Answer:
The correct answer is 15.54 kJ per degree C.
Explanation:
The enthalpy change for one mole of a substance, which combines or burns with the oxygen under the standard conditions, that is, at 25 degree C and 1 bar pressure is known as the standard molar enthalpy of combustion. The amount of heat transferred can be calculated by using the formula, q = mcΔT -------------(i)
Here q is the amount of heat transferred, c is the specific heat, ΔT is the change in temperature, and m is the mass of the substance. As in case of bomb calorimeter, mass if considered constant, thus, for calorimeter the equation mentioned will become, q = cΔT ---- (ii)
The standard molar enthalpy of combustion for carbon is -393.5 kJ/mol, that is, -393.5 kJ per mole of heat is generated by burning one mole of carbon. The molecular mass of carbon is 12 gram per mole.
Thus, the number of moles of carbon equivalent to 0.562 grams of carbon can be determined as,
Number of moles of carbon = mass / molecular mas
= 0.562 grams / 12 gram per mole
= 0.047 mol
The heat generated by burning 0.562 grams or 0.047 mole will be,
q = ΔH° × number of moles
= (-393.51 kJ/mol) × 0.047 mol
= -18.49 kJ, the negative sign shows that the heat is produced.
To find heat capacity of calorimeter, put the value of q as -18.49 kJ, for ΔT as (27.93 °C - 26.74 °C) in the equation (ii)
18.49 kJ = c × (27.93 - 26.74)
c = 18.49 kJ/1.19 °C
c = 15.54 kJ/°C
How many significant figures are in 0.08260 L? 4 5 6
Answer:
5
Explanation:
Count the digits after the first non zero number, any number after that (even zero) counts.
Hope that helped!!! k
Answer:
[tex]\boxed{4}[/tex]
Explanation:
[tex]\sf Leading \ zeros \ are \ not \ significant.[/tex]
[tex]\sf Trailing \ zeros \ are \ significant.[/tex]
[tex]\sf Non\ zeros \ are \ significant.[/tex]
[tex]0.08260 \sf \ has \ 4 \ significant \ figures.[/tex]
Which of the following is NOT a product of the electrolysis of NaCl? A. Chlorine gas B. None of these C. Hydrogen gas D. Oxygen gas
Answer:D. Oxygen gas
Explanation: because the experiment showed
A sample of copper is heated to 100°C and placed into a calorimeter containing 50 g of water at 25°C after a few minutes the final temperature of the system reaches 40°C how much heat in joules was released by the copper Sample
Answer:
Heat = 3138J
Explanation:
In the system, the sample of Copper is releasing heat that produce the increasing in the temperature of water.
Using the equation of calorimeter, we can find the heat released for the sample of copper (The same that is absorbed for the water):
Q = C×m×ΔT
Where Q is heat, C is specific heat (For water: 4.184J/molK), m is the mass of water (50g) and ΔT is change in temperature of water (40°C-25°C = 15°C)
Replacing:
Q = 4.184J/molK×50g×15°C
Q = 3138J is the heat released for the sample of Copper (The same absorbed for the water).
Answer:
heat=3138j
Explanation:
In the system, the sample of Copper is releasing heat that produce the increasing in the temperature of water.
Using the equation of calorimeter, we can find the heat released for the sample of copper (The same that is absorbed for the water):
Q = C×m×ΔT
Where Q is heat, C is specific heat (For water: 4.184J/molK), m is the mass of water (50g) and ΔT is change in temperature of water (40°C-25°C = 15°C)
Replacing:
Q = 4.184J/molK×50g×15°C
Q = 3138J is the heat released for the sample of Copper (The same absorbed for the water).
Potatoes are cut into many parts, making sure that each part has at least one eye (bud). Each piece of potato will usually grow into a new potato plant. Will a new potato plant grow, if planted only with the eye? A. Yes, a full new potato plant can grow from it. B. Yes, but the new plant will take a slightly longer time to germinate. C. No, a new potato plant will not grow because the food needed for germination comes from the potato piece. D. No, a new potato plant will not grow because the leaves emerge only from the potato piece.
Answer:
b
Explanation:
the eye is the most important so it would grow but it will take some time because if we plant it with piece it has some food
Hi can someone help me with completing the word equation and writing a balanced chemical equation with state symbols
Answer:
Sodium hydroxide + ammonium chloride — Sodium chloride + ammonia gas + water
Explanation:
NaOH + NH4Cl — NaCl + NH3 + H2O
In the image above the ruler is measuring in centimeters. The blue cylinder falls somewhere between 2.7cm and 2.8cm according to the ruler. Since we can estimate the last digit I would say that the length of the cylinder is 2.76cm. Since I am estimating any number 2.72cm or 2.78cm could also be correct.
Why would 2.755 not be a correct measurement according to estimating the last digit?
Answer:
The answer is below
Explanation:
Resolution is the smallest unit of measurement that can be measured by a measuring instrument. Each point on the ruler is 0.1 cm and the difference between any two points, about 0.01 cm cam be measured. The minimum measurement (resolution) that can be measured by the ruler is 0.01 cm (two decimals), therefore it cannot measure up to three decimal places such as numbers like 2.755.
3.Identifica en tu casa 2 elementos en donde sea evidente la elasticidad y dos elementos en los que se manifieste poco y has una pequeña descripción de estos elementos y lo que le permite o no ser evidentemente elásticos
Answer:
Objetos elásticos: forma de cama y neumático de ciclo.
Objetos no elásticos: muebles y cuchara
Explicación:
Dos materiales elásticos que están presentes en las casas son forma y neumático de ciclo y dos materiales no elásticos como muebles y cuchara. Los materiales elásticos son aquellos que muestran alguna deformación en su forma al aplicar fuerza y al eliminar la fuerza, recupera su forma original, mientras que los materiales no elásticos son duros y no pueden cambiar su tamaño y forma.
CH4 + 2O2 → CO2 + 2H2O In the chemical reaction, if 10 moles of H2O are produced, moles of CO2 are also produced
Answer:
The correct answer is 5 moles of CO2 are produced.
Explanation:
The given reaction:
CH₄ (g) + 2O₂ (g) ⇔ CO₂ (g) + 2H₂O (g)
The given reaction is an illustration of a combustion reaction. Any reaction in which a substance is burnt in excess of oxygen to generate water and carbon dioxide is termed as a combustion reaction. From the given equation, it is clear that the moles of the formation of the products are in the ratio 1: 2, that is, if 10 moles of H₂O is produced, the production of 5 moles of CO₂ will be produced.
Let us multiply, the given equation with 5 we get,
5CH₄ + 10O₂ ⇔ 5CO₂ + 10H₂O
Hence, it is clear that with the formation of 10 moles of H₂O, formation of 5 moles of CO₂ will also take place.
1. Which material had the highest rate of absorption? What can you conclude about the rate
of absorption in the natural world? How might this influence climate regions?
it might be porous materials
Answer:
Air had the highest rate of absorption. Air absorbs most of the suns heat and sun rays and air can move to different areas which are warm and colder.
Explanation:
Other than carbon's ability to form four covalent bonds, what is another reason that carbon can form so many compounds? its small size the ability to change shape the ability to form a diatomic molecule the ability to split its electrons
Answer: its small size
Explanation:
Why is particle size the main parameter used in selecting a mechanical phase-separation device?
Answer:
This is because mechanical phase-separation device such as filtration, centrifugation etc operate according to the unique particle size feature in which they are designed to separates.
The process of centrifugation separates particles of size range between 0.1 μm to 5.0 μm efficiently.
The process of filtration however varies as there are different types of pore sizes which covers a wide range of particle sizes.
Which of these factors will cause a solid solute to dissolve faster?
Answer:
Heat
Explanation:
Higher temperatures cause solid solutes to dissolve at a faster rate than normal
Answer:
Higher temperature
Explanation:
A botanist measures a plant growth at 3cm over a two week period. The information she gathers is called.
Answer:
The correct answer is quantitative data.
Explanation:
The value of data in the form of numbers of counts where each set of data exhibits a specific numerical value associated with it is termed as quantitative data. This information refers to any quantifiable knowledge, which can be used for statistical analysis and mathematical calculations so that decisions of real-life can be taken based on the mathematical outcomes. The quantitative data is used to find the solutions of the queries like how often, how much, or how many.
In the given case, a botanist measured the growth of the plant for two weeks, and the outcome came in the form of numerical value. Thus, the knowledge she collected is known as quantitative data.
A student is worried about determining if a chemical is radioactive. Which
section of the SDS would the student refer to?
Product Information
Fire Fighting Methods
Physical and Chemical Properties
Hazards Identification
Answer:
Hazards Identification
Explanation:
A safety data sheet, SDS, is an informational document provided by the manufacturer or importer of a hazardous chemical detailing the chemical, physical, health, and environmental health hazards associated with the chemical as well as safety precautions in handling the chemical.
Some of the sections in the SDS include:
Product Information: It identifies the chemical as well as its recommended uses. The contact information of the manufacturer is also provided.
Fire fighting methods: It gives measures and guidelines necessary for fighting a fire caused by the chemical.
Physical and chemical properties: states the physical and chemical properties of the chemical substance such as: appearance, odor, pH, melting/freezing point, boiling point and boiling range, flammability, etc.
Hazards identification: states the hazards of the chemical and the necessary warnings regarding the hazards. Some of the information provided include: hazard classification of the chemical (for example flammable liquid, oxidizing gases,explosives, etc), signal word, hazard statement (for example radioactive), pictograms, precautionary statements, etc.
From the above information provided, the student should refer to the hazards identification section.
which statement best describes a mole? it is 12 units of a given substance. it contains 6.02 1023 grams of sodium chloride. it is the mass of 12 carbon atoms. it contains 6.02 1023 particles of a given substance.
Answer:
The correct option is;
It contains 6.02 × 10²³ particles of a given substance
Explanation:
A mole of substance is the standard scientific unit of measurement for the quantity of the substance which is made up of a large number of small particles such as molecules, ions, atoms, electrons or other entities.
The General Conference on Weights and Measures defines the mole as the amount of a substance that contains 6.02214076 × 10²³ units of entities
The number 6.02214076 × 10²³, is also known as Avogadro's number.
The statement which correctly describes the mole is; it contains 6.02 × 10^23 particles of a given substance.
The mole refers to the amount of substance that contains the same number of elementary entities as 12 g of carbon - 12. According to Avogadro's law, the number of elementary entities in a substance is 6.02 × 10^23. These elementary entities could be atoms, ions, molecules etc.
Therefore, the statement which correctly describes the mole is; it contains 6.02 × 10^23 particles of a given substance.
Learn more: https://brainly.com/question/12108425
What is an empirical formula?
Answer:
a formula giving the proportions of the elements present in a compound but not the actual numbers or arrangement of atoms.
Hope this helped!!!
Answer:
Empirical formulas show the simplest whole-number ratio of atoms in a compound
Explanation:
why is carbon iv oxide used in fire extinguishers
Answer:
Carbon dioxide extinguishes work by displacing oxygen, or taking away the oxygen element of the fire triangle. The carbon dioxide is also very cold as it comes out of the extinguisher, so it cools the fuel as well.
5 (01.01 LC)
Which of the following would be a warning sign that information about a weight loss medication is not reliable science?
Answer:
The scientists and all test subjects involved in the investigation work for the company that sells the medication.
Explanation:
The options are as below:
A. The investigation compared a group that took the medication to a control group that did not take the medication.
B. The scientists and all test subjects involved in the investigation work for the company that sells the medication.
C. The weight loss medication worked for 95 out of the 100 test subjects, while only 15 of the 100 control subjects lost weight.
D. The weight loss results were replicated by scientists conducting a study at an independent institution
The correct option would be that the scientists and all test subjects involved in the investigation work for the company that sells the medication.
When selecting the test subjects for research, the selection must be as random as possible so as to ensure an unbiased outcome and increase the reliability of the research.
Limiting the test subjects to those that work in the company that sells the medication will generally reduce the reliability of the outcome because of element of bias that can be introduced either knowingly or unknowingly.
The test subjects must have been selected from the general population of target users for the medication and not limited to just the employees of the manufacturing company.
Correct option: B
explain how sodium and calcium react with water. explain with equations
Reaction of sodium with water
Sodium metal reacts rapidly with water to form a colourless solution of sodium hydroxide (NaOH) and hydrogen gas (H2). The resulting solution is basic because of the dissolved hydroxide. The reaction is exothermic. During the reaction, the sodium metal may well become so hot that it catches fire and burns with a characteristic orange colour. The reaction is slower than that of potassium (immediately below sodium in the periodic table), but faster than that of lithium (immediately above sodium in the periodic table).
2Na(s) + 2H2O → 2NaOH(aq) + H2(g)
Balance the equation: "Sodium oxide reacts with water to form sodium hydroxide and hydrogen." I can't find the correct coefficients to balance the equation. I have written my unbalanced equation in the file attached.
Answer:
So, sodium oxide + water = sodium hydroxide + hydrogen is written Na2O+H2O-->NaOH+H.
To balance the equation it should read NaO+H2O-->2NaOH
Explanation:
Na2O+H2O-->2NaOH+0H2.......the 0H2 is dropped because there is no value
The correct balance of equation will be
Na2O + H2O - - > 2NaOH
What is a balanced chemical equation?A chemical equation where the number of atoms on both the reactant side and the product side of the reaction are equal is called a balanced chemical equation.
In a balanced chemical equation, not only the number of atoms but the charge and the mass is the same on both sides of the equation.
A chemical equation needs to be balanced to validate the law of conservation of mass. The law of conservation of mass states that the 'mass can neither be created nor destroyed in a chemical reaction'.
If the chemical equation is not balanced, it will go against the fundamental law of law of conservation of mass.
Thus, the chemical equations need to be balanced.
Therefore to balanced the given chemical equation, we equate the number of atoms on both the reactant and the product side of the reaction.
It will be written as
Na2O + H2O - - > 2NaOH
Read more about balanced chemical equations, here
https://brainly.com/question/8062886
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begging u to answer Which is not an inter molecular force? Select one: a. Inter atomic bonds b. van der waals forces c. hydrogen bonds
Answer:
a-Interatomic bonds
Explanation:
First of all, it is not a force. Let alone be molecular force.
What element is depicted by the following electron configuration:
you can determine this by
adding the numbers of the sub-shells, 2+2+6+2+4=16the number on the last sub-shell, 4 means on the 4th main groupthe 3 before 3p4, tells us on the 3rd period, so the answer is Sulphur.6th edition before we begin, let's first establish an understanding of basic terminology. it may be harder than you think to clearly define what is a chemical versus a chemical reaction. to help us better differentiate between closely related terms, review the words listed here. sort each of the words into the three categories: contains chemicals, chemical reaction, or neither.
Answer:
Chemicals are substances in any form of matter with a chemical composition and property. Chemical reaction involves the combination of two or more different atoms chemically combined together, which are not easily separated.
Explanation:
CHEMICALS
Vitamin [tex]B_{1}[/tex]proteingraniteorangesCHEMICAL REACTIONS
neutralisationcombustionbleachingphotosynthesisNEITHER
sunlightheatrainbowWhich of the following is NOT the property of a non-metal? A. Non-rigid structure B. Not ductile C. Low density D. Malleable
Answer:
The answer is D.
Explanation:
Malleable is the property of metal not non-metal.
Answer:
malleable
Explanation:
because a non metal cannot be harmmed into sheetsH2SO4 is also called
a. king of acid
b. king of chemical
c. blue vitriol
d. Antacid
Answer:
[tex]\huge\boxed{King\ of \ Acid}[/tex]
Explanation:
H2SO4 (also called sulfuric acid) is also called King of Acids. It is a highly reactive acid.
Answer:
[tex]\large \boxed{\mathrm{a. \ king \ of \ acid }}[/tex]
Explanation:
[tex]\sf H_2SO_4[/tex] or sulfuric acid is known as the king of acid. It is a very reactive acid and is a strong acid in general.
Which are the physical properties of water
Answer:
Some physical properties of water:
It is odorless.It could appear as a white crystalline solid in solid form, a transparent gas with almost no color but a slight hint of blue in liquid form, or a colorless gas in gas form.It has a melting point of 0°C and a boiling point of 100°C.Its density (at 25°C) is about 0.99701 grams/cm³.It has a viscosity of 0.8903 centi-poise.Of course, there are many more but these are some common ones.
Chemistry is often called the __________ science because it involves the study of the materials in the universe and the changes these materials undergo
Answer:
Central
Explanation:
Chemistry is often called the central science because of connects the physical sciences, life sciences and applied sciences.
Chemistry is the study of matter and changes undergone by matter. This makes chemistry to occupy a central place in many scientific disciplines including medicine, engineering, pharmacy, geology etc. Basic knowledge of chemistry is usually required by experts in these disciplines.
Select the items that describe a chemical property below. Choose THREE correct answers.
1:Heated iron can be hammered into a sword.
2:A handwarmer gets warm when it is opened and exposed to air.
3:Propane ignites to heat a grill.
4:Cotton is dyed red to make a dress.
5:A cylinder in an engine uses gasoline to move pistons.
6:Maple syrup is thicker than water.
Answer:
2:A handwarmer gets warm when it is opened and exposed to air.
3:Propane ignites to heat a grill.
4:Cotton is dyed red to make a dress.
Explanation:
The definition of a chemical property is when a property of characteristic of a substance that is observed during a reaction in which a chemical has been changed
You are pushing a box with 20 N of force that has
a mass of 10 kg, solve for acceleration
Answer:
Force=mass ×acceleration.
20=10×acceleration.
20=10a.
a=2m/s^2.
Qu
What can you determine about the feasibility of a
reaction if the enthalpy is positive and the entropy is
negative?
1
A. The reaction will usually occur because it is unlikely the
entropy will be greater than the enthalpy.
B. The Gibbs energy will always be positive, and the reaction will
never be feasible.
C. The Gibbs energy will always be negative, and the reaction will
always be feasible.
D. The reaction could be feasible above a certain temperature,
Reset Selection
Answer:
B. The Gibbs energy will always be positive, and the reaction will
never be feasible.
Explanation:
The relationship between gibbs fee energy, G, enthalpy, H and Entropy, S is given as;
ΔG = ΔH - TΔS
If enthalpy is positive and entropy is negative, it means that we are going t always have a positive value for the gibbs free energy.
This means the correct option is option B.
