☛ 299,792,458 meters per second.
1. A positive value for AH for a chemical reaction is an indication of which of the following?
A. Reactants have higher potential energy and the reaction is endothermic.
B. Reactants have higher potential energy, and the reaction is exothermic.
C. Products have higher potential energy, and the reaction is endothermic.
D. Products have higher potential energy, and the reaction is exothermic.
Answer:
C. Products have higher potential energy, and the reaction is endothermic.
Classify each aqueous solution as acidic, basic, or neutral at 25 °C.
Acidic
Basic
Neutral
pH - 3.41
pH = 10.25
pH = 7.00
[H+] -3.5 x 10-5
[H+] - 6.7 x 10-9
[OH-]-5.8 x 10-4
[H0] -1.0 x 10-7
[OH-] - 4.5 x 10-13
Answer:
pH - 3.41 = acidic
pH = 10.25 = basic
pH = 7.00 = neutral
[H+] -3.5 x 10-5 = acidic
[H+] - 6.7 x 10-9 = basic
[OH-]-5.8 x 10-4 = basic
[H0] -1.0 x 10-7 = neutral
[OH-] - 4.5 x 10-13 = acidic
Explanation:
Let us note that from the pH scale, a pH of;
0 - 6.9 is acidic
7 is neutral
8 - 14 is basic
But pH= - log [H^+]
pOH = -log [OH^-]
Then;
pH + pOH = 14
Hence;
pH = 14 - pOH
For [H+] -3.5 x 10-5
pH = 4.46 hence it is acidic
For [H+] - 6.7 x 10-9
pH = 8.17 hence it is basic
[OH-]-5.8 x 10-4
pH= 10.76 hence it is basic
[H0] -1.0 x 10-7
pH = 7 hence it is neutral
[OH-] - 4.5 x 10-13
pH = 1.65 hence it is acidic
The shape of the sulfur dioxide molecule, where sulfur is the central atom is
bent.
linear.
trigonal planar.
tetrahedral.
Answer:
bent
Explanation:
The molecular formula of sulfur dioxide is written as SO₂
The molecular geometry of sulfur dioxide can be determined using the Lewis structure.
The Lewis structure shows the distribution of electrons around the atoms of a given compound such as sulfur dioxide (SO₂).
In this compound, sulfur is the central atom with 6 valence electrons.
The sulfur is bonded covalently with two oxygen atoms, each with 6 valence electrons. Oxygen contributes 2 lone pairs while sulfur which is the central atom contributes 1 lone pair of electrons in the bond.
The bond angle between the two oxygen atoms and the central sulfur atom is approximately 120⁰, as a result of the bent shape of the molecular structure.
Methanol has the formula CH3OH. What is the predominant intermolecular force between methanol molecules?
ANSWER:
dispersion forces
dipole forces
ionic bonds
hydrogen bonds
Answer:
hydrogen bonds
Explanation:
similarly CH3OH also has a OH group and H hydrogen thus it will also form h-bonding.
What change would increase the amount of solid solute able to be dissolved in liquid water?
Decreasing rate of stirring
Decreasing surface area
Increasing pressure
Increasing temperature
Answer:
D: Increasing temperature
Explanation:
From collision theory, we know that the more the increase in collisions, the faster the rate of the chemical reaction.
Now, the amount of solid solute in a solvent will change with a corresponding change in temperature. What we mean is that, the higher the temperature increases, the higher the number of collisions between the solvent molecules as well as leading to an increase in the solute particles which will mean an increase in the amount of the solid solute dissolved. The correct answer is option D.
Answer:
Increasing temperature.
Explanation:
Pls pls pls help me
Question 9
2 pts
How many milliliters of 1.0 M HCl needs to be diluted to make 200 mL of a 0.1 M solution?
O 0.2 mL
O 0.02 mL
O 20 mL
2 mL
2 nts
Answer: There are 20 milliliters of 1.0 M HCl is required to be diluted to make 200 mL of a 0.1 M solution.
Explanation:
Given: [tex]M_{1}[/tex] = 1.0 M, [tex]V_{1}[/tex] = ?
[tex]M_{2}[/tex] = 0.1 M, [tex]V_{2}[/tex] = 200 mL
Formula used is as follows.
[tex]M_{1}V_{1} = M_{2}V_{2}[/tex]
Substitute values into the above formula as follows.
[tex]M_{1}V_{1} = M_{2}V_{2}\\1.0 M \times V_{1} = 0.1 M \times 200 mL\\V_{1} = \frac{0.1 M \times 200 mL}{1.0 M}\\= 20 mL[/tex]
Thus, we can conclude that there are 20 milliliters of 1.0 M HCl is required to be diluted to make 200 mL of a 0.1 M solution.
Given the following list of densities, which materials would float in a molten vat of lead provided that they do not themselves melt? Densities (g/mL): lead = 11.4, glass = 2.6, gold = 19.3, charcoal = 0.57, platinum = 21.4.
a. gold and platinum
b. glass and charcoal
c. gold, platinum, glass and coal
d. gold and charcoal
e. None of these
Answer:
b. glass and charcoal
Explanation:
Step 1: Given data
Density of Pb: 11.4 g/mLDensity of Glass: 2.6 g/mLDensity of Au: 19.3 g/mLDensity of charcoal: 0.57 g/mLDensity of platinum: 21.4 g/mLStep 2: Determine which material will float in molten lead
Density is an intrinsic property of matter. Less dense materials float in more dense materials. The materials whose density is lower than that of lead and will therefore float on it are glass and charcoal.
If mass of an empty 9.4 mL pycnometer is 10.3 and the mass of the same pycnometer with an unknown liquid is 20.1. Determine the density of the unknown liquid to the correct number of significant figures in g/mL
Answer:
1.04 g/mL
Explanation:
Applying,
D = (m-m')/V................. Equation 1
Where D = Density of the unknown liquid, m = mass of the pycnometer when filled with unkwon liquid, m' = mass of the empty pycnometer, V = volume of the empty pycnometer
From the question,
Assuming the mass are in grams
Given: m = 20.1 g, m' = 10.3 g, V = 9.4 mL
Substitute these values into equation 1
D = (20.1-10.3)/9.4
D = 9.8/9.4
D = 1.04 g/mL
Suppose a 0.042M aqueous solution of phosphoric acid (H3PO4) is prepared. Calculate the equilibrium molarity of HPO4^−2.
Answer:
2.89x10⁻⁵M = [HPO₄²⁻]
Explanation:
The equilibrium of H3PO4 in water occurs H2PO4-:
H3PO4(aq) + H2O(l) ⇄ H3O⁺(aq) + H2PO4⁻(aq)
pKa = 2.16. And as pKa = -log Ka; Ka = 10^-2.16
Ka = 6.9183x10⁻³ = [H3O⁺] [H2PO4⁻] / [H3PO4]
As both [H3O⁺] and [H2PO4⁻] comes from the same equilibrium,
[H3O⁺]=[H2PO4⁻] :
[H3O⁺] = X
[H2PO4⁻] = X
[H3PO4] = 0.042 - X
Where X is reaction coordinate
Replacing:
6.9183x10⁻³ = [X] [X] / [0.042 - X]
6.9183x10⁻³ = X² / 0.042 - X
2.905686x10⁻⁴ - 6.9183x10⁻³X - X² = 0
Solving for X:
X = -0.02M. False solution. There is no negative concentration.
X = 0.014M. Right solution
[H2PO4⁻] = 0.014M
In the second equilibrium:
H2PO4⁻(aq) + H2O(l) ⇄ HPO4-(aq) + H3O+(aq)
Based on the same principles of the last equilibrium:
pKa2 = 7.21
Ka2 = 6.166x10⁻⁸ = [HPO4-] [H3O+] / [H2PO4⁻]
[HPO4-] = X
[H3O+] = X
[H2PO4⁻] = 0.014M - X
6.166x10⁻⁸ = X² / [0.014M - X]
8.3623x10⁻¹⁰ - 6.166x10⁻⁸X - X² = 0
Solving for X:
X = -0.0000289485. False solution.
X =
2.89x10⁻⁵M = [HPO₄²⁻]3)O que são políticas públicas?
Answer:
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Calculate the mass of Na2S needed if a solution containing 2g of Hg(NO3)2 was added to Na2S solution.
( Hg= 200.59, N= 14, O= 16, Na= 23, S=32)
Answer:
1.433g of HgS are produced
Explanation:
A Solution Containing 2.0 Grams Of Hg(NO3)2 Was Added To A Solution Containing 2.0 Grams Of Na2S. Calculate the mass of the HgS that was formed (it is a precipitate) according to this reaction:
Based on the reaction:
Na2S + Hg(NO3)2 → HgS + 2NaNO3
To solve this question we need to find the moles of each reactant in order to find the limiting reactant. The moles of limiting reactant = moles of HgS:
Moles Na2S -Molar mass: 78.0452 g/mol-
2.0g * (1mol / 78.0452g) = 0.0256 moles Na2S
Moles Hg(NO3)2 -324.7g/mol-
2.0g * (1mol / 324.7g) = 0.006159 moles Hg(NO3)2
As the reaction is 1:1, and moles of Hg(NO3)2 < moles Na2S
The moles of Hg(NO3)2 = Moles HgS = 0.006159 moles
The mass is:
Mass HgS -Molar mass: 232.66g/mol-:
0.006159 moles * (232.66g/mol) =
1.433g of HgS are produced
What is the cell potential of an electrochemical cell that has the half-reactions shown below?
Ag⁺ + e⁻ → Ag
Fe → Fe³⁺ + 3e⁻
Answer:
E°(Ag⁺/Fe°) = 0.836 volt
Explanation:
3Ag⁺ + 3e⁻ => Ag°; E° = +0.800 volt
Fe° => Fe⁺³ + 3e⁻ ; E° = -0.036 volt
_________________________________
Fe°(s) + 3Ag⁺(aq) => Fe⁺³(aq) + 3Ag°(s) ...
E°(Ag⁺/Fe°) = E°(Ag⁺) - E°(Fe°) = 0.800v - ( -0.036v) = 0.836 volt
The number of moles of aluminum that react with 15.7 grams of oxygen according to the equation 4 Al + 3 0 2 - 2 Al 20 3
Answer:
Explanation:
1mol of [tex]O_2=2*16{gr\over{mol}}=32{gr\over{mol}}\\\\15.7gr->15.7gr*{1\over{32{gr\over{mol}}}}=0.491mol~of~O_2[/tex]
as 1mol of molecular oxigen reacts with 4 mol of aluminium
1 mol of O2 -----------------------------> 4 mol of Al
0.491 mol of O2 ------------------------------> x
[tex]x={0.491*4\over{1}}~mol~of~Al=1.9625~mol~of~Al[/tex]
Calculate the mass percent of carbon in the following molecule: Mn3[Mn(CO)4]3
Answer:
21.63 %
Explanation:
The molar mass of Mn₃[Mn(CO)₄]₃ is 665.64 g/mol.
Let's assume we have 1 mol of Mn₃[Mn(CO)₄]₃, if that were the case then we would have 665.64 grams.
There are 12 C moles per Mn₃[Mn(CO)₄]₃, with that in mind we calculate the weight of 12 C moles:
12 mol C * 12 g/mol = 144 gFinally we calculate the mass percent of carbon:
144 g / 665.64 g * 100% = 21.63 %Combustion of 29.26 gg of a compound containing only carbon, hydrogen, and oxygen produces 33.86 gCO2gCO2 and 13.86 gH2OgH2O. Part A What is the empirical formula of the compound
Answer:
C2H4O3
Explanation:
Empirical formula is defined as the simplest whole number ratio of atoms present in a molecule.
To solve this question we need to find the moles of carbon = Moles of CO2, the moles of hydrogen (Using moles of H2O) and the moles of oxygen (Finding the mass of the mass of each atom) as follows:
Moles Carbon -Molar mass CO2: 44.01g/mol-:
33.86g CO2 * (1mol/44.01g) = 0.769 moles CO2 = Moles C * (12g/mol) =
9.23g C
Moles Hydrogen -Molar mass H2O: 18.01g/mol-
13.86g H2O * (1mol/18.01g) = 0.770 moles H2O * (2mol H / 1mol H2O) = 1.54 moles H * (1g/mol) = 1.54g H
Moles Oxygen:
Mass: 29.26g - 9.23g C - 1.54g H = 18.49g O * (1mol/16g) = 1.156 moles O
Dividing each number of moles in the moles of C (Lowe number of moles):
C = 0.769 moles C / 0.769 moles C = 1
H = 1.54 moles H / 0.769 moles C = 2
O = 1.156 moles O / 0.769 moles C = 1.5
As the number must be a whole number each ratio twice:
C = 2
H = 4
O = 3
Empirical formula is:
C2H4O3What is the best explanation for why solid sodium chloride CANNOT conduct electricity and why molten sodium chloride can?
Answer: See explanation
Explanation:
The explanation for why solid sodium chloride can't conduct electricity while molten sodium chloride can is explained below:
Ionic compounds that are in their solid state like sodium chloride have their ions fixed in position. Due to this reason, the able to move, therefore we can say that the solid ionic compounds cannot be able to conduct electricity.
On the other hand, ionic compounds in their molten state, are free to flow unlike when they're in their solid state and therefore we can say that molten sodium chloride can be able to conduct electricity.
Assign oxidation state to each atom in each element ion or compound.
a. Ag
b. Ag+
c. CaF2
d. H2S
e.CO3
f. CrO4
g. Cl2
h. Fe
i. CuCl2
j. CH4
Answer:
a. [tex]Ag^0[/tex]
b. [tex]Ag^{+}[/tex]
c. [tex]Ca^{2+}F_2^-[/tex]
d. [tex]H_2^+S^{2-}[/tex]
e. [tex](C^{4+}O_3^{2-})^{-}[/tex]
f. [tex](Cr^{6+}O_4^{2-})^{2-}[/tex]
g. [tex]Cl_2^0[/tex]
h. [tex]Fe^0[/tex]
i. [tex]Cu^{2+}Cl_2^-[/tex]
j. [tex]C^{4-}H_4^+[/tex]
Explanation:
Hello there!
In this case, according to the concept of charge balance, which tell us that the overall charge is zero for any compound, except ions, it turns out possible to proceed as follows:
a. [tex]Ag^0[/tex]
b. [tex]Ag^{+}[/tex]
c. [tex]Ca^{2+}F_2^-[/tex]
d. [tex]H_2^+S^{2-}[/tex]
e. [tex](C^{4+}O_3^{2-})^{-}[/tex]
f. [tex](Cr^{6+}O_4^{2-})^{2-}[/tex]
g. [tex]Cl_2^0[/tex]
h. [tex]Fe^0[/tex]
i. [tex]Cu^{2+}Cl_2^-[/tex]
j. [tex]C^{4-}H_4^+[/tex]
Keep in mind lonely elements have 0 as their oxidation state.
Regards!
help with the following would be greatly appreciated!
Consider equimolar samples of different ideal gases at the same volume and temperature. Gas A has a higher molar mass than gas B.
1. Compare the pressure
a. A > B
b. A= B
c. A < B
2. Compare the speed.
a. A > B
b. A= B
c. A < B
Answer:
I don't understand the question
Explanation:
1. c
2. c
Answer:
1. b. A = B
2. c. A < B
Explanation:
Consider equimolar samples of different ideal gases at the same volume and temperature. (nA = nB)
Gas A has a higher molar mass than gas B. (MA > MB)
1. We can calculate the pressure using the ideal gas equation.
P = n × R × T / V
Since n, T and V are equal, the pressure of both gases are equal as well.
2. We can calculate the root-mean-square of the velocity using the following expression.
v(rms) = √(3RT/M)
There is an inverse relationship between speed and molar mass. Since A has a higher molar mass, it has a lower speed.
A technical machinist is asked to build a cubical steel tank that will hold "265" L of water. Calculate in meters the smallest possible inside length of the tank. Round your answer to the nearest .
Answer:
0.64 m
Explanation:
Given that;
1L = 0.001 cubic metre
Then;
263 L = 263 L × 0.001 cubic metre/1L
= 0.263 cubic metre
Volume of a cube = l^3
l= 3√V
l= 3√0.263 cubic metre
l= 0.64 m
Increasing the temperature of a chemical reaction usually increases greatly the rate of the reaction. The most iportant reason for this is that increasing the temperature increases: _______.
A) the collision frequency
B) the probability factor
C) the fraction of collisions with energy greater than Bact
D) the energy of activation.
E) the amount of heat released in the reaction
Answer:
the fraction of collisions with energy greater than Eact
Explanation:
The activation energy of a reaction stands as a sort of energy barrier between reactants and products. It is only reactants that possesses energy greater than the activation energy that can be converted from reactants to products.
When the temperature of the system is increased, more particles acquire energy greater than the activation energy. Hence, the fraction of collisions with energy greater than the activation energy increases so the rate of reaction increases likewise.
At 298 K, AHO = -1652 kJ/mol and ASO = 0.097 kJ/(K•mol). What is the Gibbs
free energy of the reaction?
Based on the calculations, the Gibbs's free energy for this chemical reaction is equal to -1,680.906 kJ/mol.
Given the following data:
Enthalpy of reaction (ΔH°) = -1652 kJ/mol.Temperature = 298 K.Entropy of reaction (ΔS°) = 0.097 kJ/mol.What is Gibbs's free energy?Gibbs's free energy simply refers to the quantity of energy that is associated with a particular chemical reaction.
Mathematically, the Gibbs's free energy for this chemical reaction can be calculated by using this formula:
ΔG° = ΔH° - ΔS°
Substituting the given parameters into the formula, we have;
ΔG° = -1652 × 10³ - (298 × 0.097)
ΔG° = -1652 × 10³ - 28.906
ΔG° = -1,680.906 kJ/mol.
Read more on Gibbs's free energy here: brainly.com/question/18752494
#SPJ1
Which equation obeys the law of conservation of
mass?
Answer:2C4H10+2C12+12O2 4CO2+CC14+H20
Consider the following reaction at equilibrium. What effect will decreasing the temperature have on the system? DH=+890kJCO2(g)+2H2O(l)<--> CH4(g)+2O2(g)a) the equilibrium constant will increaseb) the reaction will shift to the left in the direction of the reactantsc) the reaction will shift to the right in the direction of the productsd) no effect will be observed
Answer:
Option B. The reaction will shift to the left in the direction of the reactants.
Explanation:
The equation for the reaction is given below:
CO₂ + 2H₂O <=> CH₄ + O₂
Enthalpy change (ΔH) = +890 KJ
The reaction illustrated by the equation is endothermic reaction since the enthalpy change (ΔH) is positive.
Increasing the temperature of an endothermic reaction will shift the equilibrium position to the right and decrease the temperature will shift the equilibrium position to the left.
Therefore, decreasing the temperature of the system illustrated by the equation above, will shift the reaction to the left in the direction of the reactants.
Thus, option B gives the right answer to the question.
atomaticity of chlorine 1) 2, 2)1, 3) 32 , 4) 4.
Answer:
ATOMICITY OF CHLORINE IS 2Explanation:
Atomicity is defined as the total number of atoms present in a molecule.
Which group has one valence electron
Answer:
Alkaline earth metals or akali metals
A student dropped a piece of silver metal into a solution of HCl(aq). He observed the formation of gas bubbles and collected the gas into another test tube. The student performed a splint test and observed that the splint produced a popping sound when he placed the splint into the test tube of the gas. What can be said about the results of this students experiment?
a. The student performed the splint test incorrectly. He should of observed the splint flare up when the splint was placed in the test tube.
b. The student completed the experiment correctly and there were no errors in the experiment.
c. The experiment was performed incorrectly. Silver doesn't react with HCl. Therefore, the student picked up the wrong metal when conducting the experiment.
d. The student performed the splint test incorrectly. He should of observed the flame being extinguished when the splint was placed in the test tube.
Answer:
The student completed the experiment correctly and there were no errors in the experiment.
Explanation:
When a pea size amount of Ag is dropped into a solution of HCl, the following reaction occurs;
Ag(s) + 2HCl(aq) ----> AgCl(aq) + H2(g)
The gas H2 burns with a pop sound. The gas obtained does not react to litmus. The products of the reaction are expected.
Hence, the experiment was properly conducted and the student completed the experiment correctly and there were no errors in the experiment.
C3H8 is ________
A. unsaturated
B. saturated
How do you predict the geometrical shape of NH3 on VSEPR model
Answer:
NH3 Ammonia
Explanation:
Ammonia has 4 regions of electron density around the central nitrogen atom (3 bonds and one lone pair). These are arranged in a tetrahedral shape. The resulting molecular shape is trigonal pyramidal with H-N-H angles of 106.7°.