The standard enthalpy of formation, also known as the standard heat of formation, is a thermodynamic property that quantifies the heat change associated with …At 25°C, the standard enthalpy change (ΔH°) is −187.78 kJ/mol, and the absolute entropies of the products and reactants are: S°(H 2 O 2) = 109.6 J/(mol•K), ... The standard free energy of formation of a compound can be calculated from the standard enthalpy of formation ...The enthalpy change for a formation reaction is called the enthalpy of formation.. The subscript f is the clue that the reaction of interest is a formation reaction. Thus, for the formation of FeO(s): Note that now we are using kJ/mol as the unit because it is understood that the enthalpy change is for one mole of substance.In today’s competitive job market, it is crucial to have a well-crafted curriculum vitae (CV) that stands out from the crowd. For job seekers in Europe, the Europass CV has become ...Standard enthalpy of formation ΔH f ° is an enthalpy change for a reaction in which exactly one mole of a pure substance is formed from free elements in their most stable states under standard conditions. These values are especially useful for computing or predicting enthalpy changes for chemical reactions that are impractical or dangerous to ...The standard enthalpy of formation of any element in its standard state is zero by definition. For example, although oxygen can exist as ozone (O 3 ), atomic oxygen (O), and molecular oxygen (O 2 ), O 2 is the most stable form at 1 atm pressure and 25°C.The boldfaced values are the coefficients and the other ones are the standard enthalpy of formation for the four substances involved. Since oxygen is an element in its standard state, its enthalpy of formation is zero. Doing the math gives us ΔH comb o = −1367 kJ/mol of ethyl alcohol. Standard Enthalpies of Formation ... All standard state, 25 °C and 1 bar (written to 1 decimal place). ... enthalpy-qr-20161107 Author: Alan D. Earhart A standard enthalpy of formation Δ H f ° Δ H f ° is an enthalpy change for a reaction in which exactly 1 mole of a pure substance is formed from free elements in their most stable states under standard state conditions. These values are especially useful for computing or predicting enthalpy changes for chemical reactions that are ... 1, 2] enthalpy of formation based on version 1.122 of the Thermochemical Network This version of ATcT results was partially described in Ruscic et al. [], and was also used for the initial development of high-accuracy ANLn composite electronic structure methods [].Standard Enthalpy of Formation. Standard enthalpy of formation is defined as the enthalpy change when one mole of a compound is formed from its elements in their most stable state of aggregation (stable state of aggregation at temperature: 298.15 K, pressure: 1 atm). For example formation of methane from carbon and hydrogen: Jan 9, 2020 ... Click here:point_up_2:to get an answer to your question :writing_hand:calculate the standard enthalpy of formation of ch3ohi from the ...Jan 9, 2020 ... Click here:point_up_2:to get an answer to your question :writing_hand:calculate the standard enthalpy of formation of ch3ohi from the ...Enthalpy of formation of liquid at standard conditions Data from NIST Standard Reference Database 69: NIST Chemistry WebBook The National Institute of Standards and Technology (NIST) uses its best efforts to deliver a high quality copy of the Database and to verify that the data contained therein have been selected on the basis of sound ... The experimental value for this enthalpy change can be calculated from standard enthalpies of formation. It is –802.4 kJ mol –1. The discrepancy is due to the unavoidable use of mean bond enthalpies in the calculation. This page titled 10.9: ...The standard deviation of the mean for energy equivalent is 0.01%. 2. The value of standard molar enthalpy of formation of vanillin in the crystalline state at 298.15 K was clarified by using bomb calorimetric method, and was found to …2C(s) + 3H2(g) → C2H6(g) 2 C ( s) + 3 H 2 ( g) → C 2 H 6 ( g) Exercise 7.7.2 7.7. 2. Write the equation for the formation of CaCO3(s) CaCO 3 ( s). Answer. The enthalpy change for a formation reaction is called the enthalpy of formation and is given the symbol Δ H f. The subscript f is the clue that the reaction of interest is a formation ...The standard enthalpy of formation of CO 2 (g) is −393.5 kJ/mol. This is the enthalpy change for the exothermic reaction: C (s, graphite) + O 2 (g) → CO 2 (g) ΔH° f = ΔH° 298 = -393.509 kJ. starting with the reactants at a pressure of 1 atm and 25 °C (with the carbon present as graphite, the most stable form of carbon under these ...The notion of heat of formation, or sometimes it's change in enthalpy of formation. So the way they talk about it is, the change in enthalpy of formation. And ...The "standard molar enthalpy of formation", DeltaH_"f"^@, is the enthalpy associated with the formation of 1*mol of substances from its constituent elements in their standard states under standard conditions..... H_2(g) + 1/2O ... The #"standard molar enthalpy of formation"#, ...The standard enthalpy of formation or "standard heat of formation" of a compound is the change of enthalpy that accompanies the formation of 1 mole of a substance in its standard state from its constituent elements in their standard states (the most stable form of the element at 100 kPa of pressure and the specified temperature, usually 298 K ...The standard enthalpy of formation of CO 2 ( g) is −393.5 kJ/mol. This is the enthalpy change for the exothermic reaction: C(s)+O2(g) CO2(g) ΔH f° = ΔH ° = −393.5kJ /mol C ( s) + O 2 ( g) C O 2 ( g) Δ H f ° = Δ H ° = − 393.5 k J / m o l. starting with the reactants at a pressure of 1 atm and 25 °C (with the carbon present as ... Standard enthalpies of formation are calculated using ab initio (CBS‐QB3) and DFT calculations (B3LYP, M06, APFD). The reaction of A2• with ³ O 2 opens six ...May 3, 2023 · The standard enthalpy of formation of CO 2 ( g) is −393.5 kJ/mol. This is the enthalpy change for the exothermic reaction: C(s) + O 2(g) CO 2(g) ΔH ∘ f = ΔH ∘ 298 = − 393.5kJ. starting with the reactants at a pressure of 1 atm and 25 °C (with the carbon present as graphite, the most stable form of carbon under these conditions) and ... The experimental value for this enthalpy change can be calculated from standard enthalpies of formation. It is –802.4 kJ mol –1. The discrepancy is due to the unavoidable use of mean bond enthalpies in the calculation. This page titled 10.9: ...Enthalpy change is the standard enthalpy of formation, which has been determined for a vast number of substances. In any general chemical reaction, the reactants undergo chemical changes and combine to give products. It …The standard enthalpy of formation for an element in its standard state is ZERO!!!! Elements in their standard state are not formed, they just are. So, ΔH f o for C (s, graphite) is zero, but the ΔH f o for C (s, diamond) is 2 kJ/mol. That is because graphite is the standard state for carbon, not diamond. Practice Problems. Standard enthalpy change of formation (data table) These tables include heat of formation data gathered from a variety of sources, including the primary and secondary …The standard enthalpy of formation of CO 2 ( g) is −393.5 kJ/mol. This is the enthalpy change for the exothermic reaction: starting with the reactants at a pressure of 1 atm and 25 °C (with the carbon present as graphite, the most stable form of carbon under these conditions) and ending with one mole of CO 2, also at 1 atm and 25 °C. All enthalpies of formation listed below for selected substances are defined at the standard state of 298.15 K and 1 bar (100 kPa). Standard Thermodynamic Properties for Selected Substances SubstanceThe standard enthalpy of formation is a measure of the energy released or consumed when one mole ... In today’s fast-paced business environment, human resources (HR) departments play a critical role in ensuring the smooth functioning of organizations. Having policies documented in...Examples of enthalpy changes include enthalpy of combustion, enthalpy of fusion, enthalpy of vaporization, and standard enthalpy of formation. The standard enthalpy of formation, \(ΔH^\circ_\ce{f}\), is the enthalpy change accompanying the formation of 1 mole of a substance from the elements in their most stable states at 1 bar (standard state).III. For any substance at any particular temperature, we define the standard enthalpy of formation as the enthalpy change for a reaction in which the product is one mole of the substance and the reactants are the compound’s constituent elements in their standard states. For water at –10 C, this reaction is. H2(g, −10 C, 1 bar) + 1 2 O2(g ...Mar 10, 2023 · The standard enthalpy of formation of CO 2 ( g) is −393.5 kJ/mol. This is the enthalpy change for the exothermic reaction: C(s) + O 2(g) CO 2(g) ΔH ∘ f = ΔH ∘ 298 = − 393.5kJ. starting with the reactants at a pressure of 1 atm and 25 °C (with the carbon present as graphite, the most stable form of carbon under these conditions) and ...Enthalpy of combustion of solid at standard conditions: Δ f H° solid: Enthalpy of formation of solid at standard conditions: Data from NIST Standard Reference Database 69: NIST Chemistry WebBook; The National Institute of Standards and Technology (NIST) uses its best efforts to deliver a high quality copy of the Database and to verify that ...The standard enthalpy of formation, also known as the standard heat of formation, is a thermodynamic property that quantifies the heat change associated with …Dear Lifehacker,III. For any substance at any particular temperature, we define the standard enthalpy of formation as the enthalpy change for a reaction in which the product is one mole of the substance and the reactants are the compound’s constituent elements in their standard states. For water at –10 C, this reaction is. H2(g, −10 C, 1 bar) + 1 2 O2(g ...Dear Lifehacker,The standard enthalpy of the formation of nitrogen dioxide is +33.2 kJ/mol. It means that 33.2 kJ of energy is required to form one mole of NO 2 from ½ mole of nitrogen (N 2) and one mole of oxygen (O 2) at 1 atmospheric pressure and 25 ˚C. The reaction is endothermic. Below is a table of standard enthalpy of formation for many common ... Learn the definition, classification, and calculation of enthalpy, a state function that measures the heat flow in or out of a system. Find out how to use Hess's law and …Hess's law can be used to calculate enthalpy changes that are difficult to measure directly. In this video, we'll use Hess's law to calculate the enthalpy change for the formation of methane, CH₄, from solid carbon and hydrogen gas, a reaction that occurs too slowly to be measured in the laboratory.The standard enthalpy of formation, \(ΔH^\circ_\ce{f}\), is the enthalpy change accompanying the formation of 1 mole of a substance from the elements in their most stable states at 1 bar (standard state). Many of the processes are carried out at 298.15 K. Key Equations \(ΔE=q+w\)Jun 10, 2020 · The standard enthalpy of formation of any element in its most stable form is zero by definition. The standard enthalpy of formation of any element in its standard state is zero by definition. For example, although oxygen can exist as ozone (O 3), atomic oxygen (O), and molecular oxygen (O 2), O 2 is the most stable form at 1 atm pressure and 25°C. Question: Use standard enthalpies of formation to calculate ΔH∘rxn for the following reaction: A. 2H2S (g)+3O2 (g)→2H2O (l)+2SO2 (g) B. CH4 (g)+2O2 (g)→CO2 (g)+2H2O (g) C. C (s)+O2 (g)→CO2 (g) D. CaO (s)+CO2 (g)→CaCO3 (s) Use standard enthalpies of formation to calculate ΔH∘rxn for the following reaction: A. 2H2S (g)+3O2 (g)→ ...Jun 16, 2023 · Let's use these enthalpies of formation to calculate the enthalpy of combustion for 1 mol of methane. The reaction we want is. (2) C H 4 ( g) + 2 O 2 ( g) → C O 2 ( g) + 2 H 2 O ( g) If we reverse a reaction, we change the sign on ΔH, and if we multiply the reaction by a constant coefficient, we multiply ΔH by the same coefficient. The standard enthalpy of formation, Gibbs energy of formation, entropy and molar heat capacity are tabulated for more than hundred organic substances. Sponsored Links ΔH° f : The standard enthalpy of formation at 25°C (298,15 K) for 1 mol of the substance in its given state (g= gas and l= liquide) from its elements in their standard state ... Learn the definition, measurement, and applications of standard enthalpy of formation, the enthalpy change when 1 mol of a substance is formed from its elements. See …Enthalpy of formation of gas at standard conditions: Data from NIST Standard Reference Database 69: NIST Chemistry WebBook; The National Institute of Standards and Technology (NIST) uses its best efforts to deliver a high quality copy of the Database and to verify that the data contained therein have been selected on the basis of sound ...Jun 10, 2020 · The standard enthalpy of formation of any element in its most stable form is zero by definition. The standard enthalpy of formation of any element in its standard state is zero by definition. For example, although oxygen can exist as ozone (O 3), atomic oxygen (O), and molecular oxygen (O 2), O 2 is the most stable form at 1 atm pressure and 25°C. That's why white phosphorus, rather than black, is assumed standard and has zero enthalpy of formation. Share. Cite. Improve this answer. Follow edited May 5, 2017 at 12:43. answered May 5, 2017 at 12:34. Ivan Neretin Ivan Neretin. 31.1k 3 3 gold badges 72 72 silver badges 119 119 bronze badgesEnthalpy of formation of liquid at standard conditions Data from NIST Standard Reference Database 69: NIST Chemistry WebBook The National Institute of Standards and Technology (NIST) uses its best efforts to deliver a high quality copy of the Database and to verify that the data contained therein have been selected on the basis of sound ... Standard Enthalpy of Formation: An Overview As defined by the International Chemical Engineering Society, the standard enthalpy of formation is the change in enthalpy that occurs when one mole of a compound is created from its constituents in their most stable state of aggregation (stable state of aggregation at temperature: 298.15k, pressure: 1 atm).The definition of standard enthalpy of formation is the change in enthalpy when one mole of a substance is formed in its standard state from its constituent elements in their standard state at 298k and 1 atm. Since elements like Oxygen are in their standard state, there is no standard enthalpy of formation to talk about here. Standard Enthalpy of Formation (ΔHof): the enthalpy change associated with the formation of one mole of a substance from its constitute elements, in their standard states.A pure element that is in its standard state has a standard enthalpy of formation equal to zero.. To calculate ΔHof of a reaction, the following formula is used: ΔfHo= …Entropy of solid at standard conditions (1 bar) Δ c H° solid: Enthalpy of combustion of solid at standard conditions: Δ f H° gas: Enthalpy of formation of gas at standard conditions: Δ f H° solid: Enthalpy of formation of solid at standard conditions: Δ r G° Free energy of reaction at standard conditions: Δ r H° Enthalpy of reaction ...Standard enthalpy change of formation (data table) These tables include heat of formation data gathered from a variety of sources, including the primary and secondary …standard enthalpy of formation. change of enthalpy during the formation of 1 mole of the compound from its constituent elements, with all substances in their standard states at 1 bar and 25°C. standard heat of formation; Data type. Quantity. Statements. instance of. Wikidata property for physical quantities.The standard enthalpy of formation of CO 2 ( g) is −393.5 kJ/mol. This is the enthalpy change for the exothermic reaction: C ( s) + O 2 ( g) CO 2 ( g) Δ H f ° = Δ H 298 ° = − 393.5 kJ. starting with the reactants at a pressure of 1 atm and 25 °C (with the carbon present as graphite, the most stable form of carbon under these conditions ... We define the standard enthalpy of formation of any element at any temperature to be zero. In Section 8.6, we find that the enthalpy difference between reactants in their standard states and products in their standard states is readily calculated from the standard enthalpies of formation of the participating substances. As …Enthalpy of formation of gas at standard conditions: Data from NIST Standard Reference Database 69: NIST Chemistry WebBook; The National Institute of Standards and Technology (NIST) uses its best efforts to deliver a high quality copy of the Database and to verify that the data contained therein have been selected on the basis of sound ...Jun 14, 2021 · ΔrHo. and summing the enthalpy changes for the series of steps gives the standard enthalpy change for the reaction: ΔrHo = ΔHcompression + ΔHmixing + ΔHmeasured + ΔHseparation + ΔHexpansion. It turns out that the enthalpy changes for the compression, mixing, separation, and expansion processes are usually small compared to ΔrHo. Dec 13, 2013 ... Standard enthalpies of formation. 493 views · 10 years ago ...more. Jan Jensen. 2.9K. Subscribe. 1. Share. Save.Enthalpy of formation of solid at standard conditions: Data from NIST Standard Reference Database 69: NIST Chemistry WebBook; The National Institute of Standards and Technology (NIST) uses its best efforts to deliver a high quality copy of the Database and to verify that the data contained therein have been selected on the basis of sound ...Oct 10, 2023 · Standard enthalpies of formation are the building blocks of any thermochemical database. In the case of organic compounds, and, in particular, those which contain only carbon, hydrogen, oxygen, and nitrogen, the enthalpies of formation are most commonly derived from combustion calorimetry experiments. For many organic …May 22, 2018 ... Need help in Chemistry? Are you in 9th, 10th, 11th or 12th grade? Then you shall find these videos useful. With an experience of 17 years of ...For oxygen, the standard state is O2 gas. By definition, the standard enthalpy of formation of an element in its standard state is zero. This is because there ...Nov 30, 2011 ... Comments45 ; Using Calorimetry to Calculate Enthalpies of Reaction - Chemistry Tutorial. TheChemistrySolution ; Calculate the standard enthalpy of ...In order to do this we must first become familiar with the idea of a bond enthalpy. ... The experimental value for this enthalpy change can be calculated from standard enthalpies of formation. It is –802.4 kJ mol –1. The discrepancy is due to the unavoidable use of mean bond enthalpies in the calculation.This is similar to how we calculate the enthalpy of a reaction from the standard enthalpies of formation. Notice, however, that S o, unlike ΔH o f and ΔG o f for elements is not zero at 25 °C For example, using the data in an appendix for homonymic data, calculate the standard entropy changes, ΔS for the following reactions at 25°C:May 4, 2023 · The standard enthalpy of formation of CO 2 ( g) is −393.5 kJ/mol. This is the enthalpy change for the exothermic reaction: C(s) + O 2(g) CO 2(g) ΔH ∘ f = ΔH ∘ 298 = − 393.5kJ. starting with the reactants at a pressure of 1 atm and 25 °C (with the carbon present as graphite, the most stable form of carbon under these conditions) and ...Standard Enthalpy of Formation: Define Enthalpy [Click Here for Sample Questions] The term “enthalpy” is specifically used in science and engineering in order to quantify heat and function. At a constant strain, the enthalpy notifies how much heat and effort has been applied or extract from the substance.Dec 26, 2012 · Standard Enthalpies of Formation. As mentioned on the previous page, using Hess' Law makes it possible to calculate many D H's from just a few reactions for which D H is known. Scientists have compiled a long list of standard enthalpies of formation (D H f º) for this purpose. Each D H f º corresponds to a special thermochemical equation with the …Standard Enthalpies of Reaction. Tabulated values of standard enthalpies of formation can be used to calculate enthalpy changes for any reaction involving substances whose \(\Delta{H_f^o}\) values are known. The standard enthalpy of reaction (ΔH rxn) is the enthalpy change that occurs when a reaction is carried out with all reactants and …Selected ATcT [1, 2] enthalpy of formation based on version 1.118 of the Thermochemical Network This version of ATcT results was partially described in Ruscic et al. , and ... Introduction to Active Thermochemical Tables: Several "Key" Enthalpies of Formation Revisited. J. Phys. Chem. A 108, 9979-9997 (2004) [DOI: 10.1021/jp047912y] 2Q 1. Standard molar enthalpy of formation of CO2 is equal to. View Solution. Q 2. Standard molar enthalpy of formation of CO2 is equal to: View Solution. Q 3. The standard molar heats of formation of ethane, CO2 and H 2O(l) are respectively −21.1,−94,1 and −68.3kcal. The standard molar heat of combustion of ethane will be:In order to quantify the enthalpy of reaction for a given reaction, one approach is to use the standard enthalpies of formation for all of the molecules involved. These values describe the change in enthalpy to form a compound from its constituent elements. Subtracting the standard enthalpies of formation for the reactants from the standard ...From what I understand Hydrogen only exists as a monatomic gas at very high temperatures, the Standard enthalpies of formation are given at 1 bar, 298.15 K. enthalpy; hydrogen; Share. Cite. edited Jul 17, 2023 at 23:32. samuelschaefer. asked Apr 18, 2016 at 6:16. samuelschaefer samuelschaefer.Similar to the standard enthalpies of formation, \( (ΔG^\circ_\ce{f})\) is by definition zero for elemental substances under standard state conditions. The approach to computing the free energy change for a reaction using this approach is the same as that demonstrated previously for enthalpy and entropy changes. For the reactionJun 10, 2020 · The standard enthalpy of formation of any element in its most stable form is zero by definition. The standard enthalpy of formation of any element in its standard state is zero by definition. For example, although oxygen can exist as ozone (O 3), atomic oxygen (O), and molecular oxygen (O 2), O 2 is the most stable form at 1 atm pressure and 25°C.
The standard enthalpy of formation (ΔH0f) of a compound is the change in enthalpy that accompanies the formation of 1 mole of a compound from its elements …. Incubus drive lyrics
One Enthalpy of particular use is the Enthalpy of Formation. The Standard enthalpy of formation (ΔH o F) is the heat change that results when one mole of a compound is formed from its elements (in most stable form/natural) at a pressure of 1 atm. The standard enthalpy of formation of any element in its most stable form is zero. Standard Atomization Enthalpies. Before we start talking about Born-Haber cycles, we need to define the atomization enthalpy, \(\Delta H^o_a\). The standard atomization enthalpy is the enthalpy change when 1 mole of gaseous atoms is formed from the element in its standard state. Enthalpy change of atomization is always positive.The standard enthalpy of formation of compound i i, ΔfH −⊖− i Δ f H i − ⊖ −, is the change of enthalpy during the formation of 1 mol of i i from its constituent elements, with all substances in their standard states. The standard pressure is defined at P −⊖− = 100 kPa = 1 bar P − ⊖ − = 100 k P a = 1 b a r. 2 2 There is ...dH = CpdT. And so for a temperature change from T1 to T2. ΔH = ∫T2T2CpdT. Equation 3.5.1 is often referred to as Kirchhoff's Law. If Cp is independent of temperature, then. ΔH = CpΔT. If the temperature dependence of the heat capacity is known, it can be incorporated into the integral in Equation 3.5.1.Jan 16, 2023 · Standard Enthalpy of Formation. Definition: the Standard State; Ionization Reactions; Average Bond Enthalpies; Reaction enthalpies are important, but difficult to tabulate. However, because enthalpy is a state function, it is possible to use Hess’ Law to simplify the tabulation of reaction enthalpies. Hess’ Law is based on the addition of ... May 9, 2021 · The standard enthalpy of formation of any element in its most stable form is zero by definition. The standard enthalpy of formation of any element in its standard state is zero by definition. For example, although oxygen can exist as ozone (O 3), atomic oxygen (O), and molecular oxygen (O 2), O 2 is the most stable form at 1 atm pressure and 25°C.This is similar to how we calculate the enthalpy of a reaction from the standard enthalpies of formation. Notice, however, that S o, unlike ΔH o f and ΔG o f for elements is not zero at 25 °C For example, using the data in an appendix for homonymic data, calculate the standard entropy changes, ΔS for the following reactions at 25°C:The standard enthalpy of formation, , is the enthalpy change accompanying the formation of 1 mole of a substance from the elements in their most stable states at 1 bar (standard state). Many of the processes are carried out at 298.15 K. If the enthalpies of formation are available for the reactants and products of a reaction, the enthalpy ...May 28, 2019 ... The change in enthalpy that takes place when one mole of a compound is formed from its elements, all substances being in their standard states ( ...The standard enthalpy of formation of any element in its standard state is zero by definition. For example, although oxygen can exist as ozone (O 3 ), atomic oxygen (O), …Mar 10, 2023 · The standard enthalpy of formation of CO 2 ( g) is −393.5 kJ/mol. This is the enthalpy change for the exothermic reaction: C(s) + O 2(g) CO 2(g) ΔH ∘ f = ΔH ∘ 298 = − 393.5kJ. starting with the reactants at a pressure of 1 atm and 25 °C (with the carbon present as graphite, the most stable form of carbon under these conditions) and ...The Basics: Glass Formation - Glass formation is a simple process using silica, soda, lime and heat. Learn about glass formation and why you can only see through some objects. Adve...Learn the definition, measurement, and applications of standard enthalpy of formation, the enthalpy change when 1 mol of a substance is formed from its elements. See …By definition, the standard enthalpy of formation of an element in its most stable form is equal to zero under standard conditions, which is 1 atm for gases and 1 M for solutions. …Enthalpy of formation of solid at standard conditions: Data from NIST Standard Reference Database 69: NIST Chemistry WebBook; The National Institute of Standards and Technology (NIST) uses its best efforts to deliver a high quality copy of the Database and to verify that the data contained therein have been selected on the basis of sound ...Apr 23, 2016 · If the standard enthalpy of formation is defined as . the energy change when 1 mole of a substance is formed from its elements in their standard states. and forming chemical bonds is an exothermic process, then does this mean all standard enthalpies of formation are non-positive?The standard enthalpy of formation, also known as the standard heat of formation, is a thermodynamic property that quantifies the heat change associated with …Learn the definition and formula of standard enthalpy of formation, and how to use it to calculate the enthalpy change of any chemical reaction. Watch the video and see examples, ….