Answer:
The following parameters:
total mL solution mmol NaOH initial concentration of NaOHExplanation:
The options have been incorrectly arranged in the question statement given here. The three conditions mentioned above are what would be observed to remain the same when this experiment is carried out.
0.0075 mole of calcium trioxocarbonate(IV) is
added to 0.015 mole of a solution of hydrochloric
acid. The volume of gas evolved at stp is?
Answer:
0.0075÷0.015=0.5 not so sure lol
Compute the equilibrium constant for the spontaneous reaction between
Ni2+(aq) and Cd(s).
Express your answer using two significant figures.
Answer:
9.8 × 10^21
Explanation:
Equation of the reaction;
Cd(s) + Ni^2+(aq) ----> Cd^2+(aq) + Ni(s)
E°cell= E°cathode - E°anode
E°cathode= -0.25 V
E°anode = -0.40 V
E°cell= -0.25 - (-0.40)
E°cell = 0.65 V
∆G= -nFE°cell
∆G= -(2 × 96500 × 0.65)
∆G = -125450 J
From;
∆G= -RTlnK
lnK = ∆G/-RT
K= e^∆G/-RT
K= e^-[-(125450/8.314 × 298)]
K= 9.78 × 10^21
Question 6
How many significant figures are there in 31.1100?
Answer:
6 sig figs
Explanation:
sig figs are numbers that are more than 0, but in this case, after the decimal, the 0's at the end count as sig figs as well
There are 6 significant numbers in 31.1100.
If there is no decimal point in the figures then it will be 4 but since there is a decimal point then it is 6 significant figures.
What is the mass, in grams, of a pure iron cube that has a volume of 4.80 cm3?
Answer:
In order to determine the mass of a substance given the volume, we require the density. The density of iron is 7.87 grams/cm³
Density = mass / volume
Mass = density * volume
Mass = 7.87 * 4.8
37.776 grams of iron are present in the cube
The density of the substance represents the relation of the mass to the volume of the substance. The mass of a pure iron cube of density 7.87 grams/cm³ is calculated to be 37.632 grams.
What are mass and density?Mass is the amount of the substance contained that when gets divided by the volume in liters, milliliters or cubic centimeters gives the density of the substance. The mass of the substance can be in grams, kilograms, milligrams, etc.
The mass (m) is the multiplication product of the density (D) and volume (V) of the substance. Mass measures the amount whereas density measures the space occupied by the volume of the substance.
Given,
Density of iron cube (D) = 7.87 grams/cm³
Volume of cube (V) = 4.80 cm³
The formula is given as:
Density = mass ÷ volume
Mass = density × volume
Substituting values from above, the mass in grams of the iron cube is calculated as:
mass = 7.87 grams/cm³ × 4.80 cm³
mass = 37.632 grams
Therefore, the iron cube with a density of 7.87 grams/cm³ has a mass of 37.632 grams.
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Calculate the energy of a photon emitted when an electron in a hydrogen atom undergoes a transition from n=4 to n=1.energy emitted:
Answer:
[tex]\mathbf{\Delta E = 2.042 \times 10^{-19} \ J}[/tex]
Explanation:
Using the Rydberg expression to calculate the change in energy of a photon emitted, we have :
[tex]\Delta E = R ( \dfrac{1}{n_f^2}-\dfrac{1}{n_i^2})[/tex]
where;
R = Rydberg constant = [tex]2.178 \times 10 {-18} \ J[/tex]
[tex]n_f[/tex] = 1 and [tex]n_i[/tex] = 4
replacing our values into equation, we get:
[tex]\Delta E = 2.178 \times 10^{-19} (\dfrac{1}{1^2}-\dfrac{1}{4^2})[/tex]
[tex]\Delta E = 2.178 \times 10^{-19} (\dfrac{1}{1}-\dfrac{1}{16})[/tex]
[tex]\Delta E = 2.178 \times 10^{-19} (\dfrac{15}{16})[/tex]
[tex]\mathbf{\Delta E = 2.042 \times 10^{-19} \ J}[/tex]
A typical adult human body contains approximately 2.500 L of blood plasma. How many grams of blood plasma are in the typical adult human body? The density of blood plasma is 1.03 g/mL.
Answer:
[tex]m=2.575g[/tex]
Explanation:
Hello,
In this case, since the density is defined as the ratio of the mass and volume:
[tex]\rho =\frac{m}{V}[/tex]
We can compute the mass of blood as follows:
[tex]m=\rho *V=1.03g/L*2.500L\\\\m=2.575g[/tex]
Best regards.
A 1.44-g sample of an unknown pure gas occupies a volume of 0.335 L at a pressure of and a temperature of 100.0°C. The unknown gas is ________.
Answer:
Xenon
Explanation:
Step 1: Given data
Mass (m): 1.44 gVolume (V): 0.335 LPressure (P): 1.00 atm (I looked it up)Temperature (T): 100.0°CStep 2: Convert the temperature to Kelvin
K = °C + 273.15 = 100.0°C + 273.15 = 373.2 K
Step 3: Calculate the number of moles (n)
We will use the ideal gas equation.
P × V = n × R × T
n = P × V / R × T
n = 1.00 atm × 0.335 L / (0.0821 atm.L/mol.K) × 373.2 K
n = 0.0109 mol
Step 4: Calculate the molar mass of the gas
M = 1.44 g / 0.0109 mol = 132 g/mol
Step 5: Identify the gas
The gas with a molar mass of about 132 g/mol is xenon.
The gas with a molar mass of 132.11g/mol is Xenon. Hence the unknown gas is Xenon
Using the ideal gas equation
[tex]PV=nRT\\n=\frac{PV}{RT}[/tex]
R is the Boltzmann constant = 8.31
V is the volume of the gas = 0.355L
P is the pressure = 1.00atm
T is the temperature of the gas = 100.0°C = 373K
To get the unknown gas, we need to first get the number of moles of gas:
[tex]n=\frac{1.0\times 0.335}{0.0831 \times 373}\\n=0.0109 moles[/tex]
Get the molar mass of the element;
[tex]n=\frac{m}{M}\\0.0109=\frac{1.44}{M}\\M=\frac{1.44}{0.0109}\\M= 132.11g/mol[/tex]
The gas with a molar mass of 132.11g/mol is Xenon. Hence the unknown gas is Xenon
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Write the condensed structural formula for the major organic product of the following reaction in the presence of light (assume that only one mole of Br2 reacted). Name the reaction mechanism and summarize in words the main steps of the mechanism.
(CH3)4C + Br2
Answer:
(CH3)3CCH2Br
Explanation:
This reaction proceeds by the following mechanism;
First, irradiation with light of appropriate frequency leads to the homolytic fission of the bromine molecule to yield two bromine free radicals. This is the initiation step of the reaction.
The free radical now attacks one of the -CH3 groups in neopentane leading to the formation of (CH3)3CCH2Br.
why ice floats on water is a physical change
Answer:
Ice floats on water because it is less dense than water. When water freezes into its solid form, its molecules are able to form more stable hydrogen bonds locking them into positions. Because the molecules are not moving, they're not able to form as many hydrogen bonds with other water molecules. Ice is a unique substance because it is solid-state — ice — is less dense than its liquid state. Because of this property, ice floats in water. Physical properties are characteristics of a substance. They do not change. Ice floats on water because it is less dense than water. When water freezes into its solid form, its molecules are able to form more stable hydrogen bonds locking them into positions.
Which of the following addresses the economic question of how to produce?
a growing corn instead of potatoes
b. requiring individuals to complete specific types of work
c. producing more capital goods and fewer consumer products
d. selling natural resources to other countries
Answer:
b
Explanation:
The correct answer would be requiring individuals to complete specific types of work.
A question of how to produce deals with the processes of production itself. There are several small processes that eventually aggregate together to lead to the production of goods or services. Some of these small processes will definitely require that individuals within the production unit complete specific types of work.
The option of growing corn instead of potatoes and producing more capital goods and fewer consumer products address what to produce while the option of selling natural resources to other countries has to do with for whom to produce.
Correct option: b
If 27.50 mL of 0.120 M NaOH neutralizes 0.248 g of HAA, what is the molar mass of unknown amino acid
Answer:
75.15 g/mol
Explanation:
First, let us look at the equation of reaction;
[tex]NaOH + HAA --> NaAA + H_2O[/tex]
From the balanced equation of reaction, 1 mole of NaOH is required to completely neutralize 1 mole of HAA.
Recall that: mole = molarity x volume.
Therefore, 27.50 mL, 0.120 M NaOH = 0.0275 x 0.120 = 0.0033 moles
0.0033 mole of NaOH will therefore requires 0.0033 moles of HAA for complete neutralization.
In order to find the molar mass of the unknown amino acid, recall that:
mole = mass/molar mass, hence, molar mass = mass/mole.
Therefore, molar mass of HAA = 0.248/0.0033 = 75.15 g/mol
For the equilibrium PCl5(g)⇌PCl3(g)+Cl2(g), the equilibrium constant Kp is 0.497 at 500K. A gas cylinder at 500K is charged with PCl5(g) at an initial pressure of 1.66atm. Determine the equilibrium pressure of all species at this temperature.
Answer:
[tex]p_{PCl_3}=0.693atm\\\\p_{Cl_2}=0.693atm\\\\p_{PCl_5}=0.967atm[/tex]
Explanation:
Hello,
In this case, for the given reaction, the equilibrium expression is:
[tex]Kp=\frac{p_{PCl_3}p_{Cl_2}}{p_{PCl_5}}[/tex]
But in terms of the reaction extent [tex]x[/tex] can also be written as:
[tex]Kp=\frac{x*x}{p_0-x}[/tex]
Whereas the initial pressure is 1.66 atm. Thus, we write:
[tex]0.497=\frac{x^2}{1.66atm-x}[/tex]
And solving for [tex]x[/tex] we obtain:
[tex]x=0.693atm[/tex]
Therefore, the pressure of each species at equilibrium is:
[tex]p_{PCl_3}=x=0.693atm\\\\p_{Cl_2}=x=0.693atm\\\\p_{PCl_5}=1.66atm-0.693atm=0.967atm[/tex]
Best regards.
For an assignment, Alexis has to write a scientific question. She writes, "How much money should be spent to research brain cancer?" How can she best rewrite this question so it is a scientific question
Answer:
D will brain cancer eventually be curable?
Explanation:
Answer:
Do foods that contain a high amount of fat cause brain cancer?
Explanation:
Do foods that contain a high amount of fat cause brain cancer?
The human body burns glucose for energy according to this chemical reaction: The products of the reaction are carbon dioxide and water . Interestingly, all of the carbon dioxide and much of the water exits the body through the lungs: on every breath, the average person exhales of air, which is typically enriched to and water vapor by volume. In short, when a person loses weight by dieting, the weight that is lost actually departs his body as a gas, every time he exhales. Each kilogram of body fat lost requires exhaling about of carbon dioxide. Calculate how many breaths it takes an average person to "exhale" of fat. Round your answer to the nearest thousand. You'll need to know that the density of is .
Answer:
The average persons requires 75000 breaths to exhale 1.0 Kg of fat
Explanation:
Note: The question is incomplete. The complete question is given below:
"The human body burns glucose (C6H1206) for energy according to this chemical reaction:
C6H1206 + 602----> 6CO2 + 6H20
The products of the reaction are carbon dioxide (CO2) and water (H20). Interestingly, all of the carbon dioxide and much of the water exits the body through the lungs: on every breath, the average person exhales 500 mL of air, which is typically enriched to 4% CO2 and 5% water vapor by volume. In short, when a person loses weight by dieting, the weight that is lost actually departs his body as a gas, every time he exhales. Each kilogram of body fat lost requires exhaling about 3.0 kg of carbon dioxide. Calculate how many breaths it takes an average person to "exhale" 1.00 kg of fat. Round your answer to the nearest thousand. You'll need to know that the density of CO2 is 2.0 kg/m³”.
Volume of air exhaled on average per breath = 500 mL
Volume of CO2 exhaled per breath = 4/100 × 500 = 20 mL
Since, 1000000 mL = 1 m³;
20 mL = 0.00002 m³
3.0 kg of CO2 is exhaled per Kg of fat.
Density of CO2 = 2.0 Kg/m³
Volume = mass/density
Volume of 3.0 Kg CO2 = 3.0/2.0 = 1.5 m³
Number of breaths that will have a volume of 1.5 m³ = 1.5/0.00002 = 75000 breaths.
Q 11.8: Exposure of 2-methyl-2-butene to oxymercuration-demercuration conditions provides which product?
Answer:
Exposure of 2-methyl-2-butene to oxymercuration-demercuration conditions provides 2-methyl-2-butanol.
Explanation:
Please see the attachments below
Draw the Lewis structure for ammonia, NH3. Include lone pairs. In the Lewis structure:_______.
1) Nitrogen has a lone pair of electrons.
2) Nitrogen has three bonding pairs of electrons.
3) Each hydrogen has a bonding pair of electrons.
4) All of the above.
Answer:
4) All of the above.
Explanation:
Hello,
In this case, considering the attached picture wherein the Lewis dot structure is drawn, we realize that the nitrogen has a lone par of electrons, whereas the other three valence electrons are bonded with the three hydrogen atoms in order to obey the octet rule and form three bonding pairs for nitrogen and one bonding pair per hydrogen. Therefore, answer is 4) All of the above.
Regards.
emily measures the temperature of a bowl of water to be 9 degrees celsius. Later she tells her friend that the water has become hot. What is the most likely temperature
of the water
Answer:
The answer is 22 degrees celsius. which is D.
Explanation:
Hot:84-99 F (29-37.5 C) Warm:70-84 F (21-29 C) Cool:55-69 F (13-21 C) Cold: Below 55 F (Below 13 C)
Answer: 22
Explanation: UsaTestPrep
g A sample of chlorine gas occupies 1550 mL at 0.945 atm and 50 C. What is the mass of the sample
Answer:
THE MASS OF THE SAMPLE IS 25.37 g
Explanation:
Using PV = m RT / Mm
P = 0.945 atm
V = 1550 mL = 1.55 L
R = 0.082
T = 50 C
m = unknown
Mm = molar mass = 35.5 * 2 = 71 g/mol
Re-arranging the formula by making m the subject of the equation, we have:
m = PV Mm / RT
m = 0.945 * 1.55 * 71 / 0.082 * 50
m = 103.99725 / 4.1
m = 25.37 g
The mass of the sample is therefore 25.37 g
For the reaction A + 3B → 2C, the rate of disappearance of B given by (Δ[B]/Δt) may also be expressed as
Answer:
[tex]r_B=k[A][B]^3[/tex]
Explanation:
Hello,
In this case, in order to represent the rate disappearance of B, we need to consider the rate law as:
[tex]r_B=k[A][B]^3[/tex]
Whereas k is the rate constant the third power corresponds to B's stoichiometric coefficient as well as the concentrations of A and B because they are involved in the overall rate too.
Regards.
A 1.000 g sample of nitrogen combined with a 0.0720 g sample of hydrogen
to form N2H2. What compound is formed if 1.000 g of nitrogen combines
with 0.2160 g of hydrogen?
N2H6
NH3
NH4+
N4H4
Answer:
The answer is NH3.
Explanation:
The N2H2 (O hydrazine) is formed when from the synthesis of ammonia and hydrogen peroxide.
Or also formed when a 1,000g sample of nitrogen is combined with a 7.2 x10∧-2 sample of hydrogen.
0.2160 of hydrogen is 3 times 7.2 x10∧-2.
It means that the compound would look like:
N2H6.
But in chemistry, if there are divisible numbers in a compound, they must be divided:
NH3.
Calculate the percentrage of neutral form of aspirin that is present in the stomach ph 1.
Answer:
The 99.68% of the aspirin is present in the neutral form
Explanation:
Aspirin, Acetylsalicylic acid, is a weak acid with pKa = 3.5
Using Henderson-Hasselbalch equation:
pH = pKa + log [A⁻] / [HA]
Where [A⁻] is the ionized form and HA the neutral form of the acid
Replacing with a pH of stomach of 1.0:
1.0 = 3.5 + log [A⁻] / [HA]
-2.5 = log [A⁻] / [HA]
3.16x10⁻³ = [A⁻] / [HA] (1)
A 100% of aspirin is = [A⁻] + [HA]
100 = [A⁻] + [HA] (2)
Replacing (2) in (1)
3.16x10⁻³ = 100 - [HA] / [HA]
3.16x10⁻³[HA] = 100 - [HA]
1.00316 [HA] = 100
[HA] = 99.68%
The 99.68% of the aspirin is present in the neutral formDetermine the rate law according to the following data. [H2] (M) [NO] (M) Rate (M/s) Trial 1 0.35 0.30 2.835 x 10-3 Trial 2 0.35 0.60 1.134 x 10-2 Trial 3 0.70 0.60 2.268 x 10-2
Answer:
rate = k [H2O] [NO]²
Explanation:
[H2] (M) [NO] (M) Rate (M/s)
Trial 1 0.35 0.30 2.835 x 10-3
Trial 2 0.35 0.60 1.134 x 10-2
Trial 3 0.70 0.60 2.268 x 10-2
Comparing Trial 1 and 2 , the rate of the reaction increases by a factor of 4 when the concentration of NO was doubled. This means that the reaction is second order with respect to NO
Comparing Trial 2 and Trial 3, the rate of reaction increased by a factor of 2 when the concentration of H2O was doubled. This means that the reaction is first order with respect to H2O
The rate law fr the reaction is given as;
rate = k [H2O] [NO]²
You need to show how the time it takes for a rat to finish a maze changes in different age
groups. What chart or graph should you use?
O Line Graph
Bar Chart
O Pie Chart
O Histogram
O Scatter Plot
I would give brainly
D. The density of cork is approximately 0.24 g/cm^ 3 Convert this density to nanograms per cubic millimeter
Answer:
D
Explanation:
Because jwbahaggagqhhwjwjja
Solid sodium chloride decomposes into chlorine gas and solid sodium . Write a balanced chemical equation for this reaction.
Answer:
2NaCl > Cl2 + 2Na
Explanation:
2 moles of sodium chloride is irreversible to chlorine gas plus 2 moles of solid sodium
Solid sodium chloride decomposes into chlorine gas and solid sodium balanced chemical equation will be 2NaCl → [tex]2 Na^{+} + 2Cl^{-}[/tex].
What is balanced chemical equation?An equation with equal proportions of each kind of atom from both ends of the arrow would be called a balanced chemical reaction. A written symbolic description of a chemical reaction will be known as a chemical equation. The reactant chemical(s) were listed on the left, while the product chemical(s) were listed on the right.
What is chemical equation?Chemical equation is just the presentation of a chemical reaction using symbols and equations for the ingredients.
Solid sodium chloride decomposes into chlorine gas and solid sodium balanced chemical equation will be 2NaCl → [tex]2 Na^{+} + 2Cl^{-}[/tex].
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How many mmoles are in 8.34 mol ?
Answer:
8.34 moles
Explanation:
We are given 8.34 moles.
We need to find moles: 8.34
An important industrial route to extremely pure acetic acid is the reaction of methanol with carbon monoxide: h5sil950 Use bond energies to calculate the heat of reaction.
Answer:
This is an exothermic reaction.
Explanation:
You can calculate the reaction using the calculation below:
ΔH reac= 3(413Kj/mol) +358Kj/mol +467 Kj/mol +1070 kj/mol = 3134 kj/mol
ΔH prod = 3(413 kj/mol) + 347 kj/mol + 358kj/mol +467kj/mol +745 kj/mol = 3156kj/mol
ΔH = 3134 kj/mol - 3156kj/mol = -22 Kj/mol
Negative results indicate an exothermic reaction.
An image of the reaction is attached below.
The heat of the reaction has been -22 kJ/mol. The negative sign has been the indication of the exothermic reaction.
The heat of reaction has been given as the amount of energy absorbed or released by the system to form the products.
The heat of reaction has been given by:
[tex]\Delta H=\Delta H_{reactant}-\Delta H_{product}[/tex]
The heat of reaction has been calculated based on the bond energies. The energy constituent by each bond in the reactant has been the heat of the reactant, and the energy of product has been the heat of product.
The heat of reactant has been given as:The reactant molecules have been [tex]\rm CH_3OH[/tex] and [tex]\rm C\equiv O[/tex].
The bond energy of the reactant has been:
[tex]\Delta H_{reactant}=3\;\times \;\text {C-H}\;+\;\text{C-O + O-H}+\;\text C\equiv \text O\\ \Delta H_{reactant}=3\;\times \;413\;+\;358+467+1070\;\text{kJ/mol}\\ \Delta H_{reactant}=3134\;\text{kJ/mol}[/tex]
The heat of reactant has been 3134 kJ/mol.
The heat of product has been given as:The product molecule has been [tex]\rm CH_3COOH[/tex]
The bond energy of the product has been:
[tex]\Delta H_{product}=3\;\times \;\text {C-H}\;+\;\text{C-O + O-H +\;C-C}+\;\text C=\text O\\\Delta H_{reactant}=3\;\times \;413\;+\;358+467+\;347\;+\;745\;\text{kJ/mol}\\\Delta H_{reactant}=3156\;\text{kJ/mol}[/tex]
The heat of product has been 3156 kJ/mol.
The heat of reaction has been given as:
[tex]\Delta H=\Delta H_{reactant}-\Delta H_{product}\\ \Delta H=3134-3156\;\text{kJ/mol}\\ \Delta H=-22\;\rm kJ/mol[/tex]
The heat of the reaction has been -22 kJ/mol. The negative sign has been the indication of the exothermic reaction.
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Which answer choices correctly describe why the number of known elements more then doubled by 1861
Answer:
- Communication between scientists increased.
- Technological advancements were made.
Explanation:
The complete question is
Which answer choices correctly describe why the number of known elements more than doubled by 1861?
Select all that apply.
- Metalworkers began using new metals.
- Communication between scientists increased.
- The American Civil War started.
- Technological advancements were made.
Technological advancement allowed more elements to be properly analysed and classified, and knowledge sharing between scientist by means of communication made it possible for the known number of elements to double by 1861
Indicate the ionic species that predominates at pH 4, 8, and 11 for (a) ammonia and (b) phosphoric acid.
A piece of metal with a mass of 150 g is placed in a 50 mL graduated cylinder. The water level rises from 20 mL to 45mL. What is the volume of the metal? and what is the density of the metal
Answer:
volume = 15
density = 10
Explanation:
mass = 150 grams
volume = 45 - 20 = 15
density = mass / volume
density = 150 / 15 = 10