Answer: Al₂O₃
Explanation:
25m
45m
Help pls.........
Answer:
45m
Explanation:
I take in oxgyen from the air and send it into your bloodstream. I also remove the carbon dioxide from your body. What system am I?
muscular system
respiratory system
digestive system
skeletal system please help
If 4.50 moles of C2H6 undergoes combustion, how many moles of oxygen would it combust with?
Answer:
First balance the equation
C2H6 + 7/2O2 2CO2 +3H2O
for one mole of C2H6 there are 7/2 mole of O2 required. so for4.50 moles you require 4.50 x 7/2 = 15.75 moles of O2.
Explanation:
What is an ionic solid?
Explanation:
In chemistry, an ionic compound is a chemical compound composed of ions held together by electrostatic forces termed ionic bonding. The compound is neutral overall, but consists of positively charged ions called cations and negatively charged ions called anions.
How many moles is 30 grams of CO2?
Answer:
68
Explanation:
How many atoms are in 57.5 liters of xenon gas at STP
Answer:
1.55 × 10²⁴ atoms Xe
General Formulas and Concepts:
Atomic Structure
Reading a Periodic TableMolesSTP (Standard Conditions for Temperature and Pressure) = 22.4 L per mole at 1 atm, 273 K Avogadro's Number - 6.022 × 10²³ atoms, molecules, formula units, etc.Stoichiometry
Using Dimensional AnalysisExplanation:
Step 1: Define
[Given] 57.5 L Xe at STP
[Solve] atoms Xe
Step 2: Identify Conversions
[STP] 22.4 L = 1 mol
Avogadro's Number
Step 3: Convert
[DA] Set up: [tex]\displaystyle 57.5 \ L \ Xe(\frac{1 \ mol \ Xe}{22.4 \ L \ Xe})(\frac{6.022 \cdot 10^{23} \ atoms \ Xe}{1 \ mol \ Xe})[/tex][DA] Divide/Multiply [Cancel out units]: [tex]\displaystyle 1.54583 \cdot 10^{24} \ atoms \ Xe[/tex]Step 4: Check
Follow sig fig rules and round. We are given 3 sig figs.
1.54583 × 10²⁴ atoms Xe ≈ 1.55 × 10²⁴ atoms Xe
According to the theory of plate tectonics,
which of the following statements is true?
A Earthquakes and volcanoes con change Earth's surface, but the
overall locations of land and ocean do not change over time.
B. Continents have grown, shrunk, and
moved over the course of Earth's history.
C. The ratio of ocean to land on Eorth has been
pretty much the same throughout Earth's history,
Steve and Meg are doing an experiment where they need to make 37 grams of Fe2O3. How many grams of Fe would they need ?
Answer:
25.9g
Explanation:
Molecular mass of Fe₂O₃ = (56 * 2) + (16 * 3)
= 112 + 48 = 160
Let's follow the unitary method now
In 160g Fe₂O₃ , there is 112 g Fe
In 1 g Fe₂O₃ , there is 112 / 160 g Fe
In 37 Fe₂O₃ , we need 112 * 37 / 160
= 25.9 g Fe
Which ecosystem is the least stable?
A. A rain forest
B. A cornfield
C. A savanna
D. A coral reef
In this project, you will develop a model of a chemical reaction that either releases energy or absorbs energy. Whether a reaction releases or absorbs energy depends on the overall difference in the bond energies of the reactants and products. Your model should show the relationships between the parts of the system. These parts are the molecules and atoms that take part in the reaction. The model should also distinguish the reaction system from other systems.
Answer:
that ain't chemistry that's science
A 31.25 mL aliquot of weak base that has a concentration of 0.683 M will be titrated with 0.434 M HCl. Calculate the pH of of the solution upon neutralization of half of the weak base. The Kb of the base is 1.5×10-6.
Answer:
pH = 8.18
Explanation:
The weak base, X, reacts with HCl as follows:
X + HCl → HX⁺ + Cl⁻
Where 1 mole of X with 1 mole of HCl produce 1 mole of HX⁺ (The conjugate acid of the weak base).
Now, using H-H equation for bases:
pOH = pKb + log [XH⁺] / [X]
Where pOH is the pOH of the buffer (pH = 14 -pOH)
pKb is -log Kb = 5.824
And [X] [HX⁺] are the molar concentrations of each specie
Now, at the neutralization of the half of HX⁺, the other half is as X, that means:
[X] = [HX⁺]
And:
pOH = pKb + log [HX⁺] / [X]
pOH = 5.824 + log 1
pOH = 5.824
pH = 14-pOH
pH = 8.18How many moles of argon gas would be present in a 37.0 liter vessel at 45.00 °C at a pressure of 2.50 atm?
Answer:
3.54 mol
Explanation:
Step 1: Given data
Volume (V): 37.0 LTemperature (T): 45.00 °CPressure (P): 2.50 atmStep 2: Convert "T" to Kelvin
We will use the following expression.
K = °C + 273.15
K = 45.00°C + 273.15 = 318.15 K
Step 3: Calculate the number of moles (n) of argon gas
We will use the ideal gas equation.
P × V = n × R × T
n = P × V/R × T
n = 2.50 atm × 37.0 L/(0.0821 atm.L/mol.K) × 318.15 K = 3.54 mol
QUESTION 7
When excess magnesium was reacted with dilute sulphuric acid, the reaction was fast at first but
gradually became slower and finally stopped.
Which of the following describe the reaction?
A.
B.
The magnesium was used up.
The sulphuric acid was used up.
The temperature of the mixture decreased.
The magnesium particles became coated with hydrogen gas.
C.
D.
The reactant present in more amounts is called excess reagent. In the reaction between Mg and sulphuric acid, the reaction gradually stopped due to the consumption of the acid. Thus, option B is correct.
What is an excess reagent?An excess reagent is a chemical reactant present in more quantity than the other substance or reactant in the reaction. They are not totally consumed after the reaction ends, unlike the limiting reagent.
In the reaction, magnesium is the excess reagent while dilute sulphuric acid is a limiting reagent that determines the reaction rate and the product formation. At first, the reaction will be fast but gradually will become slow as all dilute sulphuric acid will be consumed slowing downs and stopping the reaction.
Therefore, dilute sulphuric acid will be used up at the end of the reaction.
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does anyone know thisss???
Write a scientific explanation that answers the following question: Is matter conserved during a
chemical reaction in both closed and open systems?
Claim:
Evidence:
Reasoning:
Answer:
Matter is conserved during all chemical reactions because matter cannot be created or destroyed.
Explanation:
Your friend had an upset stomach caused by indigestion. His mother explained to him
that indigestion is when the contents in the stomach are too acidic. She also told him to
drink soda to settle his stomach. The soda did not help. You tell him that you would not
have expected the soda to help with the indigestion based on what you know about
acids and bases.
ليالي
Baking Soda
Acidic
Neutral
Basic
Explain why soda would not help settle your friend's stomach. In your reponse, be sure
to include:
• a better alternative to drinking soda.
• how each substance above would react with the stomach acid.
• defining characteristics of acids and bases, besides how they react.
Be sure to consider the completeness of your response, supporting details, and accurate
use of terms.
Answer:
because it may cause burn that causes acid to build up which causes you to keep having an upset stomach
An analytical chemist is titrating 111.0 mL of a 0.3700 M solution of aniline (C6H5NH2) with a 0.3500 M solution of HNO3. The pK_b of aniline is 9.37. Calculate the pH of the base solution after the chemist has added 79.1 mL of the HNO_3 solution to it.
Answer:
The answer is "4.31"
Explanation:
aniline millimoles [tex]= 111 \times 0.37 = 41.07[/tex]
added [tex]HNO_3[/tex] millimoles [tex]= 79.1 \times 0.35 = 27.685[/tex]
[tex]\to 41.07 - 27.685 = 13.385[/tex] millimoles aniline left
[tex]\to 27.685[/tex] millimoles salt formed
total volume[tex]= 111 + 79.1 = 190.1\ mL\\\\[/tex]
[tex]\to [aniline] = \frac{13.385}{190.1} = 0.07 \ M\\\\\to [salt] =\frac{ 27.685}{ 190.1} = 0.146\ M\\\\\to pOH = pKb + \frac{\log [salt]}{ [base]}\\\\\to pOH = 9.37 + \frac{\log [0.146]}{[0.07]}\\\\\to pOH = 9.69\\\\\to pH = 14 - 9.69\\\\\to pH = 4.31\\[/tex]
why are ionic compound soluble in water
Answer:
Most ionic compounds are soluble in water. Polar water molecules have a strong attraction for charged ions and the charged ions become solvated as they dissociate into water and ionic compounds are soluble in water.
If 0.8675 g of KHP requires 24.56 mL of an NaOH solution to reach the equivalence
point in the titration, what is the concentration of the NaOH?
Answer:
[tex]M_{base}=0.173M[/tex]
Explanation:
Hello there!
In this case, since the titration of acids like KHP with bases like NaOH are performed in a 1:1 mole ratio, it is possible for us to know that their moles are the same at the equivalence point, and the concentration, volume and moles are related as follows:
[tex]n_{acid}=M_{base}V_{base}[/tex]
Thus, by solving for the volume of the base as NaOH, we obtain:
[tex]M_{base}=\frac{n_{acid}}{V_{base}} \\\\M_{base}=\frac{0.8675g*\frac{1mol}{204.22g} }{0.02456L} \\\\M_{base}=0.173M[/tex]
Best regards!
Which letter in the rock cycle diagram represents metamorphic rock?
A)
A.
B)
B.
)
D.
D)
E.
Answer:
B.Explanation:
Hopes this helps. Mark as brainlest plz!Answer:
b
Explanation:
learned this in science class
Describe in your own words what is an air front is
Answer:
A front is a weather system that is the boundary separating two different types of air. One type of air is usually denser than the other, with different temperatures and different levels of humidity.
Is it posible Count a grain of sand?explain
Answer:
Yes
Explanation:
As long as its a solid, you can count it. It will be hard, but possible.
How many moles is 1.80 * 10^24 molecules of H2O?
Answer:
3.0 molesExplanation:
To find the number of moles in a substance given it's number of entities we use the formula
[tex]n = \frac{N}{L} \\ [/tex]
where n is the number of moles
N is the number of entities
L is the Avogadro's constant which is
6.02 × 10²³ entities
From the question we have
[tex]n = \frac{1.8 \times {10}^{24} }{6.02 \times {10}^{23} } = 2.990.. \\ [/tex]
We have the final answer as
3.0 molesHope this helps you
Give an example of a model used in Earth science. Explain why models are particularly important to this field.
Answer:
Some examples include maps and globes. Conceptual Models - These models serve as a tool to piece together a variety of concepts together so that we can better conceptualize the phenomena under investigation.
Scientific models are used to explain and predict the behaviour of real objects or systems and are used in a variety of scientific disciplines, ranging from physics and chemistry to ecology and the Earth sciences
Which of the solids in the following set should you test to investigate for the effects of ANIONS on pH? Will give brainliest
-KClO
-RbF
-AlBr3
-Rb2SO3
-CrCl3
Answer:
KCIO
Explanation:
the only reason is because I looked online and the meaning for that is potassium hypochlorite my guy so if this is not right then I'm sorry but good luck.
Which is a correct comparison between the modern quantum model and John Dalton’s model of the atom?
Answer:
No comparison => John Dalton did NOT postulate an atomic structure.
Explanation:
Dalton's postulates are based upon generalizations of observable phenomena. Micro structure was not proposed. The atomic structure that's accepted in the scientific community evolved from conclusions of ...
Thompson's raisen pudding model => electrons suspended in a positive matrix
Rutherford's shell model => dense positive nucleus surrounded by an electron cloud. (No fine structure postulated)
Bohr Concentric Ring Model => electrons orbiting a positive nucleus in discrete energy levels much like planets orbiting the sun.
Schrodinger - Dirac Quantum Models => electrons occupying specific orbital energy levels as based upon statistical wave mechanics.
What is the reaction of Dimethylamamine + acetic acid
The limestone used in building the Egyptian pyramids was used because it is _____________
O soft and sticky
O easily melted
O hard and brittle
Answer:
hard and brittle
hope this helps you ☺️☺️
good night take care sweet dream
The equation H2 + O2 -> H2O is unbalanced. When balanced, what is the correct coefficient for O2?
Answer:
The balanced equation would be 2H2 + O2 -> 2H2O
Explanation:
The correct balanced equation is 2H₂ + O₂ → 2H₂O, and the correct coefficient for O₂ is 1.
How to balance a chemical equation?Count the atoms on each side first. Next, alter one of the compounds' coefficient. Third, count the atoms once more, and then repeat steps two and three until the equation is balanced.
In the given equation, hydrogens are already balanced. To balance oxygen, multiple water with 2. Thus, equation becomes:
H₂ + O₂ → 2 H₂O
Now, oxygen is balanced, just the hydrogens got unbalanced. To balance hydrogen, multiply the hydrogen by 2 on the left side.
2 H₂ + O₂ → 2H₂O
Now the chemical equation is balanced, in which the number of oxygen and hydrogen are equal on both sides of the arrow.
Therefore, the coefficient of O₂ is 1.
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The reduction of iron(III) oxide () to pure iron during the first step of steelmaking, ()()() is driven by the high-temperature combustion of coke, a purified form of coal: ()()() Suppose at the temperature of a blast furnace the Gibbs free energies of formation of and are and , respectively. Calculate the maximum mass of pure iron that can be produced by the combustion of of coke. Round your answer to significant digits.
Answer:
hello your question is incomplete attached below is the complete question
answer : To 2 significant digits = 5500 kg
Explanation:
Given
C(s) + O2 (g) ----------> CO2 ( g )
mass of CO2 = 8.9 * 10^6 g
number of moles = 8.9 * 10^6 / 12 = 7.416 * 10 ^5 mol
same amount of moles is needed by O2 hence
attached below is the detailed solution