarity of 0.5 M HCl to 0.5 mol HCl per liter. This will make unit cancellation easier.The moles of solute or HCl are unknown, so we can use x. Now, we can substitute all known values into the formula.
[tex]0.5 \ mol \ HCl /L = \frac {x}{0.8 \ L}[/tex]
Since we are solving for the moles of solute (x), we must isolate the variable. It is being divided by 0.8 liters. The inverse of division is multiplication, so we multiply both sides by 0.8 L.
[tex]0.8 \ L *0.5 \ mol \ HCl /L = \frac {x}{0.8 \ L} *0.8 \ L[/tex]
[tex]0.8 \ L *0.5 \ mol \ HCl /L=x[/tex]
The units of liters (L) cancel.
[tex]0.8 * 0.5 \ mol \ HCl= x[/tex]
[tex]0.4 \ mol \ HCl=x[/tex]
This solution contains 0.4 moles of HCl.
A balloon is filled with 3.50 L of water at 24.0°C. What is the volume of the water at 307 K?
Answer:
what is the volume of the water at 307 k?
Determine the empirical formula for a compound that contains 87.5%
Si and 12.5% H.
Select one:
O
a. SiH4
b. Si3H12
c. SizH4
d. Si4H
Answer:
Solution. So, the empirical formula of the compound is NH2.
Explanation:
thank me later
Answer:
I don't know but I have to answer cause this is the step
Explanation:
which class do u read its so hard i read in only class6
is benzene saturated or unsaturated?
Answer:
Benzene shows that it is actually unsaturated because it adds hydrogen or chlorine, although only when allowed to react under very vigorous conditions (higher temperature or pressure) compared to those required for alkenes and alkynes.
Explanation:
Propane is used as a fuel for camp stoves. It undergoes combustion to form carbon dioxide and water.
C3H3 +502 – 3 CO2 + 4H20
Determine the number of molecules of propane needed to produce 10.01 liters of carbon dioxide
Answer:
[tex]8.97x10^{22}molecules C_3H_8[/tex]
Explanation:
Hello there!
In this case, according to the given chemical reaction and the fact that 22.4 L of a gas are occupied by 1 mol at standard pressure and temperature conditions, it will be possible for us to calculate the number of molecules of propane, by using the Avogadro's number, the 1:3 mole ratio with carbon dioxide and the aforementioned volume-mole ratio to obtain:
[tex]10.01LCO_2*\frac{1molCO_2}{22.4LCO_2}*\frac{1molC_3H_8 }{3molCO_2} *\frac{6.022x10^{23}molec\ C_3H_8}{1molC_3H_8} \\\\=8.97x10^{22}molecules C_3H_8[/tex]
Regards!
A student is titrating 25.00 ml of a weak monoprotic acid solution with an unknown concentration. When setting up the experiment, the student inadvertently uses another team's solution of NaOH. The solution used has a lower concentration than the solution standardized by the student. Select all of the following statements that are true.
a) The pH at the equivalence point will be the same
b) The error will result in a calculated concentration that is higher than the actual concentration
c) You will be able to identify the acid based on the pka value that is determined from the titration curve
d) The pH at the 1/2 equivalence point will be the same
e) The titration will require less volume to react the equivalence point than if the student used their standardized solution
Answer:
c) and d) are true
Explanation:
In this case, let's analyze each statement and see if it's true or not and why. All of this statements comes of the fact of what would have happen if you were not making the mistake, so you are comparing this case to the case that were supposed to be. Now let's analyze the statements:
a) pH at the equivalence point will be the same.
As the concentration of the NaOH is lower than the one that you prepared, it means that we require more volume of this base to reach the equivalence point, therefore, the pH would be different (not so far but still different), so this stament is FALSE.
b) Error result in a calculated concentration higher than the actual concentration.
In this case, the concentration of the acid will not depend of the concentration of the base, because we have a monoprotic acid and a monoprotic base, so the relation between those in a mole ratio is 1:1. The only thing that is being affected is the required volume of the base to reach the equivalence point, but the concentration of the acid will be the same. So this statement is FALSE.
c) Able to identify the acid based on the pKa value that is determined from the titration curve.
In this case, even if we use a base with a lower concentration, the titration curve will not be affected and the pKa of the monoprotic acid will be the same. This is because pKa is related to the acid only, and is a constant value that tell us how strong an acid is, so no matter how much base we add, the pKa is constant and will not be affected. This statement is TRUE.
d) The pH at the 1/2 equivalence point will be the same
In all cases, when the titration is reaching the half equivalence point, pH will always be the same as the pKa. The only thing that changes is the required volume to reach that point. For example, with the standard base you prepared, it requires 10 mL while with the lower concentration base, we need 15 mL, but still, reach half the equivalence point so, the pH is the same as pKa. This statement is TRUE.
e) Titration requires less volume to reach equivalence point.
As it was stated in the previous cases, the base has a lower concentration, therefore, we will need more volume of base to reach the equivalence point and equals the mole of base and acid. This will only be true if the concentration is higher, but its not the case. The statement is FALSE.
Hope this helps
A 0.150-kg sample of a metal alloy is heated at 540 Celsius an then plunged into a 0.400-kg of water at 10.0 Celsius, which is contained in a 0.200-kg aluminum calorimeter cup. The final temperature of the system is 30.5 Celsius. What is the specific heat of the metal alloy in J/Kg.Celsius
Answer:
[tex]C_{alloy}=0.497\frac{J}{g\°C}[/tex]
Explanation:
Hello there!
In this case, according to this calorimetry problem on equilibrium temperature, it is possible for us to infer that the heat released by the metal allow is absorbed by the water for us to write:
[tex]Q_{allow}=-(Q_{water}+Q_{Al})[/tex]
Thus, by writing the aforementioned in terms of mass, specific heat and temperature, we have:
[tex]m_{alloy}C_{alloy}(T_{eq}-T_{alloy})=-(m_{water}C_{water}(T_{eq}-T_{water})+m_{Al}C_{Al}(T_{eq}-T_{Al})[/tex]
Then, we solve for specific heat of the metallic alloy to obtain:
[tex]C_{alloy}=\frac{-(m_{water}C_{water}(T_{eq}-T_{water})+m_{Al}C_{Al}(T_{eq}-T_{Al})}{m_{alloy}(T_{eq}-T_{alloy})}[/tex]
Thereby, we plug in the given data to obtain:
[tex]C_{alloy}=\frac{-(400g*4.184\frac{J}{g\°C} (30.5\°C-10.0\°C)+200g*0.900\frac{J}{g\°C}(30.5\°C-10.0\°C)}{150g(30.5\°C-540\°C)} \\\\C_{alloy}=0.497\frac{J}{g\°C}[/tex]
Regards!
What occurs when a reaction reaches equilibrium?
1)The concentration of the reactants increases.
2)The concentration of the products increases
3)The rate of the forward reaction is equal to the rate of the reverse reaction
4)The rate of the forward reaction is slower that the rate of the reverse reaction.
Answer:
3)The rate of the forward reaction is equal to the rate of the reverse reaction
Answer:
The Rate of Forward Reaction is equal to the rate of the reverse reaction.
Explanation:
Hope this helps :)
which formulas could represent the empirical formula and the molecular formula of a given compound?
A. CH2O, C4H6O4
B. CHO, C6H12O6
C. CH4, C5H12
D. CH2, C3H6
Answer:
d
Explanation:
d
The formulas which could represent the empirical formula and the molecular formula of a given compound are CH₂, C₃H₆ as the smallest possible is 2 which on multiplying the subscripts of empirical formula give molecular formula.
What is empirical formula?Empirical formula of a compound is defined as the simplest whole number ratio of atoms which are present in a compound.It does not make any mention of the arrangement of atoms or the number of atoms. The empirical formula gives information about the ratio of number of atoms which are present in a compound.
Molecular formula is determined from the empirical formula by dividing the molar mass of a compound by the empirical formula mass. The resultant which should be a whole number or very close to the whole number , then the subscripts are multiplied by the whole number to get the molecular formula.
Learn more about empirical formula,here:
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Find the mass of copper that was
heated from 32°C to 130°C by using
5400 joules of heat. Cou=.385 J/goC
Answer:
143.12 g
Explanation:
From the question given above, the following data were obtained:
Initial temperature (T₁) = 32 °C
Final temperature (T₂) = 130 °C
Heat (Q) = 5400 J
Specific heat capacity (C) = 0.385 J/gºC
Mass (M) =?
Next, we shall determine the change in temperature of copper. This can be obtained as follow:
Initial temperature (T₁) = 32 °C
Final temperature (T₂) = 130 °C
Change in temperature (ΔT) =?
ΔT = T₂ – T₁
ΔT = 130 – 32
ΔT = 98 °C
Finally, we shall determine the mass of copper. This can be obtained as follow:
Change in temperature (ΔT) = 98 °C
Heat (Q) = 5400 J
Specific heat capacity (C) = 0.385 J/gºC
Mass (M) =?
Q = MCΔT
5400 = M × 0.385 × 98
5400 = M × 37.73
Divide both side by 37.73
M = 5400 / 37.73
M = 143.12 g
Therefore, the mass of copper is 143.12 g
Dau coroana va roggg!!!!!!
Answer:
it's very easy and simple answer u can't do it
How much water, in grams, can be made from 1.84 × 1024 hydrogen molecules?
Answer:
55.0g water can be made
Explanation:
To solve this question, we must convert the molecules of H2 to moles using Avogadro's constant. With the moles, and the reaction:
H2 + 1/2O2 → H2O
We can find the moles of H2O = Moles H2 and its mass of using molar mass of water -H2O = 18.01g/mol-
Moles H2 = Moles H2O:
1.84x10²⁴ molecules * (1mol / 6.022x10²³ molecules) = 3.055 moles H2O
Mass:
3.055 moles H2O * (18.01g / mol) = 55.0g water can be made
I really need helpp
Answer:
option b
Explanation:
Water forms according to the equation below:
2H2(g) + O2(g) 2H2O(g) es001-2= -483.64 kJ
How much energy is released during the formation of 1 mol H2O(g)?
Answer:
The first blank is: -241.82 kJ
The second blank is: 483.64
Explanation:
Edge 21'
Can someone help me out, thanks
Answer:
See EXPLANATION
Explanation:
We must bear in mind that in balancing chemical reaction equations, the number of atoms of each element on the right hand side must be the same as the number of atoms of the same element on the left hand side of the reaction equation. This follows from the law of conservation of mass.
Based on this;
There are two oxygen atoms on the left hand side of the reaction equation, thus total mass of oxygen = 2 * 16 amu = 32 amu
There are two oxygen atoms on the product side of the reaction equation, thus the total mass of oxygen = 2 * 16 amu = 32 amu
How did the invention of the telescope help the Italian scientist Galileo in 1609 observe the moon and see the mountains, valleys, and craters? Answer A A telescope is an instrument that magnifies tiny objects to make them appear bigger B A telescope is an instrument that magnifies distant objects to make them appear closer C A telescope is an instrument that illuminates tiny objects to make them appear bigger D A telescope is an instrument that illuminates distant objects to make them appear closer
Answer:
I think it's
(A) A telescope is an instrument that magnifies tiny objects to make them appear bigger
What effect does photosynthesis have on Earth’s atmosphere?
i need help who ever helps me will get a Brainliest
Photosynthesis removes both carbon dioxide and oxygen from the atmosphere.
Photosynthesis removes carbon dioxide from the atmosphere and adds oxygen to the atmosphere.
Photosynthesis adds both carbon dioxide and oxygen to the atmosphere.
Photosynthesis removes oxygen from the atmosphere and adds carbon dioxide to the atmosphere.
Question 1 (1 point)
It is not necessary to balance an equation to find the correct mole ratios.
True
False
Answer:
false
Explanation:
cozz you'll need it inorder to find the correct mole ratio
If 3.13 mol of an ideal gas has a pressure of 2.33 atm and a volume of 72.31 L, what is the temperature of the sample in degrees Celsius?
Answer:
382.49 C degree Celsius
Explanation:
Hello,
This problem deals with understanding the ideal gas law which hopes to predict how ideal gases might behave in any given condition. I listed the formula below and we are basically just going to solve for temperature by rearranging the equation as seen on the picture (there's also other rearranged ones in case you need to solve for those).
Universal gas constant R has a value of 0.0821 L * atm/(mole * K) when working with these given units so it will be part of this equation. R value changes based on what units you have.
T = PV/nR
= (2.33) (72.31) / (3.13)(0.0821)
= 655.64 K
Question is asking temperature in celsius so we employ the formula attached below:
C = K - 273.15
= 655.64-273.15
= 382.49 degree Celsius
382.49 degree Celsius is the answer!
How many stable Lewis resonance structures does NO2- HAVE
3
1
2
4
Answer:
2
Explanation:
it has a total of 17 valence electrons
What is the limiting reactant in the following equation? How much Fe2O3 will be produced if 2.1 g of Fe with 2.1 g of O2?
4 Fe + 3O2 —> 2Fe2O3
Answer:
Fe is limiting, and it will produce .0188 mols of Fe2O3
Explanation:
after you convert both Fe and O2 to mols by using their molar mass, you see there is less Fe than O2 so that is your limiting reactant. To find the amount of Fe2O3 you devide the limiting reactant by it's coefeciant (4) then multiply it by the products coefficant (2). Let me know if you have any questions
The heat of combustion per mole for acetylene, C2H2(g), is -1299.5 kJ/mol. Assuming that the combustion products are CO2(g) and H2O(l), and given that the enthalpy of formation is -393.5 kJ/mol for CO2(g) and -285.8 kJ/mol for H2O(l), find the enthalpy of formation of C2H2(g).
Answer: The heat of combustion per mole for acetylene is 227.7 kJ/mol.
Explanation:
The combustion equation of acetylene is as follows.
[tex]C_{2}H_{2} + \frac{5}{2}O_{2} \rightarrow 2CO_{2} + H_{2}O[/tex]
Formula to calculate enthalpy of formation for a reaction is as follows.
[tex]\Delta H^{o}_{rxn} = \sum \Delta H_{products} - \sum \Delta H_{reactants}\\\Delta H^{o}_{rxn} = [2\Delta H^{o}_{f}(CO_{2}) + \Delta H^{o}_{f} (H_{2}O)] - [\Delta H^{o}_{f}(C_{2}H_{2}) + \frac{5}{2} \Delta H^{o}_{f} O_{2}]\\-1299.5 = 2(-393.5) + (-285.8) - \Delta H^{o}_{f} (C_{2}H_{2})\\\Delta H^{o}_{f} (C_{2}H_{2}) = 227.7 kJ/mol[/tex]
Thus, we can conclude that heat of combustion per mole for acetylene is 227.7 kJ/mol.
What do scientists use the term “light-year” to describe?
Answer:
Astronomers measure distance in space or the distance light travels in one Earth year.
" A light-year is how astronomers measure distance in space. It's defined by how far a beam of light travels in one year – a distance of six trillion miles."
18. What is the volume of 0.600 mol of C2H, gas at STP? 19 What is the
Answer:
13.44 L
Explanation:
STP stands for Standard Temperature and Pressure, 273 kelvin and 1 atmosphere.
Under these conditions, 1 mol of any given gas will occupy a volume of 22.4 L.
With the above information in mind we can calculate the volume that 0.600 moles of a gas will occupy:
0.600 mol * 22.4 L/mol = 13.44 Lcarbon tetrachloride is an iconic compound true or false
Answer:
False
Explanation:
Carbon tetrachloride is a covalent compound and not an ionic compound.
This is because it has four nonpolar covalent bonds between carbon and chlorine.
Suppose the available nutrients in the soil of an ecosystem decrease. Over time, which adaptation is MOST LIKELY to evolve among the plants that survive there?
Answer:
Root system will become larger or extend farther
Explanation:
If nutrient in soil decrease, the plant's roots system will likely become larger and extend out deeper and farther to get all the nutrients it possibly can
Octane (C8H18) is found in gasoline. It is burned for fuel in a combustion
reaction. The unbalanced combustion reaction for octane is shown below.
C8h18+ O2 → C02 + H2O + heat
When the reaction is balanced, how many carbon dioxide molecules are
produced for every octane molecule burned?
Answer:
Explanation:
It's 8
What is the volume of a 12.2 g piece of metal with a density of 9.43 g/cm??
Answer:
1.29
Explanation:
You have to find the equation which is d=m/v. d is 9.43=12.2/v. You have to solve for v which you get 1.29
1.29 [tex]cm^3[/tex] is the volume of a 12.2 g piece of metal with a density of 9.43 g/cm.
What is density?Density is the measurement of how tightly a material is packed together.
Density =Mass ÷ volume
9.43=12.2 ÷ V
V = 1.29 [tex]cm^3[/tex]
Hence, 1.29 [tex]cm^3[/tex] is the volume of a 12.2 g piece of metal with a density of 9.43 g/cm.
Learn more about density here:
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What number should be written in front of Na to balance the equation?
Na + MgCl2 → NaCl + Mg
1
2
3
4
In order to balance the chemical equation, the coefficient of Na should be 2.
