Marine chemist exam in the mass percent composition of manganese sulfide compound from ocean floor he determined that 60.2% of this compound is sulfur determine the mole ratio between manganese and sulfur
Explanation:
Let the mass of the compound be 100g.
There are 60.2g of sulfur.
Moles of sulfur
= 60.2g / (32.07g/mol) = 1.877mol
There are 100g - 60.2g
= 39.8g of manganese.
Moles of manganese
= 39.8g / (54.94g/mol) = 0.724mol
Mole ratio of manganese to sulfur
= 0.724mol : 1.877mol = 1 : 2.5.
A sample of iron is put into a calorimeter (see sketch at right) that contains of water. The iron sample starts off at and the temperature of the water starts off at . When the temperature of the water stops changing it's . The pressure remains constant at . Calculate the specific heat capacity of iron according to this experiment. Be sure your answer is rounded to the correct number of significant digits.
Answer:
Therefore, the specific heat capacity of the iron is 0.567J/g.°C.
Note: The question is incomplete. The complete question is given as follows:
A 59.1 g sample of iron is put into a calorimeter (see sketch attached) that contains 100.0 g of water. The iron sample starts off at 85.0 °C and the temperature of the water starts off at 23.0 °C. When the temperature of the water stops changing it's 27.6 °C. The pressure remains constant at 1 atm.
Calculate the specific heat capacity of iron according to this experiment. Be sure your answer is rounded to the correct number of significant digits
Explanation:
Using the formula of heat, Q = mc∆T
where Q = heat energy (Joules, J), m = mass of a substance (g)
c = specific heat capacity (J/g∙°C), ∆T = change in temperature (°C)
When the hot iron is placed in the water, the temperature of the iron and water attains equilibrium when the temperature stops changing at 27.6 °C. Since it is assumed that heat exchange occurs only between the iron metal and water; Heat lost by Iron = Heat gained by water
mass of iron = 59.1 g, c = ?, Tinitial = 85.0 °C, Tfinal = 27.6 °C
∆T = 85.0 °C - 27.6 °C = 57.4 °C
mass of water = 100.0 g, c = 4.184 J/g∙°C, Tinitial = 23.0 °C, Tfinal = 27.6 °C
∆T = 27.6°C - 23.0°C = 4.6 °C
Substituting the values above in the equation; Heat lost by Iron = Heat gained by water
59.1 g * c * 57.4 °C = 100.0 g * 4.184 J/g.°C * 4.6 °C
c = 0.567 J/g.°C
Therefore, the specific heat capacity of the iron is 0.567 J/g.°C.
You want to determine the concentration of a phosphoric acid (H3PO4) solution using a standardized 0.0995 M NaOH solution. 10.00 mL of the H3PO4 solution needed to be titrated with 22.85 mL of the standardized 0.0995M NaOH solution to reach the equivalence point. What is the concentration of the H3PO4 solution
Answer:
Explanation:
H₃PO₄ + 3NaOH = Na₃PO₄ + 3 H₂O.
1 mole 3 mole
22.85 mL of the standardized 0.0995M NaOH solution will contain
.0995 x .02285 moles of NaOH
= 22.7357 x 10⁻⁴ moles of NaOH
3 moles of NaOH reacts with 1 mole of H₃PO₄
22.7357 x 10⁻⁴ moles of NaOH reacts with 1 x 22.7357 x 10⁻⁴ / 3 mole of H₃PO₄
= 7.5785 x 10⁻⁴ moles of H₃PO₄
7.5785 x 10⁻⁴ moles of H₃PO₄ is contained in 10 mL or 10⁻² L
molarity of H₃PO₄ solution = 7.5785 x 10⁻⁴ / 10⁻²
= 7.58 x 10⁻² M
= .0758 M .
US
What is the percent of H in
NH3?
(H = 1.008 amu, N = 14.01 amu)
[?]%
Answer:
17.6
Explanation:
Answer is explained above
which toxic gas is released in incomplete combustion?
Answer:
Incomplete combustion produces carbon monoxide (CO), a toxic gas.
Explanation:
Combustion is the rapid chemical reaction of oxygen in the air or direct oxygen, which is defined as oxidizer, with the different elements that make up the fuel (mainly carbon (C) and hydrogen (H)). These chemical reactions release energy producing local increases in temperature, which causes a flow of heat to the outside.
In other words, on the one hand you have the fuel, which is the substance that oxidizes and that you can find in a solid, liquid or gaseous state and which is made up mostly of carbon and hydrogen.
The oxidizer, for its part, is the substance that oxidizes the fuel, and it is generally the oxygen found in the air.
Certain amounts of oxidizer and fuel must come into contact for combustion to occur.
Incomplete combustion occurs when part of the fuel does not fully react. Incomplete combustion produces carbon monoxide (CO), a toxic gas.
In table below, there are descriptions of an experiment on samples of three different chemical compounds. Decide whether the compound is ionic or molecular, if you can. If there is not enough information to decide, choose can't decide in the third column.
Compound Description Ionic or molecular?
can't decide
1 Compound 1 is a hard grayish-white solid. A small 250. mg
sample of it is put into a quartz tube and heated strongly.
It starts to melt at 1055. °C.
2 Compound 2 is a hard grayish-white solid. When tapped
gently with a small hammer, a sample fractures into
fragments and a whitish powder. The powder is soluble in
water, and when 15 g are dissolved in 100 mL of water,
the solution conducts electricity well.
3 Compound 3 is a soft waxy white solid that can be easily
shaped and molded by hand. When the flame of an ordinary
laboratory burner is held about 10 cm away from the solid,
it rapidly and extensively melts into a clear liquid.
Answer:
Compound 1- ionic solid
Compound 2- can't really decide
Compound 3- molecular solid
Explanation:
An ionic solid has a very high melting point. It is hard but not brittle. It's solution or melt but not it's solid conducts electricity. Compound 1 is an ionic solid.
We can't really decide on compound 2 since it is brittle yet it's solution conducts electricity.
Lastly, compound 3 is a molecular solid since it has a low melting point.
Answer:
Compound 1- ionic solid
Compound 2- can't really decide
Compound 3- molecular solid
Explanation:
I need help on these questions!
Answer:
See explanation
Explanation:
Given that;
E = hc/λ
h = 6.63 * 10^-34 Js
c = 3 * 10^8 ms-1
λ = ?
E = 3.978 * 10^-19 J
λ = hc/E
λ = 6.63 * 10^-34 * 3 * 10^8 /3.978 * 10^-19
λ = 19.89 * 10^-26/3.978 * 10^-19
λ = 5 * 10^-7 m The colour is green
2. E = hc/λ
E= 6.63 * 10^-34 * 3 * 10^8 /1000 * 10^-9
E = 1.989 * 10^-19 J
But
E = hf
f = E/h
f = 1.989 * 10^-19/6.63 * 10^-34
f = 3 * 10^14 Hz The radiation is infrared
3. E = hc/λ
λ= hc/E
λ= 6.63 * 10^-34 * 3 * 10^8 /2.0 * 10^-14
λ= 995 * 10^-14 m This is gamma radiation
4. E = hc/λ
E=6.63 * 10^-34 * 3 * 10^8 /620 * 10^-9
E = 3.2 * 10^-19 J
5. E = hf
E= 6.63 * 10^-34 * 2 * 10^17
E = 1326 * 10^-19 J
E = hc/λ
λ= hc/E
λ= 6.63 * 10^-34 * 3 * 10^8 /1326 * 10^-19 = 15 * 10^-9
This is ultraviolet radiation
Need help asap
1. All nonmetals (except hydrogen) have 8 valence electrons?
True or False
2. The N^-3 ion is classified as a(n) ____ and has ____.
A. anion, 8 valence electrons
B. cation, 8 valence electrons
C. anion, 15 valence electrons
D. anion, 3 valence electrons
3. If two nonmetals react to form a compound and have very different _____ they form ____ bonds. If there is a small difference, then they form ____ bonds.
A. ionization energy; covalent; nonpolar ionic
B. electronegativity; nonpolar covalent; polar covalent.
C. ionization energy, ionic, nonpolar covalent
D. electronegativity, polar covalent, nonpolar covalent.
Answer:
1: false
2: B
Explanation:
I do not know the 3rd one
26. A Grignard's reagent may be made by
reacting magnesium with which of the
following compound ?
(A)
Methyl amine
(B) Diethyl ether
(C
)
Ethyl iodide
(D)
Ethyl alcohol
1)
If I have 45 liters of helium in a balloon at 25°C and increase the
temperature of the balloon to 55° C, what will the new volume of the
balloon be?
Answer:
52.8 Liters
Explanation:
Gay-Lussacs law states that P1/T1 = P2/T2
if:
P1 = 45T1 (in Kelvins) = 25 + 273.1 =298.1P2= ?T2 = 55 + 273.1 = 328.1then:
45/298.1 = P2/328.1
P2 = 52.8
The new volume of the balloon is 52.8 Liters this can be calculated by using gas laws.
Charles law:Charles law states the volume occupied by a fixed amount of gas is directly proportional to its absolute temperature. It is given by
V₁/T₁ = V₂/T₂
What information do we have?
V₁ = 45 L
T₁ = 25 + 273.1 =298.1 K
T₂ = 55 + 273.1 = 328.1 K
To find:
V₂= ?
On substituting the values:
45/298.1 = V₂/328.1
V₂ = 52.8 L
Thus, the volume of the balloon is 52.8 liters.
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A 50.0mL flask filled with a solution of hydrogen peroxide has a total mass of 88.5 g. The mass of the flask is 16.5 g. The density of the hydrogen peroxide solution is
Answer:
1.44 g/mL
Explanation:
total mass is mass of the flask plus mass of the solution
TM = Flask + H2O2
88.5 = 16.5 + x
x = 72.0 gram
density = mass/volume
H2O2 density = 72/50
= 1.44 g/mL
Zack and Frankie were planning a game of flashlight tag on both Friday and Saturday night.
Answer:
oKaY?!
Explanation:
Construct an explanation using Newton's Laws of Motion to describe the effects of balanced and unbalanced forces on the motion of an object.
Answer:
The manner in which objects will move is determined by the answer to this question. Unbalanced forces will cause objects to change their state of motion
Explanation:
Since these two forces are of equal magnitude and in opposite directions, they balance each other.
Answer:
balance force are those force whose resultant force is zero and unbalanced force are those whose resultant are non zero
Based on the molecular formula, determine whether each of the following is an alkane, alkene, or alkyne. (Assume that the hydrocarbons are noncyclical and there is no more than one multiple bond.)
a. C3H6
b. C6H12
c. H8H18
d. C7H12
Answer:
C₃H₆ is an alkene
C₆H₁₂ is an alkene
C₈H₁₈ is an alkane
C₇H₁₂ is an alkyne
Explanation:
To determine which of the compound is alkane, alkene, or alkyne,we shall use the general formula of alkane, alkene, and alkyne. This is illustrated below:
General formula for alkane => CₙH₂ₙ₊₂
General formula for alkene => CₙH₂ₙ
General formula for alkyne => CₙH₂ₙ₋₂
For C₃H₆:
n = 3
Alkane => CₙH₂ₙ₊₂ => C₃H₂₍₃₎₊₂ => C₃H₈
Alkene => CₙH₂ₙ => C₃H₂₍₃₎ => C₃H₆
Alkyne => CₙH₂ₙ₋₂ => C₃H₂₍₃₎₋₂ => C₃H₄
Thus, C₃H₆ is an alkene
For C₆H₁₂:
n = 6
Alkane => CₙH₂ₙ₊₂ => C₆H₂₍₆₎₊₂ =>C₆H₁₄
Alkene => CₙH₂ₙ => C₆H₂₍₆₎ => C₆H₁₂
Alkyne => CₙH₂ₙ₋₂ => C₆H₂₍₆₎₋₂ => C₆H₁₀
Thus, C₆H₁₂ is an alkene
For C₈H₁₈:
n = 8
Alkane => CₙH₂ₙ₊₂ => C₈H₂₍₈₎₊₂ => C₈H₁₈
Alkene => CₙH₂ₙ => C₈H₂₍₈₎ => C₈H₁₆
Alkyne => CₙH₂ₙ₋₂ => C₈H₂₍₈₎₋₂ => C₈H₁₄
Thus, C₈H₁₈ is an alkane.
For C₇H₁₂:
n = 7
Alkane => CₙH₂ₙ₊₂ => C₇H₂₍₇₎₊₂ => C₇H₁₆
Alkene => CₙH₂ₙ => C₇H₂₍₇₎ => C₇H₁₄
Alkyne => CₙH₂ₙ₋₂ => C₇H₂₍₇₎₋₂ => C₇H₁₂
Thus, C₇H₁₂ is an alkyne.
SUMMARY:
C₃H₆ is an alkene
C₆H₁₂ is an alkene
C₈H₁₈ is an alkane
C₇H₁₂ is an alkyne
Directions: Select the words that make the sentence a true statement Below is a food web showing the flow of energy through a marine ecosystem marine mammals tuna fish aquida craba zooplankton amall fishes doad animal material 3 phytoplankton In this ecosystem are considered predators and are their prey
Answer: in this ecosystem tuna fish are considered predators and small fishes are their prey.
Explanation: This is just an easy smart guess why? because the Tuna fish(predator) eat the small fishes(prey) as if what it looks like in the chart.
Im not sure about this question but i hope this helps
Answer:
in this ecosystem tuna fish are considered predators and small fishes are their prey.
Explanation:
What is the relationship between the mass of the boat and the mass of the displaced
liquid?
The mass of the boat is equal to the mass of the liquid which is displaced by placing the boat in the liquid.
What is Archimedes' Principle?
Archimedes' Principle states that the buoyant force of the object is equal to the weight of the water which is displaced by the boat. If the weight of the water that is displaced by the boat is less than that of the weight of the boat, then in this case the boat sinks. Archimedes' principle or the buoyant force is very useful for the calculation of the volume of an object that does not have a regular shape.
The mass of the displaced liquid is always equal to the volume of the liquid multiplied by the density of the fluid. When a boat is placed in the water, the volume of displaced water is equal to the mass of the boat which is placed in it.
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fluorine is more reactive than chlorine.
Answer:
yes because of fluorine has higher electronegativity
atom ,molecule, proton neutron electron, elements/compounds from SMALLEST to the BIGGEST.
Answer:
Electron,Protons/Neutrons,Atom,Molecule
Explanation:
Why is it easier to switch to solar and wind energy as compared to other alternative energy sources? Select all that apply.
A. They are more cost-effective.
B. They require large, easily obtainable parcels of land.
C. They can be produced easily in areas with geothermal activity.
D. The land can be used for other purposes while supplying energy.
Answer:C. They can be produced easily in areas with geothermal activity.
D. The land can be used for other purposes while supplying energy.
Explanation:
Both c and d are correct
It is easier to switch to solar and wind energy as compared to other alternative energy sources because they can be produced easily in areas with geothermal activity and can be used for other purposes while supplying energy.
What is solar energy?Solar energy is any type of energy generated by the sun. Solar energy can be harnessed directly or indirectly for human use.
Generating energy that produces no greenhouse gas emissions from fossil fuels and reduces some types of air pollution.
Diversifying energy supply and reducing dependence on imported fuels. Creating economic development and jobs in manufacturing, installation, and more.
Hence, options C and D are correct.
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The transfer of heat by electromagnetic waves *
O Conduction
O Convection
O Radiation
Answer:
radiation
Explanation:
hope this helps!
Pressure is often defined as
Answer:
Pressure is often defined as a measure of force applied on an area, or over a unit area.
Explanation:
Based on the number of valence electrons indicated by its location in the periodic table ,which elements behavior would you predict to be closest to that of potassium (k)
Answer:
Na sodium or Rb rubidium
Explanation:
Because Na is present in first group all members of group 1 have 1 electron in valence shell and show similar properties.
Which macromolecules break apart by hydrolysis?
Answer:
Dehydration synthesis reactions build molecules up and generally require energy, while hydrolysis reactions break molecules down and generally release energy. Carbohydrates, proteins, and nucleic acids are built up and broken down via these types of reactions, although the monomers involved are different in each case.
Explanation:
Crude oil has many applications once it has been distilled at a refinery. According to the diagram, what process is used to distill crude oil into its various components to use energy distribution?
A) separation by density
B) separation by boiling points
C) separation by the porosity of the components
D) separation by the organic content or each component
Answer:
B) separation by boiling points
Explanation:
According to the diagram depicted, crude oil is separated into its different units using boiling points.
The boiling points of a compound is the temperature at which it begins to boil. The process of fractional distillation is used in the oil industry to separate crude oil into its components. When the boiling point of a oil fraction is reached, it becomes vaporized and rises within the columnhow long does crushed candy dissolve in a warm water
Answer:
Because of reaction between solid and liquid
Answer:
shouldn't take that long i would say from 30 to 40 minutes bc its melting in warm water its turning from a solid to a liquid.
Explanation:
Copper metal reacts with silver nitrate to produce silver metal and copper (II) nitrate.
the correct equation for this reaction is:
A: Cu + SiN—> Si + Cu2N
B: 2Cu + AgNO3–> Ag +
Cu(NO3)2
C: Cu + 2 AgNO3–> Ag + Cu(NO3)2
D:Cu + AgNO3–> Ag + CuNO3
Answer:
Cu + 2AgNO₃ → 2Ag + Cu(NO₃)₂
Explanation:
The reactants are:
Copper metal = Cu
Silver nitrate = AgNO₃
The products are:
Silver metal = Ag
Copper (II) nitrate = Cu(NO₃)₂
So, the reaction equation is given as;
Cu + 2AgNO₃ → 2Ag + Cu(NO₃)₂
This is a single displacement reaction
The substance krypton has the following properties normal melting point 115.9 K normal boiling point: 119.8 K triple point: 0.72 atm. 115.8 K critical point: 54.3 atm. 209.4 K A sample of krypton at a pressure of 1.00 atm and a temperature of 149.2 K is cooled at constant pressure to a temperature of 107.8 K Which of the following are true?
a) The final state of the substance is a solid
b) One or more phase changes will occur
c) The final state of the substance is a liquid
d) The sample is initially a gas
e) The solid initially present will vaporize.
Answer:
B. One or more phase change occur
C. the final state of substance is liquid
D. the sample initially gas
Explanation:
The pressure p = 1.00 atm
The temperature t = 149.2K
The temperature > 119.8K
119.8K being the normal boiling point.
This shows that the krypton is a gas
After it has cooled the pressure = 1.00 atm
The temperature T dropped to 107.8K
T < 115.9K
The melting point has been put as 115.9K
This is a liquid. The final state of the substance is a liquid. Since the temperature is less than the melting point and the pressure is 1.00 atm
Naturally occurring silicon consists of three isotopes with the following isotopic masses and abundances. Isotope Isotopic mass (u) Abundance (%) 2828 Si 27.976926532727.9769265327 92.229792.2297 2929 Si 28.9764947228.97649472 4.68324.6832 3030 Si 29.9737702229.97377022 3.08723.0872 Calculate the average atomic mass of naturally occurring silicon to at least four significant figures.
The question is incomplete, the complete question is;
Silicon has three naturally occurring isotopes with thefollowing masses and natural abundances:
Isotope Mass ({\rm amu}) Abundance (%)
{\rm Si}-28 27.9769 92.2
{\rm Si}-29 28.9765 4.67
{\rm Si}-30 29.9737 3.10
Calculate the atomic mass of silicon.
Answer:
28.09 amu (to four significant figures)
Explanation:
Given that;
Isotope Mass Abundance (%)
Si-28 27.9769 92.2
Si-29 28.9765 4.67
Si-30 29.9737 3.10
So we now have;
Relative atomic mass of silicon;
(27.9769 × 0.9218) + (28.9765 × 0.0471) + (29.9738 × 0.0312)
25.789 + 1.365 + 0.9351 = 28.09 amu (to four significant figures)
How many electrons must nitrogen gain to become like it’s closest noble gas, Neon?
Answer:
3
Explanation:
Classify each of the observed changes according to whether or not they are likely to represent evidence that a chemical reaction is occurring when performing an experiment.
May be evidence of a chemical reaction Not evidence of a chemical reaction
a solution color becoming less intense
due to dilution
bubbles (sas formation) changes in color
precipitation
explosion or fire
Answer Bank
a solid liquifying change in temperature solution colors mixing
Answer:
a solution color becoming less intense due to dilution- is not an evidence of a chemical reaction
bubbles (gas formation) - evidence of a chemical reaction
explosion or fire - evidence of a chemical reaction
changes in color- evidence of a chemical reaction
precipitation- evidence of a chemical reaction
changes in temperature - evidence of a chemical reaction
a solid liquifying - is not an evidence of a chemical reaction
solution colors mixing - is not an evidence of a chemical reaction
Explanation:
A chemical change is not easily reversible and yields new substances. It is often accompanied by a loss or gain of heat.
In the answer section, i have shown some evidences that lead us to conclude that a chemical reaction has taken place. The occurrence of a chemical change often goes with the formation of new substances as earlier stated and any of these signs may accompany the process.
For instance, when a metal is dropped in dilute acid solution, bubble of hydrogen gas indicates that a chemical reaction has taken place.