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Answer:

a. 53.5 g/mol

b. 80.06 g/mol

c. 133.33 g/mol

General Formulas and Concepts:

Chemistry - Atomic Structure

Explanation:

Step 1: Define

a. NH₄Cl

b. NH₄NO₃

c. AlCl₃

Step 2: Find masses

Molar Mass of N - 14.01 g/mol

Molar Mass of H - 1.01 g/mol

Molar Mass of O - 16.00 g/mol

Molar Mass of Al - 26.98 g/mol

Molar Mass of Cl - 35.45 g/mol

Step 3: Calculate compound masses

Molar Mass of NH₄Cl - 14.01 g/mol + 4(1.01 g/mol) + 35.45 g/mol = 53.5 g/mol

Molar Mass of NH₄NO₃ - 2(14.01 g/mol) + 4(1.01 g/mol) + 3(16.00 g/mol) = 80.06 g/mol

Molar Mass of AlCl₃ - 26.98 g/mol + 3(35.45 g/mol) = 133.33 g/mol

Answer:

pH = 2.75

Explanation:

Methanoic acid, HCOOH, is in acidic equilibrium:

HCOOH ⇄ HCOO⁻ + H⁺

And Ka is defined as:

Ka = 1.6x10⁻⁴ = [HCOO⁻] [H⁺] / [HCOOH]

As both HCOO⁻ and H⁺ ions comes from the same equilibrium, we can solve these concentrations assuming the HCOOH produce X of both HCOO⁻ and H⁺ ions:

1.6x10⁻⁴ = [HCOO⁻] [H⁺] / [HCOOH]

1.6x10⁻⁴ = [X] [X] / [0.02M]

3.2x10⁻⁶ = X²

X = 1.79x10⁻³M = [H⁺]

As pH = -log [H⁺]

The pH of the 0.02 M methanoic acid is 2.75 acid when the dissociation constant is [tex]1.6 \times 10^{-4} \rm \ M.[/tex]

At equilibrium, the dissociation of Methanoic acid,  

HCOOH ⇄ HCOO⁻ + H⁺

In the reaction, Methanoic acid dissociates to form HCOO⁻ and H⁺. So, the concentration of both products will be equal.

pH can be calculated by using Ka,

[tex]\bold{Ka = \dfrac {[HCOO^-] [H^+] }{[HCOOH]}}[/tex]

Where,

Ka - dissociation constant = 1.6x10⁻⁴

[HCOOH ] - concentration of Methanoic acid = 0.02 M

[tex]\bold{1.6 \times 10^{-4} M.= \dfrac {[HCOO^-] [H^+] }{[HCOOH]}}[/tex]

Let the concentration of each product is [tex]x[/tex]

So,

[tex]\bold{1.6 \times 10^{-4} \ M}= \dfrac {[x] [x] }{[0.02]}}\\x^2 = 3.2\times 10^{-6}\\x = 1.79\times 10^{-3}\rm \ M[/tex]

Put the value in the pH formula,

[tex]\bold {pH = - log [H^+]}\\\\\bold {pH =- log \ 1.79\times 10^{-3}\rm \ M}\\\\\bold {pH = 2.75 }[/tex]

Therefore, The pH of the 0.02 M methanoic acid is 2.75 acid when the dissociation constant is [tex]1.6 \times 10^{-4} \rm \ M.[/tex]

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Answer:

B: Maintaining Homostasis

Explanation:

Answer:

675 K

Explanation:

[tex]\dfrac{P_1V_1}{T_1}=0.03\ \text{atm L/K}[/tex]

Presión del sistema 2 = [tex]P_2=4.5\ \text{atm}[/tex]

Volumen del sistema 2 = [tex]V_2=4500\ \text{mL}=4.5\ \text{L}[/tex]

De la ley de los gases ideales tenemos la relación

[tex]\dfrac{P_1V_1}{T_1}=\dfrac{P_2V_2}{T_2}\\\Rightarrow 0.03=\dfrac{4.5\times 4.5}{T_2}\\\Rightarrow T_2=\dfrac{4.5\times 4.5}{0.03}\\\Rightarrow T_2=675\ \text{K}[/tex]

La temperatura del sistema para el segundo sistema es 675 K.

Answer:

Explanation:

A

Answer:

calcium cation

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-).

Explanation:

Answer:a and d

Explanation:

The properties of ionic compounds are hard solids with high melting and boiling points and good conductors of electricity, but only when dissolved in water and the correct options are option A and D.

Ionic solids are made up of ions joined together by ionic bonds. "Ionic bonding" is a type of chemical bond between a positive and a negatively charged ion where the transfer of electrons occurs.

They are too hard, and the ionic solids’ melting point is usually too high due to powerful forces between the anions and cations.

They are known as electrical insulators when they are in a solid-state. Apart from this, the molten salts do behave with electricity since the ions are not closed in the lattice.

Therefore, the properties of ionic compounds are hard solids with high melting and boiling points and good conductors of electricity, but only when dissolved in water and the correct options are option A and D.

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Answer:

2 ;)

Explanation:

Explanation:

A = Golgi body

B = Vacuole

C = Mitochondrion

D = Nucleus

E = Cell membrane

Answer:

A = Golgi body

B = Vacuole

C = Mitochondrion

D = Nucleus

E = Cell membrane

Explanation:

give credit to the other person they helped me

too have a good day :)

Answer:

C₃H₆ + H₂O = C₃H₈O

Explanation:

Hydration reactions (reactions involving converting an alkene to alcohol) have only one product, so there will be no byproduct along with propanol.

Propene reacts with steam to produce propan-2-ol. The reaction is C₃H₆ +H₂O[tex]\rightarrow[/tex]C₃H₈O. It is an example of hydration reaction.

Hydration reaction is defined as a chemical reaction wherein a substance combines with water. In organic chemistry, when an unsaturated substance reacts with water it is called as hydration reactions.

The reaction involves breaking of hydroxyl bond in water which is highly  exothermic releasing large amount of energy. Direct addition of water to an alkene is too slow and hence the rate is catalyzed by Lewis acids or Bronsted acids.

Hydration reactions are extensively used   for industrial production of butanol and isopropanol,etc.The addition of water along the double bond in alkenes takes place according to Markovnikov's rule.

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It is 2 KJ

It is because the formula is :

q=m∆Hf

where m is the mass and ∆Hf is the heat fusion.

So, we get:

q=80×25

q=2000J or 2 KJ

Answer:

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Explanation:

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Answer:

A is  Mg^2+

B is K^+

C is Se^2-

D is Cl^-

Ca^2+ lies between  Mg^2+ and K^+

S^2-  lies between K^+ and Se^2-

Explanation:

I have attached an image of the four spheres.

Remember that, cations are smaller in size than the corresponding atom atom because the formation of a cation often involves the removal of an entire shell. Anions are larger in size than the corresponding atom because an electron is added thereby expanding the electron cloud and size of the anion.

From left to right let us designate the spheres as ABCD.

A is  Mg^2+

B is K^+

C is Se^2-

D is Cl^-

Ca^2+ lies between  Mg^2+ and K^+

S^2-  lies between K^+ and Se^2-

The size of the spheres, going from smallest to largest, would be: [tex]Mg^2^+[/tex], [tex]K^+[/tex], [tex]Ca^2^+[/tex], [tex]Cl^-[/tex], [tex]S^2^-[/tex], [tex]Se^2^+[/tex].

We can arrive at this answer because:

This is because when donating electrons, the cations get the largest number of protons. This makes the cation nucleus attract the electronic layers, decreasing their extension. In anion, the opposite happens and the increase of electrons increases the extension of the electronic layers.

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Answer:

b-acting as a standard unit of measure

Explanation:

Julie uses the mark for initially acting as a standard unit of measure. The correct option is b.

Recognizing and writing down an occurrence or fact is the process of observation, which frequently entails measuring it with tools. Utilizing tools for measurement is frequently required when recognizing and documenting an occurrence or fact. Written observations taken during or right after fieldwork are referred to as field notes.

They are essential for comprehending occurrences observed in the field. Scratch notes, diaries, and notebooks are common formats for field notes. The process of observation is essential in science. Snails are the molluscan. It comes under zoological study.

Therefore, the correct option is b. acting as a standard unit of measure

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Answer:

eek um A.The substance(s) to the left of the arrow in a chemical equation are called reactants.  The substance(s) to the right of the arrow is called products.

Explanation:

Answer: a solution where the solvent is water

Explanation: solute ions which are known as the dissolvable ions and molecules are surrounded by water molecules and then get incorporated into the bonding network of water

Answer:

Al + 3NaOH  = Al(OH)₃ +3Na

Explanation:

The reaction is given as:

            Al + NaOH  = Al(OH)₃ + Na

This reaction is called a single displacement reaction in which one specie displaces another from a solution.

 To balance the equation:

                aAl + bNaOH  = cAl(OH)₃ + dNa

a, b, c and d are the coefficient that will balance the equation:

     Conserving Al;

                 a = c

     Conserving Na;

                b  = d

     Conserving O;

                 b  = 3c

     Conserving H;

                b = 3c

Let a  = 1, c = 1, b = 3 and d = 3

             Al + 3NaOH  = Al(OH)₃ +3Na

Answer:

That would be a physical change

Explanation:

A physical change is when you are changing the physical properties of something but not changing its overall identity and a chemical change is when yo are changing the physical properties and changing its identity .

Ex. Ripping a dollar bill- Physical change

     Burning a dollar bill- chemical change

Answer:

first one is physical , second one is chemical

Explanation:

Answer:

It's called Independent variable

Explanation:

....

Answer:

25.9 g

Explanation:

Given that,

No of moles of calcium phosphate, [tex]n=9.3\times 10^{-2}[/tex]

We need to find how many grams of calcium phosphate has this much of no of moles.

Mass divided by molar mass is equal to the no of moles on a molecule.

The molar mass of calcium phosphate is 310.18 g/mol

Using the concept of no of moles as follows :

[tex]n=\dfrac{m}{M}\\\\m=n\times M\\\\m=9.3\times 10^{-2}\times 310.18\\\\m=28.84\ g[/tex]

Out of given options, option (a) i.e. 25.9 g is the correct answer.

Answer:

work

matter

potentioal

kinetic

physical

food

Explanation:it is in the order above ^

Answer:

0.0305 moles of MgCO₃

Explanation:

In order to solve this problem, we first need to calculate the molecular weight of MgCO₃:

Finally we divide the mass by the molecular weight, to calculate the number of moles:

Answer:

1. Combine iron and copper (II) sulfate solution.  (Hint: Iron will form the iron (III) ion)

Fe + CuSO4 → FeSO4 + Cu

2. Combine lead (II) nitrate and potassium iodide solutions.

Pb(NO3)2+ Kl →  Pbl2 + 2KNO3

3. Combine magnesium metal and hydrochloric acid solution.

Mg + HCl → MgCl2 + H2

4. Electrolysis (splitting) of water.  

H2O → 2H2 + O2

5. Burning magnesium.

Mg + O2 → Mg2+O2-

Explanation:

Answer:

False

Explanation:

if this were true then water would not be available on earth other than in the atmosphere because of evaporation

Answer:

This one here shows the proper use of parentheses>>>Ca(NO3)2

Answer:

16- physical

14- chemical

15- chemical

13- physical

Explanation:

A chemical change would be something like the burning of wood, it's an object changing into something new, or something changing. A physical change would just basically altering something like bending wood, it's still wood whether or not you bend it.

Answer:Crystalline solids have well-defined edges and faces, diffract x-rays, and tend to have sharp melting points. In contrast, amorphous solids have irregular or curved surfaces, do not give well-resolved x-ray diffraction patterns, and melt over a wide range of temperatures.

Explanation:

Answer:

:-::-::

Explanation: