Answer:
Approximately [tex]41.2\; {\rm ^{\circ} C}[/tex].
Explanation:
Let [tex]t\; {\rm ^{\circ} C}[/tex] be the final temperature of the water and the iron.
Temperature of the water would be increase by [tex](t - 38.00)\; {\rm ^{\circ} C}[/tex].
Temperature of the iron would be reduced by [tex](100.0 - t)\; {\rm ^{\circ} C}[/tex].
Let [tex]c[/tex] denote the specific heat of each material. Let [tex]m[/tex] denote the mass of the material. For a temperature change of [tex]\Delta t[/tex], the energy change involved would be:
[tex]Q = c\, m \, \Delta t[/tex].
The energy that the water need to absorb would be:
[tex]\begin{aligned}& Q(\text{water, absorbed}) \\ =\; & c(\text{water}) \, m(\text{water})\, \Delta t (\text{water}) \\ =\; & 4.181\; {\rm J \cdot g^{-1} \cdot K^{-1}} \times 50\; {\rm g} \times (t - 38.00)\; {\rm ^{\circ} C} \\ =\; & (209.05\, t - 7943.9)\; {\rm J} \end{aligned}[/tex].
The energy that the iron would need to release would be:
[tex]\begin{aligned}& Q(\text{iron, released}) \\ =\; & c(\text{iron}) \, m(\text{iron})\, \Delta t (\text{iron}) \\ =\; & 0.45\; {\rm J \cdot g^{-1} \cdot K^{-1}} \times 25.0\; {\rm g} \times (100.0 - t)\; {\rm ^{\circ} C} \\ =\; & (1125 - 11.25 \, t)\; {\rm J} \end{aligned}[/tex].
Since this calorimeter is insulated, the energy that the iron had released would be equal to the energy that the water had absorbed:
[tex]Q(\text{water, absorbed}) = Q(\text{iron, released})[/tex].
[tex]209.05\, t - 7943.9 = 1125 - 11.25\, t[/tex].
[tex]t \approx 41.2[/tex].
Thus, the final temperature of the water and the iron would be approximately [tex]41.2\; {\rm ^{\circ} C}[/tex].
5. Scientists always develop a plan when they try to learn something about our natural world. Which
sequence correctly shows the steps scientists follow in their plan?
A. make observations, develop an idea, obtain evidence, suggest an explanation
B. obtain evidence, suggest an explanation, develop an idea, make observations
C. suggest an explanation, obtain evidence, make observations, develop an idea
D. develop an idea, suggest an explanation, obtain evidence, make observations
A small container of perfume is opened in a classroom. Soon every student in the room smells the perfume. Explain this in terms of molecules.
When perfume or cologne is sprayed into the air, it turns into a gas and its particles mix with other air particles that quickly move around the room. This is because gas is the least dense of the three states of matter. It moves quickly into any space or volume because it has the least density. This is called diffusion, when molecules or particles move from areas with high concentration to low concentration areas.
Butane (C4 H10(g), Delta. Hf = â€"125. 6 kJ/mol) reacts with oxygen to produce carbon dioxide (CO2 , Delta. Hf = â€"393. 5 kJ/mol ) and water (H2 O, Delta. Hf = â€"241. 82 kJ/mol) according to the equation below. 2 upper C subscript 4 upper H subscript 10 (g) plus 13 upper o subscript 2 (g) right arrow 8 upper C upper O subscript 2 (g 0 plus 10 upper H subscript 2 upper O (g). What is the enthalpy of combustion (per mole) of C4H10 (g)? Use Delta H r x n equals the sum of delta H f of all the products minus the sum of delta H f of all the reactants. â€"2,657. 5 kJ/mol â€"5315. 0 kJ/mol â€"509. 7 kJ/mol â€"254. 8 kJ/mol.
The enthalpy of this reaction is -5315 KJ/mol.
The equation of the reaction is;
2C4H10(g) + 13O2(g) -----> 8CO2 (g) + 10H2O(g)
We know that the enthalpy of reaction can be obtained from the enthalpy of formation of the reactants and products as follows;
ΔHrxn = ΔHf(products) - ΔHf(reactants)
We have the following information from the question;
ΔHf C4H10 = - 125. 6 kJ/mol
ΔHf CO2 = - 393. 5 kJ/mol
ΔHf H2O = - 241. 82 kJ/mol
ΔHf O2 = 0 KJ/mol
Hence;
[(8 × (- 393. 5 )) + (10 × (- 241. 82))] - [2( - 125. 6))]
= -5315 KJ/mol
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Answer:
In the picture A kettle is boiling water and evaporating it we can see the water vapours coming out of the kettle and there is a paper on top of the kettle from where the water vapours are coming out .
Explanation:
is this right ?? i hope it helps
It takes 60 mL of 0.20 M of sodium hydroxide (NaOH) to neutralize 25 mL of carbonic acid (H2CO3) for the following chemical reaction:
2 NaOH + H2CO3 → Na2CO3 + 2 H2O
The concentration of the carbonic acid is _____.
It requires 60 mL of 0.20 M sodium hydroxide [tex](NaOH)[/tex] to neutralize 25 mL of carbonic acid [tex](H_2CO_3)[/tex], hence the carbonate ions concentration is [tex]0.24M[/tex].
Given:
Reaction:
[tex]\to \bold{2NaOH + H_2CO_3 \to Na_2CO_3 + 2H_20 }[/tex]
[tex]NaOH[/tex] volume [tex](V_B) = 60 \ ml[/tex]
[tex]H_2CO_3[/tex] Volume [tex](V_A) = 25\ ml[/tex]
[tex]NaOH[/tex] Molarity [tex](C_B) = 0.20\ M[/tex]
[tex]H_2CO_3[/tex] moles [tex](n_A) = 1[/tex]
[tex]NaOH[/tex] moles [tex](n_B) = 2[/tex]
To find:
[tex]H_2CO_3[/tex] Molarity [tex](C_A) =?[/tex]
Solution:
Using the neutralization reaction:
[tex]\to \frac{C_AV_A}{C_BV_B} =\frac{n_A}{n_B} \\\\[/tex]
[tex]\to C_B = 0.2\ M \\\\ \to n_A = 1 \\\\ \to n_B = 2 \\\\ \to V_B = 60\ ml \\\\ \to V_A = 25\ ml[/tex]
Calculating the [tex]C_A[/tex]:
[tex]\to \frac{C_A \times 25}{0.2 \times 60} =\frac{1}{2} \\\\\to C_A =\frac{1 \times 0.2 \times 60}{2 \times 25} \\\\\to C_A =\frac{1 \times 2 \times 12}{2 \times 5 \times 10} \\\\ \to C_A =\frac{ 12}{ 5 \times 10} \\\\\to C_A = \frac{6}{5 \times 5} \\\\\to C_A = \frac{6}{25} \\\\\to C_A=0.24\ M[/tex]
Therefore, the concentration of carbonic acid is "0.24M".
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The concentration of carbonic acid( H₂CO₃) is 0.24 M.
The given reaction:
2 NaOH + H₂CO₃ → Na₂CO₃ + 2H₂O
Volume of NaOH = 60mL
Volume of H₂CO₃ = 25 mL
Molarity of NaOH= 0.20M
To find:
Molarity of H₂CO₃=?
2 moles of NaOH and 1 mol of H₂CO₃ reacts to give 1 mol of Na₂CO₃.
Using the neutralization reaction:
Consider A to be NaOH and B to be H₂CO₃
[tex]\frac{\text{Number of moles of A}}{\text{Number of moles of B}} =\frac{\text{Molarity of A*Volume of A}}{\text{Molarity of B*Volume of B}}[/tex]
On substituting the values in order to calculate molarity of H₂CO₃:
[tex]\text{Molarity of B}=\frac{1*0.2*60}{2*25} \\\\\text{Molarity of B}=0.24M[/tex]
Therefore, the concentration of H₂CO₃ is 0.24 M.
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Which property determines whether a substance is a solid or liquid at room temperature?
Answer:
1. The kinetic energies of the particles (atoms, molecules, or ions) that make up a substance. Kinetic energy tends to keep the particles moving apart.
2. The attractive intermolecular forces between particles that tend to draw the particles together.
which bond shown are triple bonds
Answer:
Hey mate.....
Explanation:
This is ur answer.....
A triple bond is made of two pi bonds and one sigma bond. Examples of compounds with triple bonds include nitrogen gas, the cyanide ion, acetylene and carbon monoxide.
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Is boiling an egg a physical or a chemical change? Explain your answer.
Answer:
it's a chemistry change
Explanation:
this is because heat is causing permanent changes and can no longer be changed back to its original atate
What type of reaction takes place when using this enzyme (endergonic or exergonic)?
lactase is the enzyme
Answer:
we do the best possible in our
Consider the following reaction:
Mg + 2H2O Mg(OH)2 + H2 ΔH = -353 kJ
This reaction is
A.
exothermic because heat is released.
B.
endothermic because heat is released.
C.
endothermic because heat is absorbed.
D.
exothermic because heat is absorbed.
Answer:
A
Explanation:
I think it's the answer
How many sig figs are in 6.0395? Please no links-
Answer:
5 significant figures
Explanation:
The zeros as considered when they are in between or after numbers greater than zero.
Ex1: 0.005 = 1 significant figure
Ex2: 0.0050 = 2 significant figure
Ex3: 0.05500= 4 significant figure
Ex4: 5.00 = 1 significant figure
which reaction is an oxidation-reduction reaction?
Answer:
pl
saponification palmitate
why does hydrogen fluoride have a high boiling point
The intermolecular bonding for HF is van der Waals, whereas for HCL, the intermolecular bonding is hydrogen. Since the van der Waals bond is stronger than hydrogen, HF will have a higher boiling temperature. Since the covalent bond is stronger than van der Waals, HF will have a higher boiling temperature.
How is a stable hydrogen atom different from every other atom?
Answer:
a hydrogen atom contains only one proton in it's nucleus, while atoms of all other elements contain more than one proton
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Iridium crystallizes in a face-centered cubic unit cell that has an edge length of 3.833 Å.
(a) Calculate the atomic radius of an iridium atom.
(b) Calculate the density of iridium metal
a.
The atomic radius of iridium is 1.355 Å
For a face-centered cubic unit cell, with edge length, a and atomic radius r,
we have a² + a² = (4r)²
2a² = 16r²
r² = a²/8
r = a/√8
Since a = 3.833 Å,
Substituting this into the equation, we have
r = a/√8
r = 3.833 Å/√8
r = 3.833 Å/2.828
r = 1.355 Å
So, the atomic radius of iridium is 1.355 Å
b.
The density of iridium metal is 22.67 g/cm³
To find the density of the iridium metal, we need to find the mass of atoms per unit cell.
So, for the face centered cubic iridium atom, there are 6 faces per unit cell × 1/2 atoms per face + 4 corners per unit cell × 1/4 atoms per corner = 3 atoms + 1 atom = 4 atoms per unit cell.
So, the mass of the atoms in the unit cell is m = number of atoms/cell × number of moles/atom × molar mass of Iridium
= 4 atoms/cell × 1 mol/6.022 × 10²³ atoms × 192.22 g/mol
= 768.88/6.022 × 10²³ g/cell
= 127.68 × 10⁻²³ g/cell
= 1.2768 × 10⁻²¹ g/cell
Next, we need to find the volume of the unit cell which is V = a³
= (3.833 Å)³
= (3.833 × 10⁻¹⁰ m)³
= 56.314 × 10⁻³⁰ m
= 5.6314 × 10⁻²⁹ m
So, the density of iridium = mass of unit cell/volume of unit cell
= m/V
= 1.2768 × 10⁻²¹ g/cell ÷ 5.6314 × 10⁻²⁹ m
= 0.2267 × 10⁸ g/m³
= 0.2267 × 10⁸ g/m³ × 10⁻⁶ m³/cm³
= 0.2267 × 10² g/cm³
= 22.67 g/cm³
So, the density of iridium metal is 22.67 g/cm³
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Is bleach liquid starch?
Yes or No
Answer:
O it's not
Explanation:
Have a great day!
List THREE reasons why acidic soil can be a general problem to a natural ecosystem.
Answer:
Ok the poprtion would look like this : x 23
----------- = ----------
230 100
Explanation:
So for the last fill in it could be 52.9 or 60
i hope i got it correct lol pretty sure i did
What is released when a bond between two atoms breaks?
A. Electrical energy
B. Chemical energy
C. Intermolecular force
D. Intramolecular force
Please I need helppppp
Answer:
[tex]FeCl_{2} +H_{2} S->FeS + 2HCl[/tex]
Explanation:
I am assuming that we have to balance this equation. On the left side, we have one Fe, 2 H, 2 Cl, and 1 S. On the right side, we have 1 Fe, 1 H, 1 Cl, and 1 S. Adding a 2 as a coefficient in front of the HCl on the right side will make 2 H and 2 Cl instead, balancing the overall equation.
FeCl_{2} +H_{2} S- > FeS + 2HClFeCl 2 +H 2 S−>FeS+2HCl
Boron and antimony are good elements to use as
Answer: Semiconductors
Explanation:
It takes 25 mL of 0.20 M of hydrochloric acid (HCI) to neutralize 50 mL of
sodium hydroxide (NaOH). What is the concentration of sodium
hydroxide?
Answer:
0.1 M
Explanation:
(25 mL) (0.20 M) / 50 mL = 0.1 M
What is the chemical reaction by which organisms break down food
molecules for energy?
Answer:
cellular respiration
Explanation:
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F
norm
app
F
grav
F
fric
Which statement is true in this situation?
A. The size of Ffric is the same as the size of Fgrav-
B. The size of Fnorm is the same as the size of Ffric
C. The size of Ffric is the same as the size of Fapp:
D. The size of F
app is the same as the size of Fgrav
The statement is true in this situation is C. The size of Ffric is the same as the size of Fapp:
From the diagram, since the body is in equilibrium, the sum of vertical forces equals zero. Also, the sum of horizontal forces equal zero.
So, ∑Fx = 0 and ∑Fy = 0
Since Fapp acts in the negative x - direction and Ffric acts in the positive x - direction,
∑Fx = -Fapp + Ffric = 0
-Fapp + Ffric = 0
Fapp = Ffric
Also, since Fgrav acts in the negative y - direction and Fnorm acts in the positive y - direction,
∑Fy = Fnorm + (-Fgrav) = 0
Fnorm - Fgrav = 0
Fnorm = Fgrav
So, we see that the size of Fapp equals size of Ffric and the size of Fnorm equals the size of Fgrav.
So, the correct option is C
The statement which is true in this situation is C. The size of Ffric is the same as the size of Fapp.
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Match each type of reaction to its amount of potential energy. (PLEASE HELP )
what is the nature of the p-o bond in phosphorus pentoxide (p2o5)?
Answer:
the nature of the bond is covalent.
covalent bonds are bonds between 2 NON-METAL elements. since phosphorus and oxygen are both non-metals, the bond formed between them is covalent.
hope this answers your question!
How long is a bench? Select the best estimate.
4 centimeters
4 milllimeters
4 kilometers
4 meters
Answer:
4 meters
Explanation:
4 centimeters and millimeters are too small, while 4 kilometers is too large.
PLEASE HELP ME I NEED HELP ASAP SO BADLY
Answer:
160.3 g S
Explanation:
what is the speed of a skater who travels a distance of 210 m in a time of 10 seconds
Answer:
Speed =d/t. 200÷10=21÷1000=0.021 km/h
Explanation:
S=D/T
(07.05 HC A scientist investigating electrically-charged objects has decided to test if the number of times you rub a cloth against a balloon increases the amount of time it will stick to the wall. She wrote down her variables in a table. Variable Description Test The numbers of times she rubbed the cloth against the balloon Outcome The length of times the balloon sticks to the wall Control The cloth used in the experiment What would be her hypothesis for this experiment? (2 points) If you stick the balloon to a wall, then it will become electrically charged and stay there for a long period of time If you change the cloth used to change a balloon
Answer: the answer is b
Explanation:I took the test and got it
pls mark as brainliest if correct for you
How many molecules are present in this formula? 3H2 (SO)4
Molecules are formed when two or more atoms chemically bond together. In 3H₂(SO)₄, three molecules are present.
What are molecules?Molecules are the smallest unit present in any compound and are formed by a group of atoms. A number denoted in front of the chemical species is the coefficient that represents the number of molecules.
The coefficient present in front of the reactant or the product in a chemical reaction gives the number of the molecules present in a compound. As three is denoted in front of the sulphuric acid, hence will be the number of the molecules.
Therefore, there are three molecules present in sulphuric acid.
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