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Fill in the blank
you can find the run by subtracting the ________ -coordinate of the left point from that of the right point
you can find the run by subtracting the X coordinate of the left point from that of the right point
You can find by subtracting the variable
Calculate Delta H in KJ for the following reactions using heats of formation:
a) 2C2H6 (g) + 7O2 (g) ---> 4CO2 (g) +6H2O (g)
b) 2PbO (s) + PbO2 (s) ---> Pb3O4 (s)
Answer:
(a)[tex]\Delta H\textdegree = -2856.8\;\text{kJ}[/tex] per mole reaction.
(b)[tex]\Delta H\textdegree = -22.3\;\text{kJ}[/tex] per mole reaction.
Explanation:
What is the standard enthalpy of formation [tex]\Delta H_f\textdegree{}[/tex] of a substance? [tex]\Delta H_f\textdegree{}[/tex] the enthalpy change when one mole of the substance is formed from the most stable allotrope of its elements under standard conditions.
Naturally, [tex]\Delta H_f\textdegree{} = 0[/tex] for the most stable allotrope of each element under standard conditions. For example, oxygen [tex]\text{O}_2[/tex] (not ozone [tex]\text{O}_3[/tex]) is the most stable allotrope of oxygen. Also, under STP [tex]\text{O}_2[/tex] is a gas. Forming [tex]\text{O}_2\;(g)[/tex] from itself does not involve any chemical or physical change. As a result, [tex]\Delta H_f\textdegree{} = 0[/tex] for [tex]\text{O}_2\;(g)[/tex].
Look up standard enthalpy of formation [tex]\Delta H_f\textdegree{}[/tex] data for the rest of the species. In case one or more values are not available from your school, here are the published ones. Note the state symbols of the compounds (water/steam [tex]\text{H}_2\text{O}[/tex] in particular) and the sign of the enthalpy changes.
[tex]\text{C}_2\text{H}_6\;(g)[/tex]: [tex]-84.0\;\text{kJ}\cdot\text{mol}^{-1}[/tex];[tex]\text{CO}_2\;(g)[/tex]: [tex]-393.5\;\text{kJ}\cdot\text{mol}^{-1}[/tex];[tex]\text{H}_2\text{O}\;{\bf (g)}[/tex]: [tex]-241.8\;\text{kJ}\cdot\text{mol}^{-1}[/tex];[tex]\text{PbO}\;(s)[/tex]: [tex]-217.9\;\text{kJ}\cdot\text{mol}^{-1}[/tex];[tex]\text{PbO}_2\;(s)[/tex]: [tex]-276.6\;\text{kJ}\cdot\text{mol}^{-1}[/tex];[tex]\text{Pb}_3\text{O}_4\;(s)[/tex]: [tex]-734.7\;\text{kJ}\cdot\text{mol}^{-1}[/tex]How to calculate the enthalpy change of a reaction [tex]\Delta H_\text{rxn}[/tex] (or simply [tex]\Delta H[/tex] from enthalpies of formation?
Multiply the enthalpy of formation of each product by its coefficient in the equation.Find the sum of these values. Label the sum [tex]\Sigma (n\cdot \Delta_f(\text{Reactants}))[/tex] to show that this value takes the coefficients into account.Multiply the enthalpy of formation of each reactant by its coefficient in the equation.Find the sum of these values. Label the sum [tex]\Sigma (n\cdot \Delta_f(\text{Products}))[/tex] to show that this value takes the coefficient into account.Change = Final - Initial. So is the case with enthalpy changes. [tex]\Delta H_\text{rxn} = \Sigma (n\cdot \Delta_f(\textbf{Products})) - \Sigma (n\cdot \Delta_f(\textbf{Reactants}))[/tex].For the first reaction:
[tex]\Sigma (n\cdot \Delta_f(\text{Reactants})) = 4\times (-393.5) + 6\times (-241.8) = -3024.8\;\text{kJ}\cdot\text{mol}^{-1}[/tex];[tex]\Sigma (n\cdot \Delta_f(\text{Products})) = 2\times (-84.0) + 7\times 0 = -168.0\;\text{kJ}\cdot\text{mol}^{-1}[/tex];[tex]\begin{aligned}\Delta H_\text{rxn} &= \Sigma (n\cdot \Delta_f(\textbf{Products})) - \Sigma (n\cdot \Delta_f(\textbf{Reactants}))\\ &= (-3024.8\;\text{kJ}\cdot\text{mol}^{-1}) - (-168.0\;\text{kJ}\cdot\text{mol}^{-1})\\ &= -2856.8\;\text{kJ}\cdot\text{mol}^{-1} \end{aligned}[/tex].Try these steps for the second reaction:
[tex]\Delta H_\text{rxn} = -22.3\;\text{kJ}\cdot\text{mol}^{-1}[/tex].
Which type of solid has the lowest and highest melting point?
lowest melting point-covalent solids
highest melting point-ionic solids
Molecular solids like ice tend to have lower melting points due to weaker intermolecular forces, while ionic solids such as sodium chloride have high melting points due to strong ionic bonds. Network covalent solids also have high melting points, whereas amorphous solids soften over a range of temperatures.
Explanation:The melting point of a solid is the temperature at which the solid changes into a liquid. It reflects how much kinetic energy is required for the particles within a solid to overcome the attractive forces keeping them in place. In general, molecular solids, such as ice (melting point of 0°C), tend to have lower melting points due to weaker intermolecular forces like hydrogen bonds or London dispersion forces. On the other hand, ionic solids, such as sodium chloride (melting point of 801°C), display the highest melting points because the ionic bonds between their ions are very strong.
Network covalent solids often have high melting points as well since the atoms within the network are bonded by covalent bonds that require significant energy to break. By contrast, amorphous solids like butter do not have a sharp melting point but rather soften over a range of temperatures due to the lack of a well-ordered molecular structure like that seen in crystalline solids.
The table shows the concentration of a reactant in the reaction mixture over a period of time.
Reactant Concentration
Time Concentration
0 s 1.8 M
210 s 1.2 M
450 s 0.8 M
580 s 0.6 M
720 s 0.4 M
What is the average rate of the reaction over the first 580 seconds?
A. 1.6 × 10−3
B. 1.9 × 10−3
C. 2.0 × 10−3
D. 2.2 × 10−3
The average rate of the reaction over the first 580 seconds is approximately [tex]2.07 \times 10^{(-3)} M/s[/tex]. Thus, option C is correct.
To find the average rate of the reaction over the first 580 seconds, we can use the formula:
[tex]\[ \text{Average rate} = \frac{\text{Change in concentration}}{\text{Change in time}} \][/tex]
Given the concentrations at 0 s and 580 s, and the corresponding times, we can calculate the change in concentration and change in time:
Change in concentration = 1.8 M - 0.6 M = 1.2 M
Change in time = 580 s - 0 s = 580 s
Now, we can calculate the average rate:
Average rate = [tex]\(\frac{1.2 \text{ M}}{580 \text{ s}}\)[/tex]
Average rate = [tex]\(2.07 \times 10^{-3}\) M/s[/tex]
Therefore, the average rate of the reaction over the first 580 seconds is approximately [tex]2.07 \times 10^{(-3)} M/s[/tex]. Since this is closest to option C [tex](2.0 \times 10^{(-3)})[/tex], the answer is C.
If a gas at 25.0 degrees Celsius occupies 7.20 liters at a pressure of 1.00 atm, what will be its volume at a pressure of 2.50 atm?
Answer:
2.88 L.
Explanation:
To calculate the no. of moles of a gas, we can use the general law of ideal gas: PV = nRT.where, P is the pressure of the gas in atm.
V is the volume of the gas in L.
n is the no. of moles of the gas in mol.
R is the general gas constant.
T is the temperature of the gas in K.
If n and T is constant, and have two different values of (P and V):P₁V₁ = P₂V₂
P₁ = 1.0 atm, V₁ = 7.2 L.
P₂ = 2.5 atm, V₂ = ??? L.
∴ V₂ = P₁V₁/P₂ = (1.0 atm)(7.2 L)/(2.5 atm) = 2.88 L.
a solution has a pH of 5.4. write the formula you will use to calculate the (H+)
Answer:
3.981 x 10⁻⁶.
Explanation:
∵ pH = - log[H⁺]
∴ 5.4 = - log[H⁺]
∴ log[H⁺] = - 5.4
∴ [H⁺] = 3.981 x 10⁻⁶.
Answer:
pH = - log[H⁺]
=> 3.981 x 10⁻⁶
Explanation:
What causes an electric current in a wire?
A) Electrons move because of heat
B) Electrons build up in the wire and create a charge
C) Electric fields cause atoms to move in the wire
D) Electrons flow because of electrical attraction and repulsion
Thank you :3
flow of charge of electrons cause current in wire.
Electric current in a wire causes an electrons flow because of electrical attraction and repulsion. Option D is correct.
Electric current is the flow of electrons through a conductor. Conductors are materials that allow electrons to flow freely. Wires are made of conductors, such as copper or aluminum. When a voltage difference is applied to a wire, it creates an electric field. The electric field causes the electrons in the wire to move.
The electrons move from the negative side of the voltage source to the positive side. The movement of electrons through a wire is what creates an electric current. The amount of current that flows through a wire depends on the strength of the electric field and the resistance of the wire. Electrons are negatively charged particles that orbit the nucleus of an atom. Option D is correct.
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Water’s molar mass is 18.01 g/mol. The molar mass of glycerol is 92.09 g/mol. At 25°C, glycerol is more viscous than water. Which substance has the stronger intermolecular attraction?
Answer:
glycerol because it is more viscous and has a larger molar mass than water.
Explanation:
Viscosity depends on inter-molecular interactions.
The predominant inter-molecular force in water and glycerol is hydrogen bonding.
Hydrogen bond is an electrostatic attraction between two polar groups in which one group has hydrogen atom (H) and another group has highly electronegative atom such as nitrogen (like in this molecule), oxygen (O) or fluorine (F).
Final answer:
Water has stronger intermolecular attraction compared to glycerol because water has extensive hydrogen bonding. Hydrogen bonding is a strong intermolecular force that occurs when a hydrogen atom is bonded to a highly electronegative atom like oxygen or nitrogen. Glycerol, on the other hand, does not have hydrogen bonding.
Explanation:
The intermolecular attractions or forces between molecules determine the strength of the attractive forces in a substance. In this case, water has stronger intermolecular attraction compared to glycerol because water has extensive hydrogen bonding. Hydrogen bonding is a strong intermolecular force that occurs when a hydrogen atom is bonded to a highly electronegative atom like oxygen or nitrogen. Glycerol, on the other hand, does not have hydrogen bonding.
Water's molar mass is 18.01 g/mol and it can form hydrogen bonds, which makes it highly cohesive and viscous. Glycerol's molar mass is 92.09 g/mol and it does not have the ability to form hydrogen bonds. Therefore, water has stronger intermolecular attractions due to hydrogen bonding, resulting in its higher viscosity compared to glycerol.
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In your own words, describe the connection between the heat from earth’s core and the movement of tectonic plates.
The immensely strong heat creates conviction cells to create movement as it follows the currents.
Final answer:
Heat from Earth's core causes convection currents in the mantle, driving the movement of tectonic plates. This movement can create divergent and convergent plate boundaries, leading to the formation of new lithosphere, mountain ranges, earthquakes, and volcanic activity.
Explanation:
The core of the Earth is extremely hot, and this heat plays a crucial role in the movement of tectonic plates that make up the planet's crust and upper mantle. The process of heat transfer from the core to the mantle is known as convection. In this process, warmer material rises due to being less dense, and cooler material sinks because it is denser. This continuous cycle of rising and sinking material creates convection currents in the mantle.
These convection currents are the primary driving force behind the movement of tectonic plates. At divergent boundaries, where two plates are moving apart, new lithosphere forms at ocean ridges due to upwelling currents. Conversely, at convergent boundaries, where plates move toward each other, one plate can be forced under another in a process called subduction, which can lead to the formation of mountains, earthquakes, and volcanic activity. Therefore, the heat from Earth's core is essential in driving the dynamic processes that shape the planet's surface.
iron reacts with sulfur to form iron sulfide. If 60 grams of iron reacts with sulfur to produce 90 grams of iron sulfide how much sulfur has been used in the chemical reaction
Answer:
34.44 g.
Explanation:
The balanced equation for the reaction is:Fe + S → FeS,
It is clear that 1.0 mol of Fe reacts with 1.0 mol of S to produce 1.0 mol FeS.
We need to calculate the no. of moles of 60 grams of iron and 90 grams of iron sulfide:
no. of moles of Fe = mass/atomic mass = (60.0 g)/(55.845 g/mol) = 1.074 mol.
no. of moles of FeS = mass/molar mass = (90.0 g)/(87.91 g/mol) = 1.024 mol.
∵ Fe reacts with S with (1: 1) molar ratio.
∴ The no. of moles of S needed to react with Fe is 1.074 mol.
∴ The no. of grams of S needed = no. of moles x molar mass = (1.074 mol)(32.065 g/mol) = 34.44 g.
Answer:
The answer is:
A. 30 grams
Explanation:
1. scientists can use rock layers to determine which of the following?
A. The mass of Earth
B. The size of Earth
C. The age of Earth
D. The amount of land on Earth
2. Fossils in ________ layers of rock are generally estimated to be ______ than fossils found in the deeper layers.
A. older, younger
B. newer, younger
C. older, older
D. newer, older
3. New evidence can lead to a change in scientific knowledge
true or false
Answer:1. Age of earth 2. D. Newer, Older 3. True
Explanation:
Scientists use rock layers to determine the age of Earth. Fossils in newer, or higher, rock layers are typically younger than those in older or deeper layers. And yes, new evidence can indeed lead to changes in scientific understanding.
Explanation:1. Scientists use rock layers primarily to determine the age of Earth. They do this through a method called stratigraphy, wherein they study the arrangement of rock layers and relative ages to understand the Earth's past. So, the correct answer is C. The age of Earth.
2. Generally, fossils found in newer layers of rock are estimated to be younger than those found in deeper (or older) layers. As sediment is deposited over time, newer layers form on top of older ones, and as a result, newer fossils are typically found closer to the surface. So the correct answer is B. newer, younger.
3. True. New evidence can definitely lead to a change in scientific knowledge. Science is a dynamic and evolving field and new discoveries or data can modify or even completely change previously held theories and understandings.
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35 POINTS!!!!!!!!!!!!!!
explain the concept of conservation of natural resources
Air, soil, plants, fuels and water are examples of natural resources. Some of these (ex. air & water) are renewable. Some however are nonrenewable (ex. fuels). If not conserved and protected, we may lose some of these resources to pollution or depletion.
The Earth's natural resources include air, water, soil, minerals, fuels, plants, and animals. Conservation is the practice of caring for these resourcesso all living things can benefit from them now and in the future. ... These are renewable resources. Otherresources, such as fossil fuels, cannot be replaced at all.
Source: National Geography
Caffeine has the following percent composition: carbon 49.48%, hydrogen 5.19%, oxygen 16.48% and nitrogen 28.85%. Its molecular weight is 194.19 g/mol. What is its molecular formula?
Here is the solution hope u understand
The empirical formula mass of the compound is calculated to be 97 g. Thus, molecular formula of compound is C₈H₁₀O₂N₄.
What is empirical formula?Empirical formula of a compound is derived from the mole ratio of each element in the compound. The molecular formula of the compound can be obtained by multiplying the empirical formula with the integer calculated by dividing the molecular mass by formula mass.
Given 49.48 % of C means 49.48 g in 100 g = 49.48/12= 4.12 moles
mass of oxygen = 16 g/mol
moles in 16.48 g = 16.48.=/ 16 = 1.03 moles.
mass of H = 1 g/mol, moles in 5.19 = 5.19 moles.
mass of nitrogen = 14 g/mol, moles in 28.85 g = 28.85/14 = 2.06 moles.
Divide each numbers with the least number among them that is by 1.03, we get the ratios 4: 5: 1: 2. for C, H, O and N respectively.
The empirical formula mass = (4 × 12) + 5 + 16 +( 14×2 ) = 97 g
divide the molecular mass by 97: 194.19 /97 = 2.
Now, multiply the empirical molar ratio by 2 we get 8: 10 : 2:4.
Therefore, the molecular formula of the compound is C₈H₁₀O₂N₄.
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Mitochondria _
Plant
Answer:
??????
Explanation:
I believe this question is asking what a mitochondria does for a plant cell?
The mitochondria is the digestive system in a plant cell. It’s job is to take in nutrients, break it down, and then create energy from it. The mitochondria is a crucial part of cellular respiration.
Use this diagram to determine which of the following statements is true.
Answer:
D. Catalysts speed up the rate of reactions by lowering the amount of energy required for the reaction to proceed.
Explanation:
A catalyst is a substance that:
speeds up the rate of a reaction .does not alter the products of the reaction .is unchanged chemically and in mass at the end of the reaction.A catalyst provides an alternative reaction pathway that has a lower activation energy than the uncatalyzed reaction.
The figure shows how the energy of the reactants and products change during a reaction.
The point at which a stream empties into another body of water is the _____ of the stream
The mouth (can also be a delta or estuary) is where a stream empties into another body of water.
Answer:
The given blank can be filled with mouth.
Explanation:
A body of water comprising surface water flowing within the banks and bed of a channel is known as a stream. The stream comprises groundwater and surface fluxes, which reacts towards the geomorphological, geological, biotic, and hydrological controls. The lengthy and large streams are generally termed as rivers. The mouth of the stream is considered as the point at which the stream releases probably through a delta or an estuary, into a standing water body like ocean or lake.
Which of the following is an example of cell division at work?
A.
A muscle contracts.
B.
A dog digests food.
C.
A tree grows taller.
D.
A plant dies.
Answer:
C-a tree grows taller
Explanation:
Cell division is cellular reproduction, so C is the only option involving growth/reproducing.
Answer:
The correct answer to this question is: C "A Tree Grows Taller"
Explanation:
Cell division is cellular reproduction. All mammals eat to take in energy. Plants take in energy from the sun to use and collect the same energy which is then used to do various things. The tree is using Mitosis to its advantage so it can grow. That is why C is the correct answer.
Hope this helped have an amazing day!
A gas occupies 49 liters at a pressure of 367 mm Hg. What is the volume when the pressure is increased to 784 mm Hg?
Answer:
22.94 L.
Explanation:
We can use the general law of ideal gas: PV = nRT.
where, P is the pressure of the gas in atm.
V is the volume of the gas in L.
n is the no. of moles of the gas in mol.
R is the general gas constant,
T is the temperature of the gas in K.
If n and T are constant, and have two different values of V and P:
P₁V₁ = P₂V₂
P₁ = 367.0 mm Hg, V₁ = 49.0 L.
P₂ = 784.0 mm Hg, V₂ = ??? L.
∴ V₂ = P₁V₁/P₂ = (367.0 mm Hg)(49.0 L)/(784.0 mm Hg) = 22.94 L.
A half life of cobalt is 5.27years. Approximately how much a 399 g sample will remain after 20 years?
Answer:
= 28.745 g
Explanation:
Half life is the time taken by a radioactive element to decay by half the original amount.
Therefore;
New mass = Original mass × (1/2)^n
Where n is the number of half lives, in this case, n = 20/5.27 = 3.795
Therefore;
New mass = 399 g × (1/2)^3.795
= 28.745 g
What are the concentrations of hydroxide and hydronium ions in a solution with a pH of 4.6?
Answer: 2.5 × 10⁻⁵ M H₃O⁺ and 4.0 × 10⁻¹⁰ M OH⁻
Explanation:
∵ pH = - log[H₃O⁺]
∴ 4.6 = - log[H₃O⁺].
∴ log[H₃O⁺] = - 4.6.
∴ [H₃O⁺] = 2.51 x 10⁻⁵.
∵ [H₃O⁺][OH⁻] = 10⁻¹⁴.
[H₃O⁺] = 2.51 x 10⁻⁵ M.
∴ [OH⁻] = 10⁻¹⁴/[H₃O⁺] = 10⁻¹⁴/(2.51 x 10⁻⁵ M) = 3.98 × 10⁻¹⁰ M ≅ 4.0 × 10⁻¹⁰ M.
Answer : The concentration of hydroxide and hydronium ion is, [tex]3.9\times 10^{-10}M[/tex] and [tex]2.5\times 10^{-5}M[/tex]
Explanation: Given,
pH = 4.6
pH : It is defined as the negative logarithm of hydrogen ion and hydronium ion concentration.
[tex]pH=-\log [H_3O^+][/tex]
First we have to calculate the [tex]H^+[/tex] concentration.
[tex]pH=-\log [H_3O^+][/tex]
[tex]4.6=-\log [H_3O^+][/tex]
[tex][H_3O^+]=2.5\times 10^{-5}M[/tex]
Now we have to calculate the pOH.
[tex]pH+pOH=14\\\\pOH=14-pH\\\\pOH=14-4.6=9.4[/tex]
Now we have to calculate the [tex]OH^-[/tex] concentration.
[tex]pOH=-\log [OH^-][/tex]
[tex]9.4=-\log [OH^-][/tex]
[tex][OH^-]=3.9\times 10^{-10}M[/tex]
Therefore, the concentration of hydroxide and hydronium ion is, [tex]3.9\times 10^{-10}M[/tex] and [tex]2.5\times 10^{-5}M[/tex]
A sample of glucose ( C6H12O6 ) of mass 8.44 grams is dissolved in 2.11 kg water. What is the freezing point of this solution? The freezing point depression constant, Kf , for water is 1.86 °C/mol. (Round your answer to the nearest thousandth)
Answer:
- 0.0413°C ≅ - 0.041°C (nearest thousands).
Explanation:
Adding solute to water causes the depression of the freezing point.We have the relation:ΔTf = Kf.m,
Where,
ΔTf is the change in the freezing point.
Kf is the freezing point depression constant (Kf = 1.86 °C/m).
m is the molality of the solution.
Molality is the no. of moles of solute per kg of the solution.
no. of moles of solute (glucose) = mass/molar mass = (8.44 g)/(180.156 g/mol) = 0.04685 mol.∴ molality (m) = no. of moles of solute/kg of solvent = (0.04685 mol)/(2.11 kg) = 0.0222 m.
∴ ΔTf = Kf.m = (1.86 °C/m)(0.0222 m) = 0.0413°C.
∴ The freezing point of the solution = the freezing point of water - ΔTf = 0.0°C - 0.0413°C = - 0.0413°C ≅ - 0.041°C (nearest thousands).
Answer:
-0.041
Explanation:
The pH of a solution is 4.36. What is the pOH?
Answer:
9.64
Explanation:
pH + pOH = 14
Since pOH = 4.36, pH would be:
pH = 14 - pOH
pH = 14 - 4.36
pH = 9.64
The answer is 9.46
9.46 pOH
What is the mass of one mole of S8?
Answer:
256.52 g/m
Explanation:
Each S has a molecular mass of 32.056 g/mol so multiply that by 8 and you get 256.52.
A 2.5-liter sample of a gas at 2.0 atm and 300.0 K has 0.30 mole of the gas. If 0.15 mole of the gas is added to the sample at the same temperature and pressure, what is the final volume of the gas? 3.4 liters 3.8 liters 4.2 liters 4.7 liters
Answer:
3.8 liters
Explanation:
According to Avogadro’s Law of gases
at constant temperature and pressure, the volume of all gases constitutes an equal number of molecules. In other words, the volume of any gas is directly proportional to the number of molecules of that gas.
∴ V ∝ n or (V₁/V₂) = (n₁/n₂)
V₁= 2.5 L
n₁= 0.3 mol
n₂= 0.3 mol + 0.15 mol = 0.45 mol
using cross multiplication
(2.5 L / V₂) = (0.3 mol / 0.45 mol)
V₂= 3.8 L
∴ The right choice is 3.8 liters
Answer:
3.8 liters
Explanation:
Sound waves with a large distance between A and B would be sound waves that have a large ________ and produce loud sounds.
A) amplitude
B) frequency
C) pitch
D) resonance
Answer:
Amplitude
Explanation:
Answer:
a. amplitude
Explanation:
A large C would indicate a large amplitude and a loud sound. When the amplitude increases in a compression wave, there is an increase in the density of the medium, and in the pressure exerted by the particles.
Which half-reaction correctly describes an oxidation?
Answer:
The last choice is oxidation.
Explanation:
The this is a reaction in which the oxidation number of chromium metal
( 0 ) goes the an oxidation number of 3 in Cr3+.
Answer : The correct option is, [tex]Cr(s)\rightarrow Cr^{3+}(aq)+3e^-[/tex]
Explanation :
Redox reaction : It is a reaction in which the oxidation and reduction reaction takes place simultaneously.
Oxidation reaction : It is a reaction in which a substance looses its electrons. In this, oxidation state of an element increases. Or we can say that in oxidation, the loss of electrons takes place.
Reduction reaction : It is a reaction in which a substance gains electrons. In this, oxidation state of an element decreases. Or we can say that in reduction, the gain of electrons takes place.
The correct oxidation-half reaction will be :
[tex]Cr(s)\rightarrow Cr^{3+}(aq)+3e^-[/tex]
In this half oxidation reaction, the oxidation state of 'Cr' changes from (0) to (+3) that means the oxidation state increases that means it shows oxidation.
A solution was prepared by mixing 50.0 g
MgSO4
and 1000.0 mL water at 25.0°C. The density of the water at this temperature is 0.997 g/mL. What is the percent mass of
MgSO4
in this solution? (Round your answer to the nearest hundredth.)
Answer:
4.78 %.
Explanation:
mass percent is the ratio of the mass of the solute to the mass of the solution multiplied by 100.
mass % = (mass of solute/mass of solution) x 100.
mass of MgSO₄ = 50.0 g,
mass of water = d.V = (0.997 g/mL)(1000.0 mL) = 997.0 g.
mass of the solution = mass of water + mass of MgSO₄ = 997.0 g + 50.0 g = 1047.0 g.
∴ mass % = (mass of solute/mass of solution) x 100 = (50.0 g/1047.0 g) x 100 = 4.776 % ≅ 4.78 %.
The percent mass of [tex]MgSO_4[/tex] in the solution is approximately [tex]4.77\%[/tex].
To find the percent mass of [tex]MgSO_4[/tex] in the solution, we need to calculate the total mass of the solution and then determine the mass of [tex]MgSO_4[/tex] in it.
Given:
[tex]Mass \ of \ MgSO_4 = 50.0 \ g[/tex]
[tex]Volume \ of \ water = 1000.0\ mL[/tex]
[tex]Density\ of\ water = 0.997 \ g/mL[/tex]
First, we'll find the mass of the water using its density:
[tex]\[ \text{Mass of water} = \text{Density} \times \text{Volume} \][/tex]
[tex]\[ \text{Mass of water} = 0.997 \, \text{g/mL} \times 1000.0 \, \text{mL} \][/tex]
[tex]\[ \text{Mass of water} = 997 \, \text{g} \][/tex]
Now, we'll calculate the total mass of the solution:
[tex]\[ \text{Total mass of solution} = \text{Mass of MgSO}_4 + \text{Mass of water} \][/tex]
[tex]\[ \text{Total mass of solution} = 50.0 \, \text{g} + 997 \, \text{g} \][/tex]
[tex]\[ \text{Total mass of solution} = 1047 \, \text{g} \][/tex]
Next, we'll determine the percent mass of [tex]MgSO_4[/tex] in the solution:
[tex]\[ \text{Percent mass of MgSO}_4 = \left( \frac{\text{Mass of MgSO}_4}{\text{Total mass of solution}} \right) \times 100\% \][/tex]
[tex]\[ \text{Percent mass of MgSO}_4 = \left( \frac{50.0 \, \text{g}}{1047 \, \text{g}} \right) \times 100\% \][/tex]
[tex]\[ \text{Percent mass of MgSO}_4 = 4.77\% \][/tex]
How many joules are required to change 1kg of ice at-10°C to water at 15°C?
Answer:
[tex]\boxed{\text{417 kJ}}[/tex]
Explanation:
There are three heat transfers in this process:
Total heat = warming the ice + melting the ice + warming the water
q = q₁ + q₂ + q₃
q = mC₁ΔT₁ + mΔHfus + mC₂ΔT₂
Let's calculate these heat transfers separately.
Data:
m = 1 kg = 1000 g
C₁ = 2.108 J·°C⁻¹g⁻¹
C₂ = 4.184 J·°C⁻¹g⁻¹
ΔHfus = 333 J/g
Tmax = 15 °C
m.p. = 0 °C
Tmin = -10 °C
Calculations:
ΔT₁ = 0 – (-10) = 10 °C
q₁ = 1000 × 2.108 × 10 = 21 080J = 21.08 kJ
q₂ = 1000 × 333 = 333 000 J =333 kJ
ΔT₂ = 15 - 0 = 15 °C
q₃ = 1000 × 4.184 × 15 = 62 760 J = 62.76 kJ
q = 21.08 + 333 + 62.76 = 417 kJ
You must add [tex]\boxed{\textbf{417 kJ}}[/tex].
What is the purpose of graphics in scientific articles
Answer:
Graphics can sometimes convey more information in a brief amount of space than an author can explain in a paragraph.
At 0°C, frozen water (ice) changes to liquid water. When an ice cube is placed on something that is warmer than it, heat will move from the warmer substance to the water until
A.
both objects are the same temperature.
B.
the ice melts.
C.
the ice reaches 0°C.
D.
the warmer substance cools to 0°C.
Answer:hi guys it is both objects are the same temperature
Explanation:
Heat transfers from a warmer object to a colder one (such as an ice cube) until both objects are at the same temperature. This is a process known as conduction.
Explanation:When an ice cube is placed on an object that is warmer than it, heat will be transferred from the warmer substance to the ice cube. This process will continue until both objects are the same temperature. This is explained by the physics law of heat transfer, specifically conduction, which is the process where heat energy is transferred between substances in direct contact with each other.
The warmer object will lose heat to the colder object (the ice cube) until equilibrium is reached and both objects have the same temperature. It may also coincide with other options like the ice melting or ice reaching 0°C, but this depends on the initial temperature of the warmer object.
Learn more about Heat Transfer here:https://brainly.com/question/13433948
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