When a 38 gram sample of water freezes it releases approximately 12.66 kJ of heat. This is because freezing is an exothermic process, meaning the substance releases energy in the form of heat.
Explanation:The process of freezing water is exothermic, meaning it releases heat. The amount of heat released when water freezes can be calculated using its enthalpy change upon freezing. For water, the enthalpy change upon freezing is approximately -6.0 kJ/mol. Here's how to calculate:
First, make sure that you have the appropriate conversion factors. Given that the molar mass of water is 18.015 g/mol, a 38 gram sample of water would be approximately 2.11 moles.Now use this information with the enthalpy change upon freezing (which is -6.0 kJ/mol) to calculate the amount of energy change (which will be measure in kJ). Multiply the number of moles by the enthalpy change: 2.11 moles * -6.0 kJ/mol = -12.66 kJ (negative because heat is being released). So, a 38 gram sample of water would release approximately 12.66 kJ of heat when it freezes.Learn more about Heat of freezing here:https://brainly.com/question/32765057
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When a 38 gram sample of water freezes it releases approximately 12.66 kJ of heat.
This is because freezing is an exothermic process, meaning the substance releases energy in the form of heat
To freeze a 38-gram sample of water, 12,692 joules of heat is released, calculated using the latent heat of fusion for water which is 334 J/g.To determine the amount of heat released when a 38-gram sample of water freezes, we must use the latent heat of fusion. The heat of fusion for water is 334 J/g. This value represents the amount of heat energy released or absorbed during the phase change of water from liquid to solid, and vice versa, without changing temperature.The formula to calculate the heat released is:
Heat released (Q) = mass (m) x heat of fusion (Lf)Given that: m = 38 grams and Lf = 334 J/g, we can plug in the values:
Q = 38 g x 334 J/g = 12,692 JTherefore, 12.66 kJ of heat is released when a 38-gram sample of water freezes.
Correct question is: How much heat is released by a 38-gram sample of water to freeze at its freezing point?
Describe how electron movement is related to the bonding in methane, ch4.
1. Which of the following does NOT indicate that a chemical change may have taken place?
A. fracture formation
B. gas production
C. precipitate formation
D. energy transfer
2. What happens to matter during a chemical reaction?
A. matter is neither destroyed or created.
B. some matter is destroyed
C. some matter is created
D. some matter is destroyed and some is created.
What is our more modern word for caloric?
How many grams of Cl are in 535 g of CaCl₂?
convert 1.75 × 1024 atoms of carbon to moles of carbon.
Answer: The number of moles of carbon is 2.90 mol.
Explanation:
We are given:
Number of atoms of carbon = [tex]1.75\times 10^{24}[/tex]
According to mole concept:
[tex]6.022\time 10^{23}[/tex] number of atoms are contained in 1 mole of an element.
So, [tex]1.75\times 10^{24}[/tex] number of atoms will be contained in = [tex]\frac{1}{6.022\times 10^{23}}\times 1.75\times 10^{24}=2.90mol[/tex] of carbon.
Hence, the number of moles of carbon is 2.90 mol.
Organs combine to form Blank Space __________.
A.organ systems
B.tissues
C.organisms
D.cells
Binary ionic compounds are named in what pattern?
A. The metal followed by nonmetal.
B. The nonmetal followed by the metal.
C. The metal followed by the polyatomic ion.
D. The anion followed by the cation.
the bonding of two amino acids to form a larger molecule requires the addition of nitrogen the release of carbon dioxide the release of a water molecule the addition of a water molecule
Which of the following compounds is a molecule?
NaCl
MgBr2
H2
AlCl3 Which of the following compounds is a molecule?
NaCl
MgBr2
H2
AlCl3
Answer:
H2
Explanation:
It is a diatomic molecule, meaning it is formed through covalent bonding.
Water is called the “universal solvent.” Which statement best explains this description with respect to ionic compounds?
Answer is: C. Water can dissociate many ionic compounds through ion-dipole interactions.
For example, dissociation of potassium bromide: KBr(aq) → K⁺(aq) + Br⁻(aq).
Some ionic compounds cannot dissociate in water, for example calcium sulfate (CaSO₄), silver chloride (AgCl), lead(II)-carbonate (PbCO₃).
An ion-dipole is electrostatic interaction between a charged ion (cations and anions) and a molecule that has a dipole (in this example water).
Dipole is a separation of positive and negative charges. In water, hydrogen has positive and oxygen has negative charge.
Iron (Fe) reacts with copper sulfate (CuSO4) to form iron (II) sulfate. In this reaction, Cu2+ gains electrons to form Cu. Which statement is true about this reaction?
Fe(s) + CuSO4(aq) → FeSO4(aq) + Cu(s)
A.) Cu undergoes decomposition.
B.) Cu undergoes oxidation.
C.) Cu undergoes reduction.
D.) Cu undergoes combustion.
C. Cu undergoes reduction.
Answer: C.) Cu undergoes reduction.
Explanation:
[tex]Fe(s)+CuSO_4(aq)\rightarrow FeSO_4(aq)+Cu(s)[/tex]
I) Oxidation reaction : involves loss of electrons and there is an increase in oxidation state number.
[tex]Fe\rightarrow Fe^{2+}+2e^-[/tex]
Fe metal has undergone oxidation, as its oxidation state is changing from 0 to +2 in [tex]FeSO_4[/tex].
ii) Reduction reaction : involves gain of electrons and there is a decrease in oxidation state number.
[tex]Cu^{2+}+2e^-\rightarrow Cu[/tex]
Copper(II) ion has undergone reduction, as its oxidation state is changing from 2+ to 0. Copper ions are getting converted into copper metal.
A difference in electric potential is commonly known as voltage, and is provided by standard batteries. when a battery "dies", this is because the __________ within the battery no longer exists.
Answer:
voltage difference
Explanation:
Remember, a Difference in voltage must exist in order to have current flow.
Which contains more molecules of water, 4.55 cm3 of ice (0.917 g/cm3 ) at 0◦C or 4.55 cm3 of liquid water at 0◦C? 1. the ice 2. the liquid?
How many more molecules?
Answer in units of molec.
I know its the liquad water but how do I find how many more molecules there are
I did:
m/v=d for ice and liquad water
ice mass= 0.917*5= 4.585
liquad water mass= .9998*5= 4.995
then subtracted 4.995-4.585= .41 and converted g to mol= .02277*6.022x10^23= 1.3716E22 but its wrong!!
Answer:
answer was A on edunity
Explanation:
What is 0.000000639 in scientific notation
Hello!
Order of magnitude of a measure is an estimate of the base power 10 closest to a given measure.
The scientific notation (N) of 0.000000639 (x), being (number of decimal places) y, knowing that the scientific notation according to the rule of scientific notation, before the comma can only have the numbers 1 to 9, let's see:
[tex] N = x*10^y [/tex]
[tex] N = 0.000000639*10^y [/tex]
[tex] \boxed{\boxed{N = 6.39*10^{-7}}}\end{array}}\qquad\checkmark [/tex]
note: Moved 7 decimal places to the right negatively
I Hope this helps, greetings ... DexteR! =)
Enter the molecular formula for butane, C4H10.
Express your answer as a chemical formula.
Which set of coefficients would balance the following chemical equation? H3PO4 + RbOH → H2O + Rb3PO4
Answer:
The balanced equation is:
[tex] H_3PO_4 + 3 RbOH \longrightarrow 3 H_2O +Rb_3PO_4[/tex]
Explanation:
Hi, step by step:
1) Balance the Rb:
[tex]H_3PO_4 + 3 RbOH \longrightarrow H_2O +Rb_3PO_4[/tex]
2) Balance the phosphate:
[tex]1 H_3PO_4 + 3 RbOH \longrightarrow H_2O +Rb_3PO_4[/tex]
3) Balance the water:
[tex]1 H_3PO_4 + 3 RbOH \longrightarrow 3 H_2O +Rb_3PO_4[/tex]
A reaction produces 0.883 moles of H₂O. How many molecules are produced?
How is a combustion reaction like the respiration reaction? List many similarities as you can.
How does the written lewis structure for potassium chloride differ from that of hydrogen chloride?
Final answer:
The Lewis structure of potassium chloride (KCl) shows K+ with no electrons around it and Cl- with eight dots, signifying ionic bonds and full valence shells. In contrast, hydrogen chloride (HCl) has a single line or pair of dots between H and Cl, representing a pair of shared electrons in a covalent bond, with Cl also having three pairs of lone electrons.
Explanation:
The Lewis structures for potassium chloride (KCl) and hydrogen chloride (HCl) differ significantly due to the nature of their bonds. Potassium chloride is an ionic compound consisting of potassium (K+) ions and chloride (Cl−) ions. In its Lewis structure, there are no shared electrons; instead, the potassium atom donates an electron to the chloride atom, resulting in a full outer shell for both ions. The potassium ion is typically represented as a K+ with no dots around it, while the chloride ion is represented as a Cl− with eight dots surrounding it to indicate a full valence shell.
On the other hand, hydrogen chloride is a covalent compound where the hydrogen (H) and the chlorine (Cl) share a pair of electrons, demonstrated in its Lewis structure by a single line (or a pair of dots) between the H and Cl atoms, where each atom contributes one electron to the bond. The chlorine atom also has three pairs of lone electrons that are not involved in the bond, represented by three additional pairs of dots around the Cl atom.
Due to these differences in bonding, the ionic forces in KCl lead to a crystalline solid structure at room temperature, while HCl, which consists of discrete covalent molecules, forms a gaseous compound under similar conditions.
The number 1,645.6 expressed in scientific notation equals what?
Answer : The number in scientific notation will be, [tex]1.6456\times 10^3[/tex]
Explanation :
Scientific notation : It is defined as the way or representation of expressing the number that are too big or too small that is written in the decimal form. That means always written in the power of 10 form.
For example : 8000 is written as, [tex]8\times 10^3[/tex] and 0.0008 is written as, [tex]8\times 10^{-4}[/tex]
As we are given that the number is, 1645.6
This number is written in scientific notation as, [tex]1.6456\times 10^3[/tex]
Therefore, the number in scientific notation will be, [tex]1.6456\times 10^3[/tex]
Is iced tea with no ice a homogenuous or a heterogenuous mixture? ...?
Iced tea with no ice is a homogeneous mixture. This is because it has a uniform composition and properties throughout, meaning that you can't distinguish between the different parts of the mixture.
Explanation:When considering whether a substance is a homogeneous or heterogeneous mixture, it's important to look at its physical characteristics. Iced tea with no ice is an example of a homogeneous mixture. Despite the misleading name, the absence of ice does not change the nature of the substance. A homogeneous mixture is defined as a mixture that has uniform composition and properties throughout. This means that you can't distinguish between the different parts of the mixture. Since all portions of the tea mixture are the same, it meets this criterion. On the other hand, a heterogeneous mixture has different compositions and properties in different parts of the mixture.
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Which element is probably most like carbon
an ecologist who is studying the mineral requirements and daily water intake of a plant species is studying
Final answer:
An ecologist studying plant mineral requirements and water intake is engaging in ecology, a sub-discipline of biology concerned with how organisms interact with their environment and their adaptations for survival.
Explanation:
An ecologist who is studying the mineral requirements and daily water intake of a plant species is focused on the field of biology, particularly the sub-discipline of ecology. This field of study is concerned with the physiological, morphological, and behavioral adaptations that allow organisms to survive in specific habitats. By analyzing these factors, ecologists can predict the needs and sustainability of various species within their ecosystems. For instance, field studies may include collecting data in natural environments on various organisms, while laboratory studies could involve analyzing samples or data gathered in the field or applying mathematical models to predict future outcomes. Ecologists not only conduct research but also work in education, policy advisory, and conservation management, often requiring a broad background in the physical sciences and proficiency in mathematics and statistics.
Final answer:
An ecologist studying a plant's mineral and water needs is engaging in biological research within the field of ecology, at the organism level of ecological study. Their work contributes to various societal needs and typically requires an undergraduate degree in the natural sciences.
Explanation:
Understanding Ecological Study in Biology
An ecologist studying the mineral requirements and daily water intake of a plant species is conducting research that falls within the discipline of biology, particularly within the subdivision of ecology. Ecology is a broad field that examines the relationships between organisms and their environments, including the interactions they have with other species and the non-living parts of their ecosystems. In studying a plant's mineral requirements and water intake, an ecologist engages in research at the organism level, which can contribute vital information for understanding the overall health and functioning of ecological systems.
Ecological research can occur both in natural environments (field studies) and controlled lab settings. Field studies might involve observations and data collection in a plant's natural habitat, whereas laboratory studies could involve controlled experiments to determine the specific mineral and water needs of a plant. Additionally, ecologists use various scientific methods and tools, including computer modeling, to analyze and predict ecological outcomes.
Ecologists contribute to many aspects of human society by managing natural resources, advising on policy, and educating the public. To become an ecologist, one typically pursues an undergraduate degree in a natural science, sometimes followed by specialized training or an advanced degree, acquiring a solid foundation in mathematics and statistics along the way.
Why do you think the transition metals are 10 columns wide?
The transition metals are 10 columns wide on the periodic table because each d subshell can hold up to 10 electrons. This configuration leads to a variety of properties, as shown by the diverse reactivity and color of compounds among transition metals.
Explanation:
The transition metals are 10 columns wide on the periodic table due to the configuration of their electrons, specifically in their d orbitals. Each d subshell can accommodate up to 10 electrons, structured as 5 sets of paired electrons. This is connected to the arrangement of the transition metals in the periodic table, which are organized based on electron configuration.
The transition metals, as partially filled d orbitals, are located in the d-block of the periodic table. They vary widely in terms of reactivity, with some being very active metals like scandium and iron, while others being almost inert, such as the platinum metals.
The transition metals exhibit a variety of properties due to their complex valence shells. Because these elements have several different stable oxidation states, electron transitions in these elements can correspond with absorption of photons in the visible spectrum, causing a variety of colored compounds.
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Consider the balanced equation below.
8H2 + S8 ---> 8H2S
Based on the mole ratios, what can most likely be predicted?
1 mol of hydrogen will react with 1 mol of sulfur.
8 mol of hydrogen will react with 1 mol of sulfur.
8 mol of hydrogen will react with 8 mol of sulfur.
16 mol of hydrogen will react with 8 mol of sulfur.
Answer : The correct option is, (2) 8 mole of hydrogen will react with 1 mole of sulfur.
Explanation :
The balanced chemical equation is,
[tex]8H_2+S_8\rightarrow 8H_2S[/tex]
By the stoichiometry we conclude that, 8 moles of hydrogen react with 1 mole of sulfur to give 8 moles of hydrogen sulfide.
Hence, the correct options is, (2) 8 mole of hydrogen will react with 1 mole of sulfur.
What volume of 0.140 HCl is needed to neutralize 2.58 of Mg(OH)2
? ...?
Final answer:
The volume of HCl needed to neutralize a given amount of Mg(OH)₂ can be found by first writing the balanced chemical equation, determining the moles of Mg(OH)₂, calculating the moles of HCl required, and then using the molarity of the HCl solution to find the necessary volume.
Explanation:
To calculate the volume of HCl needed to neutralize a certain amount of Mg(OH)₂, we first need to write the balanced chemical equation for the reaction:
Mg(OH)₂ + 2 HCl -> MgCl₂ + 2 H₂O
From the equation, we see that it takes 2 moles of HCl to neutralize 1 mole of Mg(OH)₂. Say we calculate the moles of Mg(OH)₂ using its molar mass, then we can determine the moles of HCl required. After that, using the molarity of the HCl solution, we can find the volume of HCl needed.
For example, assuming we have x moles of Mg(OH)₂:
Moles of HCl required = 2x moles
Volume of HCl = Moles of HCl / Molarity of HCl solution
The volume calculated will give us the answer to how much HCl is required to neutralize the Mg(OH)₂.
The emission spectrum of hydrogen shows discrete, bright, colored lines. Which characteristic of the Bohr model is best supported by this observation?
a.Energy is released when an electron moves to a higher energy level.
b.Smaller atoms have fewer spectral lines than larger atoms.
c.The energy of an electron increases with distance from the nucleus.
d.Electrons cannot exist in locations other than in specific orbits.
Answer is: d.Electrons cannot exist in locations other than in specific orbits.
According to the Bohr model of the atom:
1. Energy levels of electrons are discrete (certain discrete values of energy)., that is why hydrogen shows discrete, bright, colored lines.
2. Electrons orbit the nucleus in orbits that have a set size and energy.
3. Electrons can jump from one energy level to another, absorbing or emitting electromagnetic radiation with a frequency ν (energy difference of the levels).
hy did dr. tyson decide to exclude pluto from the exhibits of planets
Help meh plz!!!
Which of these systems is responsible for removing waste?
A.endocrine system
B.lymphatic system
C.digestive system
D.excretory system
is AgOH aqueous or a solid?
Answer : AgOH is a solid.
Explanation;
AgOH can be produced from the reaction between NaOH(aq) and AgNO₃(aq). The balanced reaction equation is
NaOH(aq) + AgNO₃(aq) AgOH(s) + NaNO₃(aq)
AgOH is a brown color precipitate which has a Ksp value as 6.8 x 10⁻⁹. The molecular weight of AgOH is 124.88 g/mol.
Silver Hydroxide (AgOH) is generally a solid at room temperature, but its state can change under different conditions. It is not typically found in aqueous form.
Explanation:In the field of Chemistry, AgOH, also known as Silver Hydroxide, is considered to be a solid at room temperature. Silver Hydroxide is an unstable compound that decomposes easily into its constituent water and silver oxide. Hence, it is not typically found in aqueous (dissolved in water) form. However, it's important to understand that its state can change under different conditions such as temperature and pressure.
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