A sample of ethanol (C2H6O) has a mass of 0. 2301 g. Complete combustion of this sample causes the temperature of a bomb calorimeter to increase by 1. 33°C. The calorimeter has a mass of 2. 000 kg and a specific heat of 2. 45 J/g•°C. What is the heat of combustion for this sample? kJ.

Taking into account the definition of calorimetry, the mass of the sample is 478.41 grams.

Calorimetry is the measurement and calculation of the amounts of heat exchanged by a body or a system.

Sensible heat is defined as the amount of heat that a body absorbs or releases without any changes in its physical state (phase change).

So, the equation that allows to calculate heat exchanges is:

Q = c× m× ΔT

where Q is the heat exchanged by a body of mass m, made up of a specific heat substance c and where ΔT is the temperature variation.

In this case, you know:

Replacing:

-543 J= 0.227 [tex]\frac{J}{gC}[/tex]× m× (-5 C)

Solving:

[tex]m=\frac{-543 J}{0.227 \frac{J}{gC}x(-5 C)}[/tex]

m=478.41 grams

In summary, the mass of the sample is 478.41 grams.

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Answer:

The ground state represents the lowest-energy state of the atom.

Explanation:

sd

To measure the density of the stone placed in a graduated cylinder let us follow these steps bellow

We know that the formula for density is given as

Given data

Mass = 8gram

Initial Volume of water in cylinder = 25mL

Final Volume of water in cylinder  = 29mL

Hence the volume of the rock  = 29-25 = 4mL

Therefore the density of the rock = 8/4 = 2 g/mL

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Answer:

5 ms2

Explanation:

The acceleration of the ball is 5 ms2.

Acceleration is the rate at which an object's velocity with respect to time changes. It is a vector quantity to accelerate (in that they have magnitude and direction). The direction of the net force acting on an object determines the direction of its acceleration.

The acceleration of the car in its present direction of motion is referred to as a linear acceleration (or tangential acceleration in circular motions), and the passengers on board feel a force pressing them back into their seats as a result.

The acceleration that is used to change direction is referred to as radial acceleration (or centripetal acceleration in circular travels), and the reaction that the passengers feel is a centrifugal force.

Therefore, The acceleration of the ball is 5 ms2.

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Answer:

4. A gene is introduced into salmon to make them grow twice as fast.

Answer: Sodium also floats on the surface, but enough heat is given off to melt the sodium (sodium has a lower melting point than lithium and the reaction produces heat faster) and it melts almost at once to form a small silvery ball that dashes around the surface.

Explanation:

Answer:

hydroxide.

Explanation:

Alkali metals are in group 1 of the Periodic Table. They are on the left of the Periodic Table. These are the alkali metals as follows:

When alkali metals react with water they make alkaline solutions, so the universal indicator turns people and they produce hydrogen and a metal hydroxide. When sodium is put in water, the metal floats on the surface it reacts to form sodium hydroxide and hydrogen.

It is recommended only for the second type of candy to be taken off the market.

Based on the background information, if a candy shows a 0,62 Rf value in the chromatography it is considered potentially dangerous, and therefore it should be taken off the market.

The Rf value is calculated using the following formula:

Now, let's find out if any of the components has an Rf equal to 0,62.

Note: To determine the distances I measured the image using a ruler and you can do the same, this will not alter the results.

     2. Sample 2

This means sample 2 has the 0.62 Rf value and therefore it needs to be taken off the market.

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Answer:

Would you consider adding a sodium carbonate solution to a magnesium sulfate .

Explanation:

??

Answer:

Blank #1: Polyatomic

Blank #2: 2 (see explanation)

Blank #3: 1 (see explanation)

Explanation

Both the ammonium ion  and the sulfate ion  contain more than one atom in each ion. The two species are thus polyatomic. The chloride ion , for example, is monoatomic.

Superscripts above formulae of the ions indicate their charge. Each ammonium ion carries a positive one (+1) charge. Each sulfate ion carries a charge of negative two (-2).

Ammonium sulfate is an ionic compound. A sample of this compound contain myriads of ammonium ions and sulfate ions. The ions are packed in three-dimensional lattices. Thus unlike water, ammonium sulfate does not exist as molecules in nature.

Assuming that the second and third blanks refers to a formula unit, rather than a molecule, of ammonium sulfate. The empirical formula of ammonium sulfate gives the minimum whole-number ratio between the two ions in a sample.

Charges shall balance between the two ions. Ammonium ions are of charge +1. Sulfate ions are of charge -2. The sample shall thus contain two ammonium ions for every one sulfate ion.

The empirical formula of ammonium sulfate is therefore .

There are thus two ammonium ions  and one sulfate ion  in each formula unit of ammonium sulfate.

There are two types of chemical compound one is covalent compound and other is ionic compound, covalent compound formed by sharing of electron and ionic compound formed by complete transfer of electron. Therefore,  a molecule of the ammonium sulfate consists of one NH₄⁺ ions and one SO₄²⁻ ions.

Chemical Compound is a combination of molecule, Molecule forms by combination of element and element forms by combination of atoms in fixed proportion.

An ionic compound is a metal and nonmetal combined compound.  Ionic compound are very hard. They have high melting and boiling point because of strong ion bond. The compound of ammonium sulfate consists of two ions. NH₄⁺ and SO₄²⁻ both of which are polyatomic ions. A molecule of the ammonium sulfate consists of one NH₄⁺  ions and one SO₄²⁻ ions.

Therefore,  a molecule of the ammonium sulfate consists of one  NH₄⁺ ions and one SO₄²⁻ ions.

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Answer:

45th answer is pure and properties 42 is periodictable

Explanation:

When a bond is strong, there is a higher bond energy because it takes more energy to break a strong bond. This correlates with bond order and bond length. When the bond order is higher, bond length is shorter, and the shorter the bond length the greater the bond energy.

Answer: B. no

Explanation:

Answer:They can be spread through skin contact, bodily fluids, airborne particles, contact with feces, and touching a surface touched by an infected person.

Immunise against infectious diseases.

Wash and dry your hands regularly and well.

Stay at home if you are sick.

Cover coughs and sneezes.

Clean surfaces regularly.

Ventilate your home.

Prepare food safely.

Practise safe sex.

Explanation:

The elements fluorine (F), chlorine (CL),and Iodine are all parts of the same _group___ on the periodic table

Answer:

Silicon Dioxide is a compound usually referred to as Quartz, it's a crystalline sort of material that is commonly found and used for equipment and furniture (like tables for example). Their molecular geometry is of tetrahedral shape (how their bonds look like and such)

Gold is an element that is a transitional metal that is quite malleable (able to hammer it to sheets) and is ductile (can be made into wires). As you probably have guessed, gold is used a lot for jewelry due to its lustrous appearance, and the fact that it can't corrode as well as its rarity. Due to it not being able to corrode, it's pretty useful in circuitry as it requires less management unlike elements with higher electrical conductivity like copper or silver. However gold is pretty costly so it's not often relied on for technology and mostly just used for show instead.

N2 or nitrogen gas, may seem like a compound for people new to chemistry but is actually just a diatomic molecule, meaning they are composed of only 2 atoms. So elements that are diatomic are commonly found with only 2 atoms (Oxygen gas for example, or Hydrogen gas) Nitrogen is part of the "magnificent seven" (the elements which are diatomic".  Nitrogen is essential for a lot of living things (aside from us), and since they are the most abundant material in our air (78% of air is Nitrogen), there's plenty of life growing.

Compound and elements are differ from each other. Silicon dioxide ( SiO₂ ) is compound , gold ( Au ) is  element and nitrogen gas ( N₂ ) is compound.

Elements are always made-up of only one type of atom. Molecule is made up of more than one type of atom. Silicon dioxide is a compound, which is crystalline in nature. Their molecular geometry is of tetrahedral shape.

Gold is an element that is a transitional metal that is quite malleable and is ductile.  Gold ( Au ) is used a lot for jewelry. Nitrogen gas is  compound . It is diatomic in nature, So elements that are diatomic are commonly found with only 2 atoms.

Hence, silicon dioxide is compound, gold is element, and nitrogen gas is also compound.

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Answer: all mass takes up space. everything has mass. Theres a unit of mass called a slug thats not the bug!

Explanation:

Answer:

1. Dissolving powder in milk - Chemical

  - It is chemical because the milk has changed on a molecular level

2. Toasting bread - Chemical

   - It is chemical because adding heat to the bread cooks it, therefore

     changing it on a molecular level

3. Melting cheese - Physical

   - It is physical because the physical appearance was the only change

4. Slicing apples or bannanas - Physical

   - It is physical because the physical appearance was the only change

5. Frying an egg - Chemical

   - It is chemical because new particles were formed

6. Milk souring - Chemical

   -  It is chemical because it is forming a new product (lactic acid)

Explanation:

Physical Change occurs when the particles of a substance become rearranged, but do not change into different particles.  

Chemical change occurs when a new substance is formed. This process is irreversable.

Answer:

give the preson above brainly bc there right

Explanation:

Not every earthquake has a(n) Foreshock, but every earthquake has an Aftershock that occurs in the Same place as the mainshock.

An earthquake is defined as a natural disaster in which there are tectonic plates that are present on the earth's crust collides with each other.

An Earthquake can be minor as well as natural depending upon the frequency it causes the damage. Earthquake is the Shaking of Earth and was much destruction of the economy and manpower.

Surroundings are being disturbed like trees will fall, and buildings will collapse which will cause damage to the economy as well as to human life.

Foreshock is the before shop which happens before the earthquake and aftershock is the other socks that happen after the earthquake

Thus, the correct options are 1. Foreshock, 2. Aftershock, 3. The Same place as.

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Considering the reaction stoichiometry, 0.00495 grams of water is produced when  2.75×10⁻⁴ moles of NaOH reacts completely.

Sodium hydroxide (NaOH) and hydrochloric acid (HCl) react to form sodium chloride (NaCl) and water. So, the balanced reaction is:

NaOH + HCl → NaCl + H₂O

By reaction stoichiometry (that is, the relationship between the amount of reagents and products in a chemical reaction), the following amounts of moles of each compound participate in the reaction:

In the periodic table, you can find the molar mass of the elements, also called atomic mass or atomic weight. So, to calculate the molar mass of a compound, you must add the molar mass of the elements of the compound multiplied by the times they appear in the compound.

So, in the case of water:

H₂O= 2× 1 g/mole + 16 g/mole

H₂O= 18 g/mole

Then, if by stoichiometry of the reaction 1 mole of water is produced, the mass of water produced is calculated as:

mass H₂O= 1 mole× 18 g/mole

mass H₂O= 18 g

Then you can apply the following rule of three: if by stoichiometry 1 moles of NaOH produce 18 grams of H₂O, 2.75×10⁻⁴ moles of NaOH will produce how much mass of H₂O?

[tex]mass of H_{2} O=\frac{2.75x10^{-4} moles of NaOHx18 grams of H_{2} O}{1 mole of NaOH}[/tex]

mass of H₂O= 0.00495 grams

In summary, 0.00495 grams of water is produced when  2.75×10⁻⁴ moles of NaOH reacts completely.

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Answer:

Electrons are stored in different electron shells with the nucleus in the center. Depending on the size of the element, the electrons may need more shells, making the electrons further away from the nucleus.

Explanation:

Atoms contains nucleus in its center and electron that revolve around the atom in fixed orbit.  the statement "electrons are always located close to the nucleus of an atom" is not really accurate.

Atom is the smallest particle of any element, molecule or compound. Atom can not be further divided.

In the nucleus, proton and neutron are present. Electron has -1 charge while proton has +1 charge.

Electrons always move in fixed orbit around the nucleus with a particular force. Electrons may or may not be close to the nucleus. Depending on the size of the element, the electrons may need more shells, making the electrons further away from the nucleus.

Therefore,  the statement "electrons are always located close to the nucleus of an atom" is not really accurate.

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Answer:

cell

Explanation:

Cells are the most simple, basic units of life

Answer:

the CELL is the basic unit of life.

Explanation:

I had this is my science lesson

have a great day!

hope this helps!

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Answer:

0.09375 M

Explanation:

You want to use the following equation:

M1*V1=M2*V2

Then plug in the 50ml to V1 and 0.15M to M1 and 80ml to V2 (add the 50 and 30). The next thing you want to do is change the mL to liters, since Molarity is moles/liter. Once that is done, solve algebraically for answer.

** Also don't forget to capitalize the M when you mean Molarity, because it is different than m.**

Hope this helps!

The IUPAC name for a binary covalent compound will lack roman numerals.

Binary covalent compound comprises of two elements which forms a

compound through the sharing of electrons.

The sharing of electrons is referred to as covalent bonding and naming such

compounds require prefixes such as mono-, di- , tri- etc.

The standard method of naming these compounds should be with the

prefixes and not with the roman numerals.

An example is carbon(IV)oxide which is wrong in  IUPAC naming.

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Answer:

B

Explanation:

Just did the test on edge 2021