Answer:
C. Physical Change
Explanation:
Peeling a banana is not changing the banana's structure, it's still the same banana, but it looks different, which is a chemical change! Hope I helped!
All the iron in a 2.000 g tablet was dissolved in an acidic solution and converted to Fe2+. This was then titrated with KMnO4. The titration required 27.50 cm3 of 0.100 mol dm-3 KMnO4. Calculate the total mass of iron in the tablet and its percentage by mass.
Answer:
0.768g of Fe are in the tablet = 38.4% by mass of Fe in the tablet
Explanation:
The balanced redox equation of Fe²⁺ with KMnO₄ in acidic medium is:
5Fe²⁺ + MnO₄⁻ + 8H⁺ → 5Fe³⁺ + Mn²⁺ + 4H₂O
Where 5 moles of Fe²⁺ react per mole of KMnO₄
The moles required of KMnO₄ are:
27.50cm³ * (1dm³ / 1000cm³) = 0.0275dm³ * (0.100mol / dm³) = 0.00275mol KMnO₄
Moles of Fe²⁺ are:
0.00275mol KMnO₄ * (5 moles Fe²⁺ / 1mol KMnO₄) = 0.01375moles of Fe²⁺
In grams (Molar mass Fe: 55.845g/mol):
0.01375moles of Fe²⁺ * (55.845g/mol) =
0.768g of Fe are in the tabletAnd percentage is:
0.768g Fe / 2.000g * 100 =
38.4% by mass of Fe in the tabletHow much heat do you need to raise the temperature of 100 g of aluminum from 30°C to 150°C?
Answer:
Heat energy can be calculated by using the specific heat of a substance multiplying it to the mass of the sample and the
change in temperature. It is expressed as:
Energy = mCAT
Energy = 100 (0.90) (150 - 30)
Energy = 10800 J
How do the percent compositions for C3H6 and C4H7 compare?
A. They are the same
B. C4H8 has a higher percentage of carbon than C3H6.
C. C4H8 has a higher percentage of hydrogen than C3H6.
D. none of the above
A. They are the same
Further explanationGiven
C3H6 and C4H8
Required
The percent compositions
Solution
C₃H₆(MW = 42 g/mol)%C = 3.12/42 x 100% = 85.71%
%H = 6.1/42 x 1005 = 14.29%
C₄H₈(MW=56 g/mol)
%C = 4.12/56 x 100% = 85.71%
%H = 8.1/56 x 100%=14.29%
So they are the same, because mol ratio of C and H in both compounds is the same, 1: 2
A control. during a experiment
A scientific control is an experiment or observation designed to minimize the effects of variables other than the independent variable. This increases the reliability of the results, often through a comparison between control measurements and the other measurements.
A student sets up the following equation to convert a measurement.
(The ? stands for a number the student is
going to calculate.)
Fill in the missing part of this equation.
Note: your answer should be in the form of one or more fractions multiplied together.
gcm
3 kg.m
-2.9 x 10
0x0
.
X Х
5
Answer:
9 . this was not able the first one. it has to go on, I will not sure about
2 NaOH (s) + CO2(g) → Na2CO3 (s) + H20 (I)
How many grams of water can be produced with 1.85 moles of NaOH
16.7 g H₂O
General Formulas and Concepts:Math
Pre-Algebra
Order of Operations: BPEMDAS
Brackets Parenthesis Exponents Multiplication Division Addition Subtraction Left to RightChemistry
Stoichiometry
Reading a Periodic TableUsing Dimensional AnalysisExplanation:Step 1: Define
[RxN - Balanced] 2NaOH (s) + CO₂ (g) → Na₂CO₃ (s) + H₂O (l)
[Given] 1.85 mol NaOH
Step 2: Identify Conversions
[RxN] 2 mol NaOH → 1 mol H₂O
Molar Mass of H - 1.01 g/mol
Molar Mass of O - 16.00 g/mol
Molar Mass of H₂O - 2(1.01) + 16.00 = 18.02 g/mol
Step 3: Stoichiometry
Set up: [tex]\displaystyle 1.85 \ mol \ NaOH(\frac{1 \ mol \ H_2O}{2 \ mol \ NaOH})(\frac{18.02 \ g \ H_2O}{1 \ mol \ H_2O})[/tex]Multiply/Divide: [tex]\displaystyle 16.6685 \ g \ H_2O[/tex]Step 4: Check
Follow sig fig rules and round. We are given 3 sig figs.
16.6685 g H₂O ≈ 16.7 g H₂O
How many lead atoms in Pb(OH) 4 ?
4 in hydrogen 4 in oxygen
Explanation:
hope this helps
what is the difference between the number of electrons in an atom of selenium, Se and the number of electrons in an atom of aluminum, Al?
Answer:
Well, electrons can be converted into a atomic number so if SE atomic number is 34 that means it has 34 electrons. AI has a atomic number of 13 meaning it has 13 electrons. So the difference is that SE has more electrons then AI.
When performing a multiplication or division calculation, significant figures in the calculated result are dictated by the _____ of the measured numbers.
The calculated result should have ______ the measured number in the calculation with the fewest _______.
Answer:
fewest; the same significant figures with; measured numbers.
Explanation:
Without mincing words let us dive straight into the solution to the above question. In order to be able to use the significant figures properly one must know the rules attached to it uses. This is so, because they contributes to the precision of measurements.
When performing multiplication or division calculation, the number of significant figures in the answer[result] will be determined by the one with the smallest number of significant figure in the problem. Therefore, if we have 6.56 which is three[3] significant figures and 1.2 which is two[2] significant figures, then the number of significant figures will be two[2].
6.56 × 1.2= 7.872 = 7.9[ to 2 significant figures].
As a heavy metal ball rolls down a hill, it goes faster and faster. Which statement is true?
The ball's potential energy is transferring into kinetic energy
Brainly if correct? Thanks!
Answer:
A
Explanation:
The balls potential energy is changing to kinetic energy
How many electrons does a single hydrogen gain or lose in the following reaction?
H2 + O2 - H20
Answer:
One electron per single hydrogen atom.
Explanation:
Hello!
In this case, given the reaction:
[tex]H_2+O_2\rightarrow H_2O[/tex]
Whereas we can identify the following half-reaction for hydrogen:
[tex]H_2^0\rightarrow H_2^+[/tex]
Whereas we see that each single hydrogen atom gains one electron in order to go from 0 to +1, which is also related to an oxidation half-reaction.
Best regards!
dicyclopropyl ether?
Answer:
??????????????????
Explanation:
)??
a sample of solid is decomposed and found to contain 6.52g of potassium, 4.34 g of chromium and 5.34 of oxygen, what is the empirical formula of the compound? help asap
Answer:
K₂CrO₅
Explanation:
The empirical formula is the simplest formula of a compound. To find the empirical formula, we follow the procedure below:
Elements Potassium Chromium Oxygen
Mass 6.52 4.34 5.34
Molar mass 39 60 16
Number of moles 6.52/39 4.34/60 5.34/16
0.167 0.072 0.333
Divide through by
the smallest 0.167/0.072 0.072/0.072 0.333/0.072
2.3 1 4.6
2 1 5
Empirical formula K₂CrO₅
Calculate the mass of beryllium (Be) needed to completely react with 18.9 g nitrogen gas (N2) to produce Bez N2, which is the only product of the reaction.
A. 6.19
B. 12.29
C. 18.29
D. 36.69
Answer:
C = 18.29 g
Explanation:
Given data:
Mass of beryllium needed = ?
Mass of nitrogen = 18.9 g
Solution:
Chemical equation:
3Be + N₂ → Be₃N₂
now we will calculate the number of moles of nitrogen:
Number of moles = mass/molar mass
Number of moles = 18.9 g/ 28 g/mol
Number of moles = 0.675 mol
Now we will compare the moles of nitrogen and Be from balance chemical equation.
N₂ : Be
1 : 3
0.675 : 3/1×0.675 = 2.03 mol
Number of moles of Be needed are 2.03 mol.
Mass of Beryllium:
Mass = number of moles × molar mass
Mass = 2.03 mol × 9.01 g/mol
Mass = 18.29 g
My question my question
H2O as an oxidant only
Further explanationGiven
Reaction
2 Na + 2 H2O → 2 NaOH + H2
Required
The function of water in the equation
Solution
Water : oxidizing agent
Na : reducing agent
Na⁰ → Na⁺ (oxidation)
H⁺- → H⁰ (reduction)
Acids and bases according to Bronsted-Lowry
Acid = donor (donor) proton (H⁺ ion)
Base = proton (receiver) acceptor (H⁺ ion)
If water is acting as an acid it should only give 1 H +, so that becomes:
H₂O (l) ⇔ OH⁻ (aq) not H₂
The density of toluene (C7H8) is 0.867 g/mL, and the density of thiophene (C4H4S) is 1.065 g/mL. A solution is made by dissolving 8.10 g of thiophene in 250.0 mL of toluene.
(a) Calculate the mole fraction of thiophene in the solution.
(b) Calculate the molality of thiophene in the solution.
(c) Assuming that the volumes of the solute and solvent are additive, what is the molarity of thiophene in the solution?
Considering the solution of mole fraction, molality and molarity, you obtain that:
(a) the mole fraction of thiophene in the solution is 0.039.
(b) the molality of thiophene in the solution 0.4429 [tex]\frac{moles}{kg}[/tex].
(c) the molarity of thiophene in the solution is 0.373[tex]\frac{moles}{L}[/tex].
You know that:
Density toluene (C₇H₈)= 0.867 [tex]\frac{g}{mL}[/tex]Density thiophene (C₄H₄S)= 1.065 [tex]\frac{g}{mL}[/tex] Volume of toluene (C₇H₈)= 250 mL= 0.250 L (being 1000 mL= 1 L)Mass of thiophene (C₄H₄S)= 8.10 grams(a) Mole fractionThe molar fraction is a way of measuring the concentration that expresses the proportion in which a substance is found with respect to the total moles of the solution.
Being the molar mass of each compound equals to:
Toluene (C₇H₈)= 92 [tex]\frac{g}{mol}[/tex]Thiophene (C₄H₄S)= 84 [tex]\frac{g}{mol}[/tex]the number of moles of each compound can be calculated as:
Toluene (C₇H₈)= [tex]250 mLx\frac{0.867 grams}{1 mL} x \frac{1 mole}{92 grams}[/tex]= 2.35 molesThiophene (C₄H₄S)= [tex]8.10 gramsx\frac{1 mole}{84 grams}[/tex]= 0.096 molesThe total moles is obtained from the addition of the moles of the solute (C₄H₄S) and the solvent (C₇H₈):
total moles = moles C₄H₄S + moles C₇H₈ = 0.096 moles + 2.35 moles = 2.45 moles
Then, the mole fraction of thiophene in the solution can be calculated as:
[tex]mole fraction of thiophene=\frac{0.096 moles}{2.45 moles}[/tex]
Solving:
mole fraction of thiophene= 0.039
Finally, the mole fraction of thiophene in the solution is 0.039.
(b) MolalityMolality is the ratio of the number of moles of any dissolved solute to kilograms of solvent.
The Molality of a solution is determined by the expression:
[tex]Molality=\frac{number of moles of solute}{kilograms of solvent}[/tex]
In this case, you know:
number of moles of solute (C₄H₄S)= 0.096 moles Mass of solvent = [tex]250 mLx\frac{0.867 grams}{1 mL}[/tex] = 216.75 g = 0.21675 kg (being 1000 g=1 kg)Replacing:
[tex]Molality C_{4} H_{4}S =\frac{0.096 moles}{0.21675 kg}[/tex]
molality C₄H₄S= 0.4429 [tex]\frac{moles}{kg}[/tex]
Finally, the molality of thiophene in the solution 0.4429 [tex]\frac{moles}{kg}[/tex].
(c) MolarityMolarity is the number of moles of solute that are dissolved in a certain volume and is determined by the following expression:
[tex]Molarity=\frac{number of moles of solute}{volume}[/tex]
Assuming that the volumes of solute and solvent are additive, you can add the volume of C₄H₄S and C₇H₈.
But first, you need yo know the volume of C₄H₄S, which can be calculated from the mass and density:
[tex]Volume C_{4} H_{4}S =8.10 grams\frac{1 mL}{1.065 grams}[/tex]= 7.606 mL= 0.007606 L
Then, the total volume of the solution is calculated as:
total volume of the solution= volume C₇H₈ + volume C₄H₄S
total volume of the solution= 0.250 L + 0.007606 L = 0.257606 L
So, the molarity of thiophene in the solution can be calculated as:
[tex]Molarity C_{4} H_{4} S=\frac{number of moles of C_{4} H_{4} S}{totalvolumeof the solution}[/tex]
Replacing:
[tex]Molarity C_{4} H_{4} S=\frac{0.096 moles}{0.257606 L}[/tex]
Solving:
Molarity C₄H₄S= 0.373 [tex]\frac{moles}{L}[/tex]
Finally, the molarity of thiophene in the solution is 0.373[tex]\frac{moles}{L}[/tex].
In summary, you get:
(a) the mole fraction of thiophene in the solution is 0.039.
(b) the molality of thiophene in the solution 0.4429 [tex]\frac{moles}{kg}[/tex].
(c) the molarity of thiophene in the solution is 0.373[tex]\frac{moles}{L}[/tex].
Learn more about
density: brainly.com/question/952755?referrer=searchResults brainly.com/question/1462554?referrer=searchResults mole fraction: brainly.com/question/14434096?referrer=searchResults brainly.com/question/10095502?referrer=searchResults molality brainly.com/question/20366625?referrer=searchResults brainly.com/question/4580605?referrer=searchResults molarity with this example: brainly.com/question/15406534?referrer=searchResultsthe gravitational force between two objects depends on the distance between the objects and each object?
Answer:
Gravitational force between two objects depends on: a. The weight of the objects c. The mass of each object b. The distance between the objects d. Both b and c Please select the best answer from the choices provided A B C D
✓d
Weigh out the appropriate amount of HEPES sodium salt required to prepare 100 mL of a HEPES buffer that has pH 7.50 and is 90 mM in HEPES. FW for the HEPES sodium salt is 260.31. Transfer to a 150 mL beaker. Flowchart: Calculate the amount of HEPES sodium salt required to make the buffer.
Answer:
2.343 g of HEPES sodium salt is needed.
Explanation:
So, from the question above we have the following parameters which is going to help in solving this particular question.
The number of moles = 90mM, the pH = 7.50, FW for the HEPES sodium salt = 260.31, and the volume of HEPES sodium salt required = 100mL.
Therefore, the amount of HEPES sodium salt required to make the buffer = 260.31 × 9 × 0.001 = 2.343 grams of HEPES sodium salt is needed in 10mL.
according to the bohr model of an atom, what happens when an electron moves from the second energy level to the third energy level and then back to the second energy level?
Answer:
when the atom moves to the third energy level, its energy increases. However, when it goes back to the second energy level its overall energy decreases.
Explanation:
the smallest (or innermost) energy level has the least amount of energy and the largest (or outer most) level needs the most amount of energy. In order for the electron to move from one level to the other, it would need to match the energy of that level.
A solution was diluted 1/40, and the final concentration was 20%. What was the original concentration?
The original concentration : 800%
Further explanationGiven
Diluted 1/40
Final concentration 20%
Required
The original concentration
Solution
Dilution is the process of adding solvent to get a more dilute solution.
The moles(n) before and after dilution are the same.
Can be formulated :
n₁ = n₂
M₁.V₁ = M₂.V₂
diluted 1/40(dilution factor)⇒ V₁/V₂=1/40⇒V₂/V₁=40
M₂ = 0.2(20%)
Input the value for M₁ :
M₁=M₂ x (V₂/V₁)
M₁ = 0.2 x 40
M₂ = 8(800%)
=
Which of the below elements are part of a group? Feel free to use the periodic table.
A. H, He, O, C
B. Be, Mg, Ca, Sr
C. Li, Be, C, O
D. H, Li, Na, Mg
Answer:
B. Be, Mg, Ca, Sr
Explanation:
Be, Mg, Ca, Sr are parts of the alkaline Earth metal family/group. So they are the second most reactive elements following behind alkali metals. Furthermore, Be, Mg, Ca, Sr all have 2 valence electrons that lose them to form cations. They have low melting points, low boiling points, can conduct electricity, have high malleability and ductility.
Hope it helped!
How many grams of Fe3+ are present in 2.56 grams of iron(III) iodide?
Answer:
436.55841 grams.
Explanation:
The molecular formula for Iron(III) Iodide is FeI3. The SI base unit for amount of substance is the mole. 1 mole is equal to 1 moles Iron(III) Iodide, or 436.55841 grams.
You use the 1 / 436.55841 conversion rate. This is different for each element, according to the stoichiometry tables. Iron(II) oxide would be 2/3 of the 1/436.55841 conversion rate, that is, multiplying the fraction to denominator.
How can your knowledge of acids and bases
help you approach this problem to keep your soil
viable?
HELP NOW
Answer:
How can we make use of acids or bases to remove heavy metals from soils? We can remove heavy metals from soil by adding acid and catching the solution that drains through. Acids can react with metals turning metalic compounds which can be dissolved by water and washed away. Improve crop yields?
Explanation:
How did the grandmother show her gratitude towards her granddaughter
answer this and in end please tell me how to mark answer as brainliest I will mark your answers as brainliest
Answer:
vgffffgggggvghvxgyfdgubvhumigrrdghg
. Predict the possible products for the following reaction and include
molecular, complete ionic, and net ionic equations.
NA2SO4 (aq) +γ (BrO3)2 (aq) --->
Answer:
Introduction
As a diligent student of chemistry, you will likely encounter tons of reactions that occur in aqueous solution (perhaps you are already drowning in them!). When ions are involved in a reaction, the equation for the reaction can be written with various levels of detail. Depending on which part of the reaction you are interested in, you might write a molecular, complete ionic, or net ionic equation.
Definitions of molecular, complete ionic, and net ionic equations
A molecular equation is sometimes simply called a balanced equation. In a molecular equation, any ionic compounds or acids are represented as neutral compounds using their chemical formulas. The state of each substance is indicated in parentheses after the formula. [Huh?]
Let's consider the reaction that occurs between \text{AgNO}_3AgNO
3
start text, A, g, N, O, end text, start subscript, 3, end subscript and \text{NaCl}NaClstart text, N, a, C, l, end text. When aqueous solutions of \text{AgNO}_3AgNO
3
start text, A, g, N, O, end text, start subscript, 3, end subscript and \text{NaCl}NaClstart text, N, a, C, l, end text are mixed, solid \text{AgCl}AgClstart text, A, g, C, l, end text and aqueous \text{NaNO}_3NaNO
3
start text, N, a, N, O, end text, start subscript, 3, end subscript are formed. Using this information, we can write a balanced molecular equation for the reaction:
\text{AgNO}_3(aq) + \text{NaCl}(aq) \rightarrow \text{AgCl}(s) + \text{NaNO}_3(aq)AgNO
3
(aq)+NaCl(aq)→AgCl(s)+NaNO
3
(aq)start text, A, g, N, O, end text, start subscript, 3, end subscript, left parenthesis, a, q, right parenthesis, plus, start text, N, a, C, l, end text, left parenthesis, a, q, right parenthesis, right arrow, start text, A, g, C, l, end text, left parenthesis, s, right parenthesis, plus, start text, N, a, N, O, end text, start subscript, 3, end subscript, left parenthesis, a, q, right parenthesis
[What kind of reaction is this?]
If we could zoom in on the contents of the reaction beaker, though, we wouldn't find actual molecules of \text{AgNO}_3AgNO
3
start text, A, g, N, O, end text, start subscript, 3, end subscript, \text{NaCl}NaClstart text, N, a, C, l, end text, or \text{NaNO}_3NaNO
3
start text, N, a, N, O, end text, start subscript, 3, end subscript. Since \text{AgNO}_3AgNO
3
start text, A, g, N, O, end text, start subscript, 3, end subscript, \text{NaCl}NaClstart text, N, a, C, l, end text, and \text{NaNO}_3NaNO
3
start text, N, a, N, O, end text, start subscript, 3, end subscript are soluble ionic compounds, they dissociate into their constituent ions in water. For example, \text{NaCl}NaClstart text, N, a, C, l, end text dissociates into one ion of \text{Na}^+Na
+
start text, N, a, end text, start superscript, plus, end superscript for every ion of \text{Cl}^-Cl
−
start text, C, l, end text, start superscript, minus, end superscript; these ions are stabilized by ion-dipole interactions with the surrounding water molecules. [I don't get it!]
Image of crystalline sodium chloride next to image of chloride and sodium ions dissociated in water. Each chloride ion is interacting with multiple water molecules through the positive dipole of the water, and each sodium ion is interacting with water molecules through the negative dipole of the water.
Image of crystalline sodium chloride next to image of chloride and sodium ions dissociated in water. Each chloride ion is interacting with multiple water molecules through the positive dipole of the water, and each sodium ion is interacting with water molecules through the negative dipole of the water.
Sodium chloride dissociates into sodium and chloride ions in water, and these ions become solvated by the highly polar water molecules. Image credit: "Salts: Figure 1" by OpenStax Anatomy and Physiology, CC-BY-NC-SA 4.0.
From the molecular formula, we can rewrite the soluble ionic compounds as dissociated ions to get the complete ionic equation:
\text{Ag}^+(aq) + \blueD{{\text{NO}_3}^-(aq)} + \maroonD{\text{Na}^+(aq)} + \text{Cl}^-(aq) \rightarrow \text{AgCl}(s) + \maroonD{\text{Na}^+(aq)} + \blueD{{\text{NO}_3}^- (aq)}Ag
+
(aq)+NO
3
−
(aq)+Na
+
(aq)+Cl
−
(aq)→AgCl(s)+Na
+
(aq)+NO
3
−
−
(aq)
+
Na
+
(aq)
+Cl
−
(aq)→AgCl(s)+
Na
+
(aq)
+
NO
3
−
(aq)
How many grams of Fe will be produced if 705.0g of H20 are produced?
Fe3O4 + 4H2
-->
3 Fe + 4H2O
2265 g Fe₃O₄
General Formulas and Concepts:Math
Pre-Algebra
Order of Operations: BPEMDAS
Brackets Parenthesis Exponents Multiplication Division Addition Subtraction Left to RightChemistry
Atomic Structure
Reading a Periodic TableStoichiometry
Using Dimensional AnalysisExplanation:Step 1: Define
[RxN - Balanced] Fe₃O₄ + 4H₂ → 3Fe + 4H₂O
[Given] 705.0 g H₂O
Step 2: Identify Conversions
[RxN] 4 mol H₂O → 1 mol Fe₃O₄
Molar Mass of H - 1.01 g/mol
Molar Mass of O - 16.00 g/mol
Molar Mass of Fe - 55.85 g/mol
Molar Mass of H₂O - 2(1.01) + 16.00 = 18.02 g/mol
Molar Mass of Fe₃O₄ - 3(55.85) + 4(16.00) = 231.55 g/mol
Step 3: Convert
Set up stoich: [tex]\displaystyle 705.0 \ g \ H_2O(\frac{1 \ mol \ H_2O}{18.02 \ g \ H_2O})(\frac{1 \ mol \ Fe_3O_4}{4 \ mol \ H_2O})(\frac{231.55 \ g \ Fe_3O_4}{1 \ mol \ Fe_3O_4})[/tex]Multiply/Divide/Cancel units: [tex]\displaystyle 2264.74 \ g \ Fe_3O_4[/tex]Step 4: Check
Follow sig fig rules and round. We are given 4 sig figs.
2264.74 g Fe₃O₄ ≈ 2265 g Fe₃O₄
please help me please help me
which mineral is composed of calcium and fluorine?
Answer:
Fluorite
What is Fluorite? Fluorite is an important industrial mineral composed of calcium and fluorine (CaF2). It is used in a wide variety of chemical, metallurgical, and ceramic processes
How many moles are in the following:
7.36 x 1024 of free Oxygen atoms
Answer: 12.2 moles
Explanation:
7.36x10^24/6.02214076x10^23 = 12.2 moles of free oxygen atoms
Which of the statements about liquids and gases are true?
Both liquids and gases have a definite volume.
O The particles in liquids and gases can move past one another
freely
Both liquids and gases have a definite shape.
Neither liquids nor gases have a definite shape.
Which of the statements about liquids and gases are true?
Answer:The particles in liquids and gases can move past one another freely.
#CARRYONLEARNING #STUDYWELLWhich of the statements about liquids and gases are true?
Choosing:Both liquids and gases have a definite volume.
The particles in liquids and gases can move past one another freely
Both liquids and gases have a definite shape.
Neither liquids nor gases have a definite shape.
Answer:The particles in liquids and gases can move past one another freely.
#READINGHELPSWITHLEARNING #CARRYONLEARNING #STUDYWELL