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chemistry redox

density of the pumice.

density= mass/ volume (d= m/v)

= 225/236.6

= 0.951g/ml

so, the density of pumice is 0.951g/ml.

[tex]{\boxed{{ formula :}}} [/tex]

[tex] →\bold{Density = \frac{mass}{volume} }[/tex]

[tex]{\boxed{{ Given :}}} [/tex]

[tex]→\bold{Mass = 225 g }[/tex]

[tex]→\bold{ Volume = 236.6 ml}[/tex]

[tex]{\boxed{{ Solution :}}} [/tex]

[tex]→\bold{Density = \frac{mass}{volume} }[/tex]

[tex]→\bold{ Density = \cancel{ \frac{225 g}{236.6 ml}} = 0.951 g/ml}[/tex]

The density of pumice is 0.951 g/ ml .

Answer:

you have school on Sunday?

Answer:

it will fall then rise and return to ×

ppm = mg/l = mg/kg

32 mg / 20 kg = 1.6 ppm

The concentration in ppm of sodium fluoride in tap water is 1.6 ppm.

ppm is  an abbreviation for parts per million. It can also be expressed as  milligrams per liter of a solution.It is a measurement which is equal to mass of a substance per unit volume .

One ppm is equivalent to the absolute fractional amount which is multiplied  by a million . It is a best way to describe smaller concentrations in a mixture such as that of gases,liquids or solids . It is a ratio of two quantities   which have  the same unit. In its full form ppm is expressed as one in a million part.

Depending on the substance being measured 1 ppm is expressed in many different ways, out of which preferred ways are microliters per liter , milligrams per liter and micrograms per liter.

For the given problem, concentration in ppm is found out as, since ppm is miiligrams  per liter the concentration is found out as follows:32 mg/20 kg (since kilograms  and liters  are  equivalent) =1.6 ppm

Thus, the  final concentration of sodium fluoride in tap water  which is fluorinated is 1.6 ppm.

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Answer:

why is most space exploration accomplished with spacecraft that do not have crews on board? humans face many challenges in space. what is one advantage of using an orbiter to study objects in space? can be used for long periods of time.

Based on the research in Study 1, as the wavelength of light increases, the reflectance of Cyanide: C. increases, then decreases.

Wavelength is simply defined as the distance (in meters) between two (2) successive crests or troughs of a wave. Thus, wavelength refers to the horizontal distance between two adjacent crests or troughs of a wave.

Generally, there is a linear relationship between the wavelength of light and reflectance. Thus, as the wavelength of light increases, the reflectance of Cyanide in Study 1 increases, before it then decreases.

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Tautomers are isomers composed of the same atoms but with different electronic and molecular structures. The most stable tautomeric form is attached.

Tautomery is a special case of isomery produced by the change in the position of one or more atoms in the molecule. This change in position modifies the molecular electronic distribution, and hence, the molecular structure.

In solution, isomeres called tautomers are in equilibrium, and the constant interconversion is called tautomerization. Both molecules have the same type and quantity of atoms.

In the proposed example, the product has the molecular formula C₁₀H₁₆O₃. Isomeric molecules must have 6C, 16H, and 3O. However, the distribution of these atoms varies, leading to a change in the product molecule structure.

In the attached files you will find an example. You should check if this is the same example as yours.  

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Chemical weathering formed is due to acids formation when atmospheric and volcanic gases mix with water.

Chemical weathering is a type of weathering that involved weakening and disintegration of rock by chemical reactions like acid reactions and so on. These reactions include oxidation, hydrolysis, and carbonation. These processes lead to formatiom or destruction of minerals, thus changing the nature of the rock's mineral composition.

Therefore, Chemical weathering is due to acids formed when atmospheric and volcanic gases mix with water.

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If a gas in a balloon occupies 2.25 L at 298 K and 300 kPa, the temperature at which the balloon expand to 3.50L and 2.17 atm is 345.23K.

The temperature of an ideal gas can be calculated using the following formula:

P1V1/T1 = P2V2/T2

Where;

According to the information given in this question;

2.96 × 2.25/298 = 2.17 × 3.5/T2

0.022T2 = 7.595

T2 = 7.595 ÷ 0.022

T2 = 345.23K

Therefore, if a gas in a balloon occupies 2.25 L at 298 K and 300 kPa. the temperature at which the balloon expand to 3.50L and 2.17 atm is 345.23K.

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Answer:

Cassiterite is an ore of Sn.It is also called tinstone and has molecular formula of SnO

2 . It is heavy, metallic, hard tin dioxide that is the major ore of tin. It is colourless when pure, but brown or black when iron impurities are present.

Answer:

Write the name of high quatity of coal​

Explanation:

Answer:

applied force .....I'm pretty sure

Answer:

A. Applied forces aka Contact forces

Explanation:

Thos force is created when you apply forces to an object as in a push/pull or other physical ways.

I hope it helps! Have a great day!

Anygays-

Answer:

Below

Explanation:

1. Sodium Bromide

2. Potassium Chloride

3. Magnesium Oxide

4. Calcium Fluoride

5. Barium Sulfide

6. Lithium Oxide

7. Sodium Fluoride

8. Cesium Nitride

The leaves of plants primarily serve to photosynthesize and require water conducted by the root to do so.

As a leaf of a plant running low on supplies that the root is responsible for, what I will be needing is water.

Thus, I will have to send a text message to the root to supply me with water. The root will respond by asking its foot soldiers (the root hairs) to conduct water into the root.

Once water gets into the root, it enters special cells that are responsible for conducting water inside plants - the xylems. The root sends the water through the xylem and water travels from there to me - the leaf.

Once the water gets to me, I will use it in combination with inorganic carbon (carbon dioxide) to synthesize carbohydrates.

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Answer:
Acid mine drainage
metal contamination,
increased sediment levels in streams

Explanation:

ACID MINE DRAINAGE
Mine waste, heavy metals and acidic water often end up in streams and rivers.

METAL CONTAMINATION
Heavy metals also affect the biodegradability of organic pollutants, making them less degradable and thus causing double the effect of polluting the environment.

Answer: salt and petroleum

Explanation:

Just took this today and im pretty sure this is the right one

Answer:

Fluorine needs two more electrons on the outermost shell.

Explanation:

I'm in K12 too.

Answer:

a 63.428gm

b 41.5 gm

Explanation:

a

70 gm CaCOH2=111gm of CaCl2

40 gm =(111*40)/70

=63.428gm

b

107 gm of NH4Cl =111 gm of CaCl2

40 gm gives =(111*40)/107

=41.5 gm

The pressure of the sample of gas with the given mol, volume and temperature is 5.33atm.

The Ideal gas law or general gas equation emphasizes on the state or behavior of a hypothetical ideal gas. It states that "pressure P times volume V is equal to moles times temperature and the universal gas constant. It is expressed;

PV = nRT

Where P is pressure, V is volume, n is the amount of substance, T is temperature and R is the ideal gas constant ( 0.08206 Latm/molK ).

Given the data in the question;

We substitute our values into the expression above to determine the pressure of the gas in atmospheres.

PV = nRT

P = nRT / V

P = ( 6mol × 0.08206Latm/molK × 238K ) / 22L

P = 117.18168Latm / 22L

P = 5.33atm

Therefore, the pressure of the sample of gas with the given mol, volume and temperature is 5.33atm.

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Explanation:

I hope this helps answer your questions

Based on the nature ofbthe reaction, entropy (ΔS) increases while enthalpy (ΔH) decreases.

Entropy changes, ΔS, refers to change in the degree of the disorderliness of a substance.

When substances become more random, entropy increases and vice versa.

For example, change of state from solid to liquid or gas results in increase in entropy.

Enthalpy changes, ΔH, refers to the changes in heat content of a substance, either a decrease or increase.

Enthalpy is negative when heat is lost and positive ehen heat is gained.

The enthalpy and entropy changes in the given reaction below is as follows:

2CaO(s) + H2O(l) —> 2Ca(OH)2(s)

Entropy, ΔS increases as the substance dissolves in water.

Enthalpy, ΔH, decreases as the substances gives off heat.

Therefore, in the given reaction entropy (ΔS) increases while enthalpy (ΔH) decreases.

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Answer:

D) H₂SO4 is an acid

Explanation:

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H[tex]_2[/tex]SO[tex]_4[/tex] is the chemical formula that should be classified as an acid. Therefore, the correct option is option D.

Any substance that tastes acidic when dissolved in water, alters the colour of some indicators, reacts with the some metals to release hydrogen, reacts using bases to produce salts, and stimulates some chemical reactions is considered to be an acid. The inorganic chemicals referred to as being mineral acids sulfuric, nitrous, hydrochloric, or phosphoric acids are examples of acids.

The phenolic, sulfonic, and carboxylic acid groups of organic molecules. These chemicals contain one or maybe more hydrogen atoms, which are discharged into highly charged hydrogen ions when they are in solution. H[tex]_2[/tex]SO[tex]_4[/tex] is the chemical formula that should be classified as an acid.

Therefore, the correct option is option D.

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Answer:

i think this is right!

Explanation:

An example of a single replacement reaction occurs when potassium (K) reacts with water (H2O). A colorless solid compound named potassium hydroxide (KOH) forms, and hydrogen gas (H2) is set free. The equation for the reaction is: 2K + 2H2O → 2KOH + H.

An example of a double replacement reaction is the reaction between silver nitrate and sodium chloride in water. Both silver nitrate and sodium chloride are ionic compounds. Both reactants dissolve into their ions in aqueous solution.

Answer:

The answer is that the pathogen has become an established part of the host's resident microbiota. :)

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Answer:

Cr2(SO4)3+K2CO3---------------->Cr2(CO3)3+K2SO4

BALANCING

Cr2(SO4)3+3K2CO3------------------------->Cr2(CO3)+3K2SO4

Explanation:

Answer:

None of the above.

Explanation:

None of thesse things are part of the structure of a cow, cows have dished forhead 4 stomachs and angular body not sharp teeth comin when called or hooved feet.

Answer:

It has no definite shape or volume.