Answer:
They want to know how long it has been since it last erupted.
Explanation:
Scientists study a volcano's history to try to predict when it will next erupt. They also want to know the time span between its previous eruptions
1. Oxygen was discovered by Joseph Priestley in 1774 when he heated mercury (II) oxide, HgO, to decompose it to form its constituent elements. How many moles of mercury (II) oxide are needed to produce 125 g of oxygen?
Given:
Unknown:
Mole ratio:
Solution:
2. In a blast furnace, iron (III) oxide is used to produce iron by the following (unbalanced) reaction:
Fe2O3(s) + CO(g) Fe(s) + CO2(g)
If 4000 g of Fe2O3 is available to react, how many moles of CO are needed?
Given:
Unknown:
Mole ratio:
Solution:
Final answer:
ugh pls help:(
Answer:
1. 7.81 moles HgO
2. n = mass/molar mass = (4000 g)/(159.69 g/mol) = 25.05 mol.
Explanation:
How many moles of mercury (II) oxide are needed to produce 125 g of oxygen?
2HgO ==> 2Hg + O2
125 g O2 x 1 mol O2/32 g x 2 mol HgO / mol O2 = 7.81 moles HgO
------------------------------------------------------------------------------------------------------------
If 4000 g of Fe2O3 is available to react, how many moles of CO are needed?
The no. of moles of CO are needed = 75.15 mol.
Fe₂O₃ + 3CO → 2Fe + 3CO₂,
It is clear that 1 mol of Fe₂O₃ reacts with 3 mol of CO to produce 2 mol of Fe and 3 mol of CO₂.
If 4.00 kg Fe₂O₃ are available to react, how many moles of CO are needed?
We need to calculate the no. of moles of 4.00 kg Fe₂O₃:
n = mass/molar mass = (4000 g)/(159.69 g/mol) = 25.05 mol.
Using cross multiplication:
1 mol of Fe₂O₃ need → 3 mol of CO to react completely, from stichiometry.
25.05 mol of Fe₂O₃ need → ??? mol of CO to react completely.
The no. of moles of CO are needed = (3 mol)(25.05 mol)/(1 mol) = 75.15 mol.
Identify the functional groups present in each molecule.
A 19-carbon compound is composed of one five-membered ring and three six-membered rings.
Carbon 3 is double bonded to an oxygen and attached to carbon 2 and carbon 4.
Carbon 17 is attached to an oxygen, which is attached to a hydrogen.
i. hydroxyl group
ii. carboxyl group
iii. carbonyl group
A central carbon is attached to an amine, two hydrogens, and a carbon that is double bonded to an oxygen and single bonded to an oxygen attached to a hydrogen.
i. amino group
ii. carboxyl group
iii. amide group
Answer:
Carbon 3 is double bonded to an oxygen and attached to carbon 2 and carbon 4. :
Answer: Carbonyl group ( Ketone or aldehyde)
Carbon 17 is attached to an oxygen, which is attached to a hydrogen. :
Answer: Carboxyl group (Carboxylic acid)
A central carbon is attached to an amine, two hydrogens, and a carbon that is double bonded to an oxygen and single bonded to an oxygen attached to a hydrogen. :
Answer: Amide group
An amide group contains both amine and carboxyl
[tex].[/tex]
Plss answer!!! I need help fast
Answer:
2 Na atoms
1 C atom
3 O atoms
gram formula weight = 105.99 g
hope this helped :)
Explanation:
→ Na
# of Atoms - 2
→ C
# of Atoms - 1
→ O
# of Atoms - 3
→ gram formula weight (g) : 105.99 g
A compound's properties are different than the properties of the elements that make it up.
A)True
B)False
What are acids ? Will they harm skin
Hydrochloric acid can cause damage if it comes into contact with your lungs, eyes, stomach, or skin. If hydrochloric acid comes into contact with your skin, it can cause: chemical burns. scarring.
How many moles of Magnesium(Mg) are
in 2.46 x 10^28 atoms of Magnesium?
so 2.46 X 10^28 contains (2.46 X 10^28)/(6.02 X 10^23) =
(2.46 X 10 X 10^27)/ (6.02 x(10^23) = (24.6/6.02) X 10^ (27-23)=
4.09 X 10^4 = 40,900
Answer:
4.09 X 10^4 = 40,900 moles
Explanation:
How many moles of Magnesium(Mg) are
in 2.46 x 10^28 atoms of Magnesium?
PLEASE LEARN THIS FUNDAMENTAL RULE OF CHEMISTRY...1 MOLE OF ANYTHING CONTAINS AVOGADROS NUMBER OF PARTICLES}
6.02 X 10^23.09
so 2.46 X 10^28 contains in moles(2.46 X 10^28)/(6.02 X 10^23) =
(2.46 X 10 X 10^27)/ (6.02 x(10^23) = (24.6/6.02) X 10^ (27-23)=
4.09 X 10^4 = 40,900 moles
1. Boiling
2. Opposite
3. Freezing
4. The particles lose energy to the surroundings
5. Condensation
6. B
7. E
8. D
9. A
10. C
That is my question don't liy
Explain why the nucleus of an atom is positively charged but the overall charge of an atom is neutral
Answer:
sorry
Explanation:
i'm not a chemistry student
but let me try
it is because the neutron of an atom is -
why the proton and electron is +and- (positive and negative)
so + and - = 0
The vapor pressure of a liquid at a given temperature is measured when the rate of evaporation of a liquid becomes
Answer:
the liquid becomes equal to the rate of condensation
Explanation:
ive come across this question before! and i think its right! :D
The vapor pressure of a liquid at a provided temperature is measured when the rate of evaporation of a liquid evolves equally to the rate of condensation.
What is Evaporation?
Evaporation is the procedure by which water transforms from a liquid to a gas or vapor.
Evaporation is the primary route that water moves from the liquid circumstances around into the water cycle as atmospheric water vapor.
When a molecule around the surface absorbs adequate energy to overwhelm the vapor pressure, it will exit and join the surrounding air as a gas.
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Which temperatures originally represented the fixed points
Celsius temperature scale?
Answer:Since 1743 the Celsius scale has been based on 0 °C for the freezing point of water and 100 °C for the boiling point of water at 1 atm pressure. Prior to 1743 the values were reversed (i.e. the boiling point was 0 degrees and the freezing point was 100 degrees).
Explanation: i no it
Butanoic acid + 2 propanol
Answer:
propyl butanoate
Explanation:
which of the materials above are mixtures
Answer:
water and vinegar
:salad
Explanation:
There is two kind of mixture the heterogeneous and homogeneous mixture.Which water and vinegar is the homogeneous and the salad is heterogeneous mixture based on my example above.
What happens when the compound CaCl2 forms?
Explanation:
Calcium gives valence electrons to both chlorine atoms so that they have a full outer shell.
what is the total amount of energy absorbed by the substance as it completely changes from a solid at 40 degrees to a gas at 200 degrees
Answer:
I don't know the answer sorry man
Sodium, Na, is a metallic element.
Explain, with the aid of a labelled diagram, what is meant by the term metallic bonding.
Answer:
metallic bonding is the bond form between two or more metal elements or between metal element and the other group elements
______help in increasing rates of reactions
Answer:
Catalysts help in increasing rates of reactions
Answer:
тємρєяαтυяє
Explanation:
Temperature. Usually reactions speed up with increasing temperature.
Use the pie section above to answer this question.
The pie section shows Earth's composition from the center to the surface. Section IV is most likely composed of
solid iron.
basalt rock.
liquid iron.
granite rock.
Answer:
can you show me a picture of the pie chart?
Explanation:
if i dont see the pie chart then this question isn't possible to answer
Que son Moléculas neutras
Answer:
Una molecula en que hay igual numero de cargas positivas y negativas y los electrones estan distribuidos de modo que no hay regiones con carga parcial(o sea una molecula no polar). Esto ocurre cuand los atomos tienen mas o menos igual electronegatividad para atraer los electrones.
Explanation:
what is the bonding of hydrogen?
Answer:
A hydrogen bond is a primarily electrostatic force of attraction between a hydrogen atom which is covalently bound to a more electronegative atom or group, and another electronegative atom bearing a lone pair of electrons..
(refer the image)
Explanation:
brainliest plz
WHAT IS THE COLOR OF METHYL ORANGE
1. YELLOW
2. PINK
3. ORANGE
Answer:
3.Orange it literally say's it methyl ORANGE
Explanation:
Brainliest plz
Answer:
Other indicators
Indicator Acidic Alkaline
Methyl orange Red Yellow
Phenolphthalein Colourless Pink
A force of 500 N acts over an area of 10 m2. Use the
formula to calculate the pressure.
Answer:
50Pa
Explanation:
pressure= force/area
= 500N/10m2
= 50Pa
96 POINTS
1. An atom of platinum has a mass number of 195 and an atomic number of 78. How many protons and neutrons are in this atom? – Calculate your answer and please note that work must be shown to earn credit.
neutrons=117
protons=78
Answer:
Platinum has mass number 195.
The atomic number of platinum =78
so the number of protons is 78.
By using simple formulas
we can find out that how many neutrons and protons are present in an atom of platinum-195.
Mass number = neutrons + protons
195=neutrons + 78
neutrons=195-78=117
so the number of neutrons is 117.
6. What is the atomic mass of Hafnium if out of every 200 atoms, 10 have mass 176.00 g/mol, 38 have mass
177.00 g/mol, 54 have mass 178.00 g/mol, 28 have mass 179.00 g/mol, and 70 have mass 180.00 g/mol?
Answer:
fg
Explanation:
what type of energy is the sum of kinetic and potetinal energy in an object that is used to do work
Answer:
mechanical energy
Explanation:
The change in internal energy for the combustion of cyclohexanol (C6H12O) is -890.7 Kcal per mole. A .708 g sample of cyclohexanol undergoes complete combustion in a bomb calorimeter that has a heat capacity of 2.70 Kcal per degree C. What is the final temperature of the water in the calorimeter if the initial water temperature is 27C?
The final temperature in the calorimeter, with a heat capacity of 2.70 kcal/°C, internal energy for the combustion of cyclohexanol (C₆H₁₂O) of -890.7 kcal/mol and initial temperature of 27°C, is 29.33 °C.
We can find the final temperature of the water in the calorimeter with the following equation:
[tex]\Delta E = -C\Delta T = -C(T_{f} - T_{i})[/tex] (1)
Where:
ΔE: is the change in internal energy for the combustion of C₆H₁₂O = -890.7 Kcal/mol
C: is the heat capacity of the calorimeter = 2.70 Kcal/°C
[tex]T_{f}[/tex]: is the final temperature =?
[tex]T_{i}[/tex]: is the initial temperature = 27 °C
By solving equation (1) for [tex]T_{f}[/tex], we have:
[tex] T_{f} = -\frac{\Delta E}{C} + T_{i} [/tex]
[tex]T_{f} = -\frac{-890.7 \frac{kcal}{mol\: C_{6}H_{12}O}*\frac{1 mol \: C_{6}H_{12}O}{100.158 g \: C_{6}H_{12}O}*0.708 g \: C_{6}H_{12}O}{2.70 kcal/^{\circ}C} + 27 ^{\circ}C = 29.33 ^{\circ}C[/tex]
Therefore, the final temperature of the water is 29.33 °C.
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I hope it helps you!
what happens to the matter in water as it evaporates
Answer:
It changes from a liquid to a gas. I hope this helps you! :D
lights of different frequencies make up
Answer:
Light waves come in a continuous variety of sizes, frequencies and energies, a continuum known as the electromagnetic spectrum. Once Maxwell introduced the concept of electromagnetic waves, everything clicked into place.
Explanation:
Hope this helps:)
~Kisame'sAbs
What molecule is this?
Answer:
O2C
Explanation:
Answer:
Carbon Monoxide (CO) is a colorless, odorless, tasteless, toxic gas that has the molecular formula CO. The molecule consists of a carbon atom that is triply bonded to an oxygen atom. ... The linear molecule consists of a carbon atom that is doubly bonded to two oxygen atoms, O=C=O
Explanation:
3. Ethanol has a density of 0.800 g/mL.
a. What is the mass of 225 mL of ethanol?
Since the ethanol has a density of 0.800 g/mL, the mass of the ethanol is 180 grams.
Given the following data:
Volume of ethanol = 225 mLDensity of lead ball = 0.800 g/mL.To find the mass of the ethanol;
Density can be defined as mass all over the volume of an object.
Mathematically, the density of a substance is given by the formula;
[tex]Density = \frac{Mass}{Volume}[/tex]
Making mass the subject of formula, we have;
[tex]Mass = Density \times Volume[/tex]
Substituting the given parameters into the formula, we have;
Mass of ethanol = 180 grams.
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In the preparation of a certain alkyl halide, 10 g of sodium bromide (NaBr), 10 mL distilled water (H20), and 9 mL 3-methyl-1-butanol (C5H120) were mixed in the round-bottomed flask and allowed to cool for 2 -3 minutes. Then while swirling the flask, 10 mL sulfuric acid (H2SO4) was slowly added to the flask and the mixture was refluxed and later distilled. The mass of the pure product obtained was 6.48 g. Sodium hydrogen carbonate (NaHCO3) was used to remove impurities. (Density of 3-methyl-1-butanol is 0.810 g/mL). The percentage yield will be?
Percentage yield shows the amount of reactants converted into products. The percentage yield of the reaction is 51.7%.
The equation of the reaction is sown in the image attached. The reaction is 1:1 as we can see.
Number of moles of NaBr = 10 g/103 g/mol = 0.097 moles
We can obtain the mass of 3-methyl-1-butanol from its density.
Mass = density × volume
Density of 3-methyl-1-butanol = 0.810 g/mL
Volume of 3-methyl-1-butanol = 9 mL
Mass of 3-methyl-1-butanol = 0.810 g/mL × 9 mL
Mass of 3-methyl-1-butanol = 7.29 g
Number of moles of 3-methyl-1-butanol = mass/molar mass = 7.29 g/88 g/mol = 0.083 moles
Since the reaction is 1:1 then the limiting reagent is 3-methyl-1-butanol
Mass of product 1-bromo-3-methylbutane = number of moles × molar mass
Molar mass of 1-bromo-3-methylbutane = 151 g/mol
Mass of product 1-bromo-3-methylbutane = 0.083 moles × 151 g/mol
= 12.53 g
Recall that % yield = actual yield/theoretical yield × 100
Actual yield of product = 6.48 g
Theoretical yield = 12.53 g
% yield = 6.48 g/12.53 g × 100
% yield = 51.7%
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