please help me quickly ????

Calculate the equilibrium solubility of silver arsenate

(Ksp = 6 * 10-23) in a solution that buffered to a pH of :

a) 3

b) 6

c) 9

For H3ASO4

Ka1 = 5 * 10-3

Ka2 = 1.1 * 10-7

Ka3 = 3.2 * 10-12​

Answer: A balanced chemical equation, including physical state symbols, for the decomposition of solid sodium azide ([tex]NaN_{3}[/tex]) into solid sodium and gaseous dinitrogen is [tex]2NaN_{3}(s) \rightarrow 2Na(s) + 3N_{2}(g)[/tex].

Explanation:

A chemical equation which contains same number of atoms on both reactant and product side is called a balanced chemical equation.

For example, [tex]NaN_{3}(s) \rightarrow Na(s) + N_{2}(g)[/tex]

Here, number of atoms present on reactant side are as follows.

Number of atoms present on product side are as follows.

To balance this equation, multiply [tex]NaN_{3}[/tex] by 2 on reactant side. Also, multiply Na by 2 and [tex]N_{2}[/tex] by 3 on product side.

The equation will be rewritten as follows.

[tex]2NaN_{3}(s) \rightarrow 2Na(s) + 3N_{2}(g)[/tex]

This equation contains same number of atoms on both reactant and product side. Hence, this equation is now balanced.

The symbols (s) and (g) depicts the physical state of substances present in the equation as solid and gas.

Thus, we can conclude that balanced chemical equation, including physical state symbols, for the decomposition of solid sodium azide ([tex]NaN_{3}[/tex]) into solid sodium and gaseous dinitrogen is [tex]2NaN_{3}(s) \rightarrow 2Na(s) + 3N_{2}(g)[/tex].

The question is incomplete, the complete question is;

Assume that your empty crucible weighs 15.98 g, and the crucible plus the sodium bicarbonate sample weighs 18.56 g. After the first heating, your crucible and contents weighs 17.51 g. After the second heating, your crucible and contents weighs 17.50 g.

What is the theoretical yield of sodium carbonate?

What is the experimental yield of sodium carbonate?

What is the percent yield for sodium carbonate?

Which errors could cause your percent yield to be falsely high, or even over 100%?

Answer:

See Explanation

Explanation:

We have to note that water is driven away after the second heating hence we are concerned with the weight of the pure dry product.

Hence;

From the reaction;

2 NaHCO3 → Na2CO3(s) + H2O(l) + CO2(g)

Number of moles of  sodium bicarbonate = 18.56 - 15.98 = 2.58 g/87 g/mol

= 0.0297 moles

2 moles of sodium bicarbonate yields 1 mole of sodium carbonate

0.0297 moles of 0.015 moles  sodium bicarbonate yields 0.0297 * 1/2 = 0.015 moles

Theoretical yield of sodium carbonate = 0.015 moles * 106 g/mol = 1.59 g

Experimental yield of sodium bicarbonate = 17.50 g - 15.98 g = 1.52 g

% yield = experimental yield/Theoretical yield * 100

% yield = 1.52/1.59 * 100

% yield = 96%

The percent yield may exceed 100% if the water and CO2 are not removed from the system by heating the solid product to a constant mass.

The correct question is: 10 kg of R-134a at 300 kPa fills a rigid container whose volume is 14 L. Determine the temperature and total enthalpy in the container. The container is now heated until the pressure is 600 kPa. Determine the temperature and total enthalpy when the heating is completed.

Answer: The temperature is [tex]21.6^{o}C[/tex] and total enthalpy when the heating is completed is 300 kJ.

Explanation:

Given: Mass = 10 kg

Volume = 14 L

Final pressure = 600 K

First, convert volume from L to [tex]m^{3}/kg[/tex] as follows.

[tex]v_{1} = \frac{14 \times 10^{-3}}{10}\\= 0.0014 m^{3}/kg[/tex]

According to the R-134a tables at 300 kPa and [tex]0.0014 m^{3}/kg[/tex].

[tex]h_{1}[/tex] = 54.6 kJ/kg

[tex]T_{sat}[/tex] = 0.7 C

[tex]u_{1}[/tex] = 54.1 kJ/kg

Now, at the state 2 [tex]p_{2}[/tex] = 600 kPa and [tex]v_{2} = v_{1} = 0.0014 m^{3}/kg[/tex]

This means that the final temperature at state 2 is [tex]T_{2} = T_{sat} = 21.6^{o}C[/tex]

Hence, the change in enthalpy is calculated as follows.

[tex]\Delta H = m(h_{2} - h_{1})\\= 10(84.6 - 54.6)\\= 300 kJ[/tex]

The first law is applied to transfer the heat transfer as follows.

[tex]Q = m(u_{2} - u_{1})\\= 10(83.8 - 54.1) kJ\\= 297 kJ[/tex]

Thus, we can conclude that the temperature is [tex]21.6^{o}C[/tex] and total enthalpy when the heating is completed is 300 kJ.

Answer:

874.89 mmHg

Explanation:

Using the combined gas law equation as follows:

P1V1/T1 = P2V2/T2

Where;

P1 = initial pressure (mmHg)

P2 = final pressure (mmHg)

V1 = initial volume (L)

V2 = final volume (L)

T1 = initial temperature (K)

T2 = final temperature (K)

Based on the information provided in this question;

P1 = 950 mm Hg

P2 = ?

V1 = 25 L

V2 = 30 L

T1 = 155°C = 155 + 273 = 428K

T2 = 200°C = 200 + 273 = 473K

Using P1V1/T1 = P2V2/T2

950 × 25/428 = P2 × 30/473

23750/428 = 30P2/473

55.49 = 0.063P2

P2 = 55.49 ÷ 0.063

P2 = 874.89 mmHg

Answer:

Nitrogen molecule (N2)

The electronic configuration of nitrogen (Z=7) = 1s2 2s2 2px12py12pz1.

The total number of electrons present in the nitrogen molecule (N2) is 14.

In order to maximize energy, these 14 electrons can be accommodated in the different molecular orbitals.

N2: KK'(σ2s)2 (σ*2s)2 (π2Px)2 (π2py)2 (σ2pz)2

Here (σ1s)2 (σ*1s)2 part of the configuration is abbreviated as KK’, which denotes the K shells of the two atoms. In calculating bond order, we can ignore KK’, as it includes two bonding and two antibonding electrons.

The bond order of N2can be calculated as follows:

Here, Nb = 10 and Na = 4

Bond order = (Nb−Na) /2

B.O = (10−4)/2

B.O = 3

So your answer should be C3.

Light energy travels in the form of waves.

Answer:

just look at what row the element is in. The lower the row, the bigger the radius

Explanation:

Answer:

30 hot dogs

Explanation:

It is given that :

There are 4 packets of eight wieners, i.e. 4 x 8 = 32 wieners

There are 3 bags of ten buns, i.e. 3 x 10 = 30 buns

One hot dogs need 1 bun and 1 wiener to make a hot dog.

There are 30 buns, so 30 hot dogs can be made out by using all the 30 buns and the 30 wieners out of the 32 wieners.

Therefore, 30 hot dogs.

And the number of extra wieners left = 32 - 30 = 2 wieners.

Answer:

Hi, there your answer is A. As the frequency of a wave increases, the shorter its wavelength is.

Explanation:

When frequency increases, wavelength decreases.

Hope this Helps :)

Answer:

Sulphide ion(S-²) has a -2 charge

Ammonium (NH4+¹) has a +1 charge

When Exchange of Radicals Occur..

The compound formed is

(NH4)2S.

OPTION A IS YOUR ANSWER!

Answer:

NH4)2S

So it is A

Explanation:

l love my life an I am happy with it

Answer:

pH = 2.66

Explanation:

First we calculate the number of moles of each reactant, using the given volumes and concentrations:

We calculate how many acetic acid moles remain after the reaction:

We now calculate the molar concentration of acetic acid after the reaction:

27.5 mmol / (50.0 mL + 10.0 mL) = 0.458 M

Then we calculate [H⁺], using the following formula for weak acid solutions:

Finally we calculate the pH:

Answer:

a. 6 grams

b. 108 grams

c. 2 grams

d. 54 grams

Answer:

Explanation:

The density of a substance can be found by using the formula

[tex]d = \frac{m}{v} \\ [/tex]

We have

[tex]d = \frac{1.25 \times {10}^{2} }{51} \\ = 2.45098..[/tex]

We have the final answer as

Hope this helps you

Answer:

Calcium (Ca) - will lose electrons

Sulfur (S) - will gain electrons

Carbon (C) could lose or gain electrons

Neon (Ne) Does not gain or lose electrons

Answer:

the correct answer is 12 sides (:

Explanation:

Answer:

See explanation

Explanation:

The molecular equation shows all the compounds involved in the reaction.

The molecular equation is as follows;

2NaF(aq) + Pb(NO3)2(aq) -------> PbF2(s) + 2NaNO3(aq)

The complete ionic equation shows all the ions involved in the reaction

The complete ionic equation;

2Na^+(aq) + 2F^-(aq) + Pb^2+(aq) + 2NO3^-(aq) -------->PbF(s) + 2Na^+(aq) +2NO3^-(aq)

The net Ionic equation shows the ions that actually participated in the reaction

The net ionic equation is;

2F^-(aq) + Pb^2+(aq)--------> PbF(s)

Answer:

80%

Explanation:

Water is essential for all the body functions like digestion

We should drink water so that we will have a healthy body

Stay safe and healthy :)

Answer:

chlorous acid

Explanation:

The acidic equilibrium of weak acids, HX, occurs as follows:

HX ⇄ H+ + X-

Where Ka is written as:

Ka = [H+] [X-] / [HX]

The strongest acid is the acid that produce more H+. The acid with the higher Ka is the acid that produce more [H+] and is, thus, the strongest acid.

The higher Ka is the Ka of chlorus acid = 1.2x10-2

Right answer is:

Answer:

chlorous acid :)

Explanation:

Answer:

3

Explanation:

potassium is a highly electropositive metal with one electron for bonding, it reacts with a highly electro negative non metal like chlorine to give an electrovalent or ionic bonding

Answer:

5.9 g

Explanation:

Step 1: Write the balanced reaction for the photosynthesis

6 CO₂ + 6 H₂O ⇒ C₆H₁₂O₆ + 6 O₂

Step 2: Calculate the moles of CO₂

We have 5.0 L of CO₂ at 32 °C (305 K) and 750 mmHg. We can calculate the moles of CO₂ using the ideal gas equation.

P × V = n × R × T

n = P × V/R × T

n = 750 mmHg × 5.0 L/(62.4 mmHg.L/mol.K) × 305 K = 0.20 mol

Step 3: Calculate the moles of C₆H₁₂O₆ produced from 0.20 moles of CO₂

The molar ratio of CO₂ to C₆H₁₂O₆ is 6:1. The moles of C₆H₁₂O₆ produced are 1/6 × 0.20 mol = 0.033 mol

Step 4: Calculate the mass corresponding to 0.033 moles of C₆H₁₂O₆

The molar mass of C₆H₁₂O₆ is 180.16 g/mol.

0.033 mol × 180.16 g/mol = 5.9 g

Today, as part of the series of posts on soils, we are going to look at ‘soil texture’. Soil forms the basis for all life but it’s important to know about its mineral constitution as well as its biological profile.

Texture refers to the ‘feel’ of the soil. This is affected by the constituent materials found within it, specifically sand, silt and clay particles. A coarse sand will feel gritty but a wet clay will feel heavy and sticky. The texture of a soil has a direct impact on the way the soil reacts to certain environmental conditions – for example, towards drought or heavy rain (with sandy soils more freely draining).

There is a big difference in the size of the different particles.

Coarse sand = diameter 2-0.2mm

Fine sand = diameter 0.2-0.02mm

Silt = diameter 0.02-0.002mm

Clay = diameter less than 0.002mm

Note how the clay particles are much smaller than the sand particles – this is important as it means the total surface area of a clay soil is much greater and so the capacity to hold water is also much greater.

Between the sand, silt and clay particles there are lots of pores. In fact a soil as a whole is generally 45% mineral, 5% organic matter (depending on the soil) and 50% pore space through which air and water can pass.

Sand –

Made up of weathered primary rock minerals.

The particles are irregular in outline.

They are large and so do not pack together easily.

Large pore spaces in between.

Air gets in very easily and water flows rapidly through it.

Silt –

Answer:

circulatory and excretory

could you theoretically cook methamphetamine? just wonderkng.

Answer:

Explanation

i k the ansewer

Answer:

Explanation:

The pH of a solution can be found by using the formula

[tex]pH = - log [ { H}^{+}][/tex]

From the question we have

[tex]ph = - log(9.25 \times {10}^{ - 5} ) \\ = 4.03385[/tex]

We have the final answer as

Hope this helps you

Explanation:

The self-ionization of water (also autoionization of water, and autodissociation of water) is an ionization reaction in pure water or in an aqueous solution, in which a water molecule, H2O, deprotonates (loses the nucleus of one of its hydrogen atoms) to become a hydroxide ion, OH−. The hydrogen nucleus, H+, immediately protonates another water molecule to form hydronium, H3O+. It is an example of autoprotolysis, and exemplifies the amphoteric nature of water

Animation of the self-ionization of water

Chemically pure water has an electrical conductivity of 0.055 μS/cm. According to the theories of Svante Arrhenius, this must be due to the presence of ions. The ions are produced by the water self-ionization reaction, which applies to pure water and any aqueous solution:

H2O + H2O ⇌ H3O+ + OH−

Expressed with chemical activities a, instead of concentrations, the thermodynamic equilibrium constant for the water ionization reaction is:

{\displaystyle K_{\rm {eq}}={\frac {a_{\rm {H_{3}O^{+}}}\cdot a_{\rm {OH^{-}}}}{a_{\rm {H_{2}O}}^{2}}}}

which is numerically equal to the more traditional thermodynamic equilibrium constant written as:

{\displaystyle K_{\rm {eq}}={\frac {a_{\rm {H^{+}}}\cdot a_{\rm {OH^{-}}}}{a_{\rm {H_{2}O}}}}}

under the assumption that the sum of the chemical potentials of H+ and H3O+ is formally equal to twice the chemical potential of H2O at the same temperature and pressure.[1]

Because most acid–base solutions are typically very dilute, the activity of water is generally approximated as being equal to unity, which allows the ionic product of water to be expressed as:[2]

{\displaystyle K_{\rm {eq}}\approx a_{\rm {H_{3}O^{+}}}\cdot a_{\rm {OH^{-}}}}

In dilute aqueous solutions, the activities of solutes (dissolved species such as ions) are approximately equal to their concentrations. Thus, the ionization constant, dissociation constant, self-ionization constant, water ion-product constant or ionic product of water, symbolized by Kw, may be given by:

{\displaystyle K_{\rm {w}}=[{\rm {H_{3}O^{+}}}][{\rm {OH^{-}}}]}

where [H3O+] is the molarity (≈ molar concentration)[3] of hydrogen or hydronium ion, and [OH−] is the concentration of hydroxide ion. When the equilibrium constant is written as a product of concentrations (as opposed to activities) it is necessary to make corrections to the value of {\displaystyle K_{\rm {w}}} depending on ionic strength and other factors (see below).[4]

At 25 °C and zero ionic strength, Kw is equal to 1.0×10−14. Note that as with all equilibrium constants, the result is dimensionless because the concentration is in fact a concentration relative to the standard state, which for H+ and OH− are both defined to be 1 molal (or nearly 1 molar). For many practical purposes, the molal (mol solute/kg water) and molar (mol solute/L solution) concentrations can be considered as nearly equal at ambient temperature and pressure if the solution density remains close to one (i.e., sufficiently diluted solutions and negligible effect of temperature changes). The main advantage of the molal concentration unit (mol/kg water) is to result in stable and robust concentration values which are independent of the solution density and volume changes (density depending on the water salinity (ionic strength), temperature and pressure); therefore, molality is the preferred unit used in thermodynamic calculations or in precise or less-usual conditions, e.g., for seawater with a density significantly different from that of pure water,[3] or at elevated temperatures, like those prevailing in thermal power plants.

We can also define pKw {\displaystyle \equiv } −log10 Kw (which is approximately 14 at 25 °C). This is analogous to the notations pH and pKa for an acid dissociation constant, where the symbol p denotes a cologarithm. The logarithmic form of the equilibrium constant equation is pKw = pH + pOH.

Answer:

There is one valence electron in a neutral lithium atom.

Explanation:

The number of valence electrons in a neutral lithium atom is equal to one.

Valence electrons can be described as the electrons filling the outermost shell of an atom while the electrons in the inner shell of an atom are known as core electrons. Lewis structures are used to determine the number of valence electrons and know the types of chemical bonds.

Valence electrons of an atom can be filled in the same or different orbitals and these electrons are responsible for the interaction between atoms and cause the formation of chemical bonds.

Only electrons occupied in the outermost shell can participate in the formation of a bond or a molecule and are responsible for the reactivity of the element.

The number of electrons in the neutral atom of lithium is 3. There is only one electron present on the outermost shell 2s-orbital.

Learn more about valence electrons, here:

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