help!!!! the relative formula mass (Mr) of sodium fluoride is 42. Use the correct answer frim the box to complete the sentence.​

This question is describing two chemical equations whereby the concentration of ammonia has to be determined. The first reaction is between 25.00 mL of ammonia and 50.00 mL of 0.100-M HCl whose excess was neutralized with 21.50 mL of 0.050-M Na₂CO₃ and thus, the concentration ammonia in the cloudy solution was determined as 0.114 M.

First of all we need to go over the titration of the excess HCl with Na₂CO₃ by writing the chemical equation it takes place when they react:

[tex]2HCl+Na_2CO_3\rightarrow 2NaCl+CO_2+H_2O[/tex]

Whereas the mole ratio of HCl to Na₂CO₃ is 2:1 and the volume of the HCl leftover is determined as follows:

[tex]V_{HCl}^{leftover}=\frac{2*0.050M*21.50mL}{0.100M} =21.5mL[/tex]

Next, we infer that the consumed volume of HCl by the ammonia solution was:

[tex]V_{HCl}^{consumed}=50.00mL-21.50mL=28.5 mL[/tex]

Then, we write the chemical equation that takes place between ammonia and HCl:

[tex]HCl+NH_3\rightarrow NH_4Cl[/tex]

Whereas the mole ratio is now 1:1, which means that the concentration of ammonia was:

[tex]M_{NH_3}=\frac{28.5mL*0.100M}{25.00mL}\\\\ M_{NH_3}=0.114M[/tex]

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Answer:

The egg will gain mass.

Explanation:

Eggs soaked in distilled water will gain mass and appear dramatically swollen.

Answer:

Gain mass

Explanation:

Carbonated water will create a reaction inside the egg making the fluid inside the egg becoming more solid thus gaining mass

Hope this helps!

the second options

the number of protons and electrons found in that element

Answer:

Liquid sugar is the sugar you consume in liquid form from beverages like sugar sweetened soda. The sugar in beverages is often highly concentrated and easy to consume in large amounts without feeling full. Some examples of these drinks are fairly obvious, such as sodas and fruit punch.

Answer:

The soda or the egg?

Explanation:

The soda will gain but the egg will lose it may take a while though

Answer:

Gains Weight UwU

Explanation:

Given that –

We know that –

Then –

[tex]\qquad[/tex][tex]\bf\longrightarrow pOH = 14 -12.5 [/tex]

[tex]\qquad[/tex][tex]\sf \longrightarrow pOH = 1.5[/tex]

[tex]\qquad[/tex][tex]\sf \longrightarrow [OH^- ] = 10^{-1.5 }[/tex]

[tex]\qquad[/tex][tex]\bf \longrightarrow [OH^-] = 3.16 × 10^{-2}[/tex]

Now the number of moles of KOH need to ensure that concentration of Hydroxide anions is equal to –

[tex]\qquad[/tex][tex]\bf \longrightarrow 3.74\: L \times \dfrac{3.16× 10^{-2}}{1 \: L }[/tex]

[tex]\qquad[/tex][tex]\bf \longrightarrow 1. 18 × 10^{-1 }M [/tex]

Volume of the solution contains the need number of moles of Hydroxide anions –

[tex]\qquad[/tex][tex]\sf \longrightarrow \dfrac{ 1.18×10^{-1} \: moles \: OH^-}{0.826 \: moles \: OH^-}[/tex]

[tex]\qquad[/tex][tex]\sf \longrightarrow 0.143 L [/tex]

[tex]\qquad[/tex][tex]\sf \longrightarrow 0.143 \times 1000[/tex]

[tex]\qquad[/tex][tex]\pink{\bf\longrightarrow 143 mL }[/tex]

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Answer:

the bond is ionic

Explanation:

Answer:

So, Percentage Composition of Aluminium = 2778×100%=34.62% (approx.) Percentage Composition of Oxygen = 3×1678×100%=61.54% (approx.)

I believe the answer would be D

The London forces designated as A are much weaker than the dipole- dipole interaction designated as B.

The intermolecular forces are interactions that exists between molecules of a substance in a particular state of matter. The nature of intermolecular forces in a substance greatly affect the properties of the substance.

We can see that A represents weak London forces while B represents dipole - dipole interactions. The London forces are very much weaker than the dipole - dipole interactions.

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Answer:

When we do multiple trials of the same experiment, we can make sure that our results are consistent and not altered by random events and are reliable. Multiple trials can be done at one time. E.g. If we were testing a new fertilizer, we could test it on lots of individual plants at the same time.

Hope that helped.x

The mass of ammonium chloride that must be added is : ( A ) 4.7 g

Given data :

Volume of water ( V )  = 250 mL = 0.25 L

pH of solution = 4.85

Kb = 1.8 * 10⁻⁵

Kw = 10⁻¹⁴

Given that the dissolution of NH₄Cl gives NH₄⁺⁺ and Cl⁻ ions the equation is written as :

NH₄CI  +  H₂O  ⇄  NH₃ + H₃O⁺

where conc of H₃O⁺

[ H₃O⁺ ] = [tex]\sqrt{Ka.C}[/tex]   and Ka = Kw / Kb

∴ Ka = 5.56 * 10⁻¹⁰

Next step : Determine the concentration of H₃O⁺  in the solution

pH = - log [ H₃O⁺ ] = 4.85

∴ [ H₃O⁺ ] in the solution = 1.14125 * 10⁻⁵

Next step : Determine the concentration of NH₄CI in the solution

C = [ H₃O⁺ ]² / Ka

  = ( 1.14125 * 10⁻⁵ )² /  5.56 * 10⁻¹⁰

  = 0.359 mol / L

Determine the number of moles of NH₄CI in the solution

n = C . V

  = 0.359 mol / L  * 0.25 L =  0.08979 mole

Final step : determine the mass of ammonium chloride that must be added to 250 mL

mass = n * molar mass

         = 0.08979 * 53.5 g/mol

         = 4.80 g  ≈ 4.7 grams

Therefore we can conclude that the mass of ammonium chloride that must be added is 4.7 g

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The molecule C2F4 has a trigonal planar molecular and electron pair geometry.

The shape of a molecule is dependent on the number of electron pairs that surround the central atom in the molecule. In the molecule C2F4, there are two central carbon atoms.

Each of the central carbon atoms have a trigonal planar molecular and electron pair geometry. C2F4 is a symmetrical molecule so it is nonpolar and has a zero dipole moment.

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There are 6.44 × 10²³ molecules in 24.0 L of oxygen gas at standard temperature and pressure.

HOW TO CALCULATE NUMBER OF MOLECULES:

To calculate the number of molecules in a substance, we need the number of moles. The number of moles can be calculated using ideal gas law equation as follows:

PV = nRT

Where;

According to this question, oxygen gas is at standard temperature (273K) and pressure (1 atm)

1 × 24 = n × 0.0821 × 273

24 = 22.4n

n = 24 ÷ 22.4

n = 1.07moles

To calculate the number of molecules, we multiply the no. of moles by Avogadro's number (6.02 × 10²³)

no. of molecules = 1.07 × 6.02 × 10²³

no. of molecules = 6.44 × 10²³

Therefore, there are 6.44 × 10²³ molecules in 24.0 L of oxygen gas at standard temperature and pressure.

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Equilibrium concentration of HOCl at 25°C is 0.140 M

The equation of the reaction at equilibrium is given below:

H₂O (g) + Cl₂O (g) ⇄ 2 HOCl (g)

Equilibrium constant, Kc = 0.0900 at 25°C

An ICE chart for the reaction is set up below

     H₂O (g)  +  Cl₂O (g)   ⇄  2 HOCl (g)

I     0.384        0.384             0.652

C     -x                -x                   + 2x

E    0.384 - x   0.384 - x       0.652 + 2x

The equation of the equilibrium constant is given as;

Kc = [tex]\frac{[HOCl]^2}{[H_{2}O][Cl_{2}O]}[/tex]

substituting the values into the equation:

Kc = [tex]\frac{(0.652 + 2x)^2}{( 0.384 - x)( 0.384 - x)}[/tex] = 0.0900

4x² + 2.608x + 0.425 = 0.0900 (0.147 - 0.768x + x²)

4x² - 0.09x² + 2.677x - 0.069x + 0.425 - 0.013 = 0

3.910x² + 2.677x + 0.412 = 0

Solving using the quadratic formula:

a = 3.910, b = 2.677, c = 0.412

x = [tex]\frac{-2.677\±\sqrt{2.677^2 - 4*3.910*0.412}}{2*3.910}[/tex]

x = -0.256 or -0.431

The negative sign indicates that equilibrium is to the left of the reaction

Since x cannot be greater than 0.384, x = -0.256.

Equilibrium concentration of HOCl = 0.652 + 2(-0.256)

Equilibrium concentration of HOCl at 25°C is 0.140 M

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Answer:

The basic unit of the nervous system is a nerve cell or neuron. The nervous system transmits signals between the brain and the rest of the body, this way, the nervous system's activity controls the ability to move, breathe, see, and think.

Explanation:

Have a great rest of your day
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The volume of water needed to make the solution is 473.76 mL

We'll begin by calculating the volume of the diluted solution.

M₁V₁ = M₂V₂

15.5 × 5.41 = 0.175 × V₂

83.855 = 0.175 × V₂

Divide both side by 0.175

V₂ = 83.855 / 0.175

V₂ = 479.17 mL

Finally, we shall determine the volume of water needed.

Volume of water = V₂ – V₁

Volume of water = 479.17 – 5.41

Volume of water = 473.76 mL

Therefore, the volume of the water needed is 473.76 mL

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Answer:

Without the hydrosphere, the atmosphere will no longer be able to carry up the evaporated water, as well as pour down the water, leaving the biosphere to rot away. The hydrosphere works with the Biosphere to provide the requirement of water to the organisms needs, as well as the hydrosphere assisting in photosnythesis.

Explanation:

Answer:

The hydrosphere refers to the water on the earth crust. If there were no hydrosphere, we would not have lakes, oceans, rivers, or even a hose full of water. There would also be no life. Nothing can live without water, so nothing would have evolved.  

Explanation:

boron, carbon, nitrogen, oxygen and flourine families in addition to the noble gases.

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also to answer the 'hello guys what is good!':nothin u?

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Answer:

About 7.0 × 10³ J or 7.0 kJ

Explanation:

We want to determine the amount of energy needed to raise the temperature of 67 grams of water from 20°C to 45°C.

We can use the heat equation:

[tex]\displaystyle q = mC\Delta T[/tex]

Where C is the specific heat of water.

Substitute and evaluate:

[tex]\displaystyle \begin{aligned} q & = (67\text{ g})\left(\frac{4.2\text{ J}}{\text{g-$^\circ$C}}\right)\left(45^\circ \text{ C}- 20.^\circ\text{ C}\right) \\ \\ & = (67\text{ g})\left(\frac{4.2\text{ J}}{\text{g-$^\circ$C}}\right)(25^\circ \text{ C}) \\ \\ & = 7.0\times 10^3 \text{ J}\end{aligned}[/tex]

Recall that there are 1000 J in a kJ. Hence:

[tex]\displaystyle \begin{aligned} q & = 7.0\times 10^3 \text{ J} \cdot \frac{1\text{ kJ}}{1000\text{ J}} \\ \\ & = 7.0 \text{ kJ}\end{aligned}[/tex]

In conclusion, it will take about 7.0 × 10³ J or 7.0 kJ of energy to raise the temperature of 67 grams of water from 20 °C to 45 °C.

Answer:

The answer would be oxygen.

Answer:

There are 27 Valence electrons : )

4+1+1+1+6+4+1+1+4+1+1+1 is 27

Explanation:

There are a total of [5×1]+[2×4]+[7]=21[5×1]+[2 × 4 ] + [ 7]=21 valence electrons

Answer:

yes here is the answer key

for the last question it is a challenge question, here is the answer:

(A) The mass of the cart is 1.214 kg

(B) The mass of one fan is 1.262 kg

(C) The mass of one of the draggable mass units is 3.131 kg

Explanation:

Answer:

The answer is C

Explanation:

Just took the test

Hydrogen bonding is the intermolecular interaction that occurs due to electronegativity differences. Substance B has stronger bonds and requires more energy. Thus, option B is correct.

Hydrogen bonding is present in the water molecules that is because of the electronegativity differences and the dipole-dipole interaction. The hydrogen of the water molecule is bonded to the oxygen molecule.

The hydrogen bonding affects the boiling and the melting point of the substances as more energy are required to change the phase of the matter. So when substance B requires 100ºC than substance A (78.4ºC) it shows strong hydrogen bonding.

Therefore, option B. substance B has a strong hydrogen bond is correct.

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Answer:

Ionic bond occurs between two atoms that have different:

a) Electron

Explanation:

according to the definition of ionic bond,

it is the electrostatic force of attraction that holds the two oppositely charged ions together and an ionic bond or electrovalent bond is formed when one atom gains electrons while the other atom loses electrons from its outermost level or orbit.

Answer:

I think that is the literal answer

Answer:

False

Explanation:

Fluid pressure has no direction, being a scalar quantity, whereas the forces due to pressure have well-defined directions: They are always exerted perpendicular to any surface. The reason is that fluids cannot withstand or exert shearing forces.

Answer:

Vitamins are classified as either fat soluble (vitamins A, D, E and K) or water soluble (vitamins B and C). This difference between the two groups is very important. It determines how each vitamin acts within the body.