If you know about crystals can you tell me if this is real or fake because I purchased this item and don’t know

Answer:

B) CaO(s) + H2O(l) --> Ca(OH)2(aq)

Explanation:

This is the only reaction with a negative enthalpy value. Exothermic reactions have a negative enthalpy.

Explanation:

acid ,HNO3

base,KOH

salt ,KNO3

Answer:

Some of these parts, called organelles, are specialized structures that perform certain tasks within the cell. ... It also provides a track-like system that directs the movement of organelles and other substances within cells. Endoplasmic reticulum (ER) This organelle helps process molecules created by the cell

Organelles perform specific tasks within the cells such as protein synthesis, energy production, etc.

Organelles are specialized structures that perform different functions in the cells. Examples of organelles include lysosome, nucleus, chloroplast, mitochondria, endoplasmic reticulum, etc.

It should be noted that every cell process is done in a particular location in the cell. Some of the functions that are performed by the organelle include processing of food and waste, protein synthesis, energy production, replication, etc.

For example, the nucleus is used for the storage of DNA, mitochondria is vital for energy production, the ribosome is necessary for protein synthesis, etc.

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Answer:

Selenium Dioxide: Se[tex]O_{2}[/tex]

Explanation:

This is a compound that contains both Selenium and Oxygen.

Answer:

44.2 L

Explanation:

Use Charles Law:

[tex]\frac{V1}{T1} =\frac{V2}{T2}[/tex]

We have all the values except for V₂; this is what we're solving for. Input the values:

[tex]\frac{56 L}{346K} =\frac{V2}{273K}[/tex]   -  make sure that your temperature is in Kelvin

From here, we need to get V₂ by itself. To do this, multiply by 273 on both sides:

[tex]\frac{56*273}{346} = V2[/tex]

Therefore, V₂ = 44.2 L

It's also helpful to know that temperature and volume are linearly related. So, when temperature drops, so will volume and vice versa.

Answer:

nah you good

Explanation:

it's perfect don't doubt yourself

Answer:

[tex]\boxed {\boxed {\sf N_2}}[/tex]

Explanation:

Let's examine this reaction, especially the coefficients.

[tex]N_2+3H_2 \rightarrow 2NH_3[/tex]

First of all, remember that reactants are used to make the product. They are found on the left of the arrow usually. Therefore, N₂ and H₂ are the reactants, while NH₃ is the product. We can automatically eliminate NH₃ from our answer choices, because it is simply not a reactant.

Next, look at the coefficients.

Therefore, for the reaction to work, there must be 1 mole of N₂ and 3 moles of H₂.

We have 3.2 moles of N₂ and 5.4 moles of H₂.

Divide each amount given by the required amount for completion.

Therefore, there is enough nitrogen to complete the reaction 3.2 times, but only enough hydrogen for 1.8 times. If everything is completely reacted, we will run out of hydrogen and have excess nitrogen.

Matter cannot be created or destroyed in chemical reactions. This is the law of conservation of mass. In every chemical reaction, the same mass of matter must end up in the products as started in the reactants. Balanced chemical equations show that mass is conserved in chemical reactions.

Matter cannot be created or destroyed in chemical reactions. This is the law of conservation of mass. In every chemical reaction, the same mass of matter must end up in the products as started in the reactants. Balanced chemical equations show that mass is conserved in chemical reactions

Answer:

Explanation:When silver Ag metal is added to copper sulphate CuSO4 solution, no reaction takes place as silver is less reactive than that of copper and cannot displace copper from its solution. Hence, when a piece of silver metal is added to copper sulphate solution there will be no reaction.

Answer:

There will be no reaction

Explanation:

Therefore, when silver Ag metal is added to copper sulphate CuSO4 solution, no reaction takes place as silver is less reactive than that of copper and cannot displace copper from its solution. Hence, when a piece of silver metal is added to copper sulphate solution there will be no reaction.

Answer:

False

Explanation:

Ionic bonds are actually strong, but unfortunately can be broken easily

Answer:

3.64M is the molar concentration of the solution

Explanation:

Molarity (Molar concentration, M) is an unit of concentration widely used in chemistry defined as the ratio between the moles of solute (In this case, KCl) and the volume of the solution in liters.

As you can see, the moles of KCl are 2.21 mol, and the volume of the solution is 0.6068L. The molarity is:

2.21mol / 0.6068L =

Answer:

a. pH = 2 b. pH = 3 c. pH = 1 d. Unanswerable

Explanation:

pH = -log[H+] OR pH = -log{H3O+]

                    and inversely

pOH = -log[OH-]

1. Determine what substance you are working with, (acid/base)

2. Determine whether or not that acid or base is strong or weak.

a. 1.0 x 10^-2M HCl

HCl is a strong acid, therefore it will dissociate completely into H+ and Cl- with all ions going to the H+, therefore, the concentration of HCl and concentration of H+ are going to be equal, meaning we simply take the negative logarithm of the concentration of HCl and that would equal pH

pH = -log[H+]

pH = -log(1.0x10^-2)

pH = 2

b. 1.0 x 10^-3M HNO3

HNO3 like part a, is a strong acid, therefore it would simply require you to take the negative logarithm of the concentration of the compound itself, to find its pH.

pH = -log[H+]

pH = -log(1.0 x 10^-3)

pH = 3

c. 1.0 x 10^-1M HI

Like the previous parts, HI is a strong acid

pH = -log[H+]

pH = -log(0.10)

pH = 1

d. HB isn't an element, nor is it a compound so that would be unanswerable.

In a dry cell the electrolyte is a paste.

Minerals with an electric charge called electrolytes could be found in human blood and other bodily fluids. Electrolytes have a variety of effects on how your brains work, including how much water is in your body. The pH balance in the blood (pH) Our muscles work.

The dry-cell battery would be a gadget composed of one or even more electrochemical cells which change electrical energy from chemical energy that has been stored. It has an electrolyte inside of a paste or another moist substance. Zinc anode, as well as carbon cathode, are found inside a central rod of a standard dry cell battery.

Therefore, in a dry cell the electrolyte is a paste.

Hence, the correct answer will be option (B).

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#SPJ1

. Consider a sample of oxygen gas at 27° C with a volume of 9.55L at a pressure

Answer:620 k

Explanation:

Answer:

237.80mL

Explanation:

Molarity of a solution can be calculated using the formula;

Molarity = number of moles (n) ÷ volume (V)

However, we first need to calculate the number of moles of Cu(NO3)2 by using the formula:

moles = mass/molar mass

Molar mass of Cu(NO3)2 = 187.56 g/mol

moles = 146.59 ÷ 187.56

moles = 0.782moles

Molarity = n/V

3.28 = 0.78/V

V = 0.78/3.28

V = 0.2378L

In milliliters (mL), 0.24 litres = 0.24 × 1000

= 237.80mL

Answer:

Q = 2997.69 J

Explanation:

Given that,

The mass of ice, m = 15.6 grams

The temperature increases from -8.76 degrees Celsius to 85.9 degrees Celsius.

The specifc heat of ice is 2.03 J/g°C

We need to find the amount of energy required. The formula for energy required is given by :

[tex]Q=mc\Delta T\\\\=15.6\times 2.03\times (85.9-(-8.76))\\\\=2997.69\ J[/tex]

So, the required heat is equal to 2997.69 J.

Answer:

Acid is a kind of chemical compound that when dissolved in water gives a solution with H+ ion activity more than purified water. A base is an aqueous substance that donates electrons, accept protons or release hydroxide (OH-) ions. An acid is a proton donor. While a base is a proton acceptor.

Explanation:

Hey mate, here's your answer...

Answer:

Rocks get older as we go away from the Mid Atlantic Ridge  towards the continents

Explanation:

As the plates move away from each other, new ocean lithosphere is created at the ridge. This also widens the ocean basin and leads to sea floor spreading.

The rock of the ocean floor are symmetrically aligned and they get become older as they move away from the crest of the ridge.

Thus, rocks get older as we go away from the Mid Atlantic Ridge  towards the continents

Answer:

This is an example of a physical change because the ice cubes began to melt.

This is an example of a physical change because the ice cubes began to melt.

Explanation:

The above is the right answer to the question about the dissolution of the whole mixture mentioned in the excerpts above.

Answer: [tex]Fe^{3+} > Mn^{4+}[/tex] > [tex]V^{3+}[/tex] = [tex]Ni^{2+}[/tex] > [tex]Cu^+[/tex]

Explanation:

Electronic configuration represents the total number of electrons that a neutral element contains. We add all the superscripts to know the number of electrons in an atom.

Fe: 26: [tex]1s^2s^22p^63s^23p^64s^23d^{6}[/tex]

[tex]Fe^{3+}:23:1s^2s^22p^63s^23p^63d^{5}[/tex] : 5 unpaired electrons

Mn: 25: [tex]1s^2s^22p^63s^23p^64s^23d^{5}[/tex]

[tex]Mn^{4+}:23:1s^2s^22p^63s^23p^63d^{3}[/tex] : 3 unpaired electrons

V: 23: [tex]1s^2s^22p^63s^23p^64s^23d^{3}[/tex]

[tex]V^{3+}:23:1s^2s^22p^63s^23p^63d^{2}[/tex] : 2 unpaired electrons

Ni : 28 : [tex]1s^2s^22p^63s^23p^64s^23d^{8}[/tex]

[tex]Ni^{2+}:23:1s^2s^22p^63s^23p^63d^{8}[/tex]: 2 unpiared electrons

Cu : 29 : [tex]1s^2s^22p^63s^23p^64s^13d^{10}[/tex]

[tex]Cu^{+}:23:1s^2s^22p^63s^23p^63d^{10}[/tex]: 0 unpaired electrons

Thus the order of decreasing number of unpaired electrons:

[tex]Fe^{3+} > Mn^{4+}[/tex] > [tex]V^{3+}[/tex] = [tex]Ni^{2+}[/tex] > [tex]Cu^+[/tex]

Answer:

Formula and structure: The chemical formula of calcium chloride is CaCl2, and its molar mass is 110.983 g/mol. It is an ionic compound consisting of the calcium cation (Ca2+) and two chlorine anions (Cl-). The bivalent calcium metal forms an ionic bond with two chlorine atoms, as shown below.

Based on the ionic nature of calcium chloride,  the chemical symbols of the particles found in the calcium chloride crystal is Ca²⁺ and Cl⁻.

Ionic compounds are compounds which are composed of ions.

Calcium chloride is an ionic compound composed of the ions, calcium ions and chloride ions.

The chemical formula of calcium chloride is CaCl2, and its molar mass is 110.983 g/mol.

The symbol for  calcium ion is Ca²⁺

The symbol for chloride ion is Cl⁻.

Therefore, the chemical symbols of the particles found in the calcium chloride crystal is Ca²⁺ and Cl⁻.

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Answer:

Florida

Explanation:

Directly north of Cuba is the rural bar fight of a state, Florida

Answer:

The Answers are B, C, and E.

Explanation:

Fossils of nearly identical species are found on both South America and African continents. Marsupials existed on both North American and Australian continents when these land masses were connected. Areas of subduction often have high seismic activity as one plate moves under another plate. Since the continents were once joined, there is the likelihood that species originated in one location and then spread to other areas as the continents moved is likely. This explains the similarity of fossils or species in very geographically remote areas. The high activity of seismic movement also is best explained by plate movement.

The  statements that supports the theory of plate tectonics are:

According to the question, we are asked to prove the evidence of the plate tectonic theory based on the movement of continental plates across the Earth's surface.

Plate tectonic theory states that there is a detachment of the outer crust of the Earth and they join when the upper part meets the continental plates and diverges across the planet.

Therefore, the statements that support this theory are the facts that:

Therefore, the correct answers are options B, C and E

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Answer:

See explanation

Explanation:

The valence shell electron pair repulsion theory holds that the number of electron pairs on the outermost shell of the central atom in a molecule determines the shape of the molecule.

In accordance with this theory, the electron domain geometry of a molecule having 4 outer atoms and 2 lone pairs on the central atom is based on an octahedron. The molecular geometry of this molecule is square planar with a bond angle of 90 degrees.