How much heat is liberated (in kJ) from 249 g of silver when it cools from 87 °C to 26 °C? The heat capacity of silver is 0.235 Jg^{-1} °C^{-1}. Note, "heat liberated" implies that the change in heat is negative. Enter a positive number.

Answer:

Which equation represents the reaction of a weak acid with water?  the equation is : HCl + H2O H3O+ + Cl- HCO3– + H2O H2CO3 + OH– H2O H + + OH- HCOOH + H2O H3O+ + HCOO

Explanation:

hope it helps : )

Answer:

Hey mate, here is your answer. Hope it helps you.

HCOOH + H2O ↔ H3O+ + HCOO-

Explanation:-

A strong acid is one which completely dissociates into its corresponding ions in aqueous medium.

In contrast,  a weak will only partially dissociate such that there is an equilibrium between the dissociated ions and the undissociated acid.

In the given examples:

HCl, HCO3- and H2CO3 are all strong acids. However, HCOOH i.e. formic acid is a weak acid which dissociates in water to form H3O+ and formate ion, HCOO-

HCOOH + H2O ↔ H3O+ + HCOO-

Answer:

38.96383282 amu

Explanation:

39.0983 = (40.9618 [tex]\times[/tex] 0.067302) + ( ? [tex]\times[/tex] (1-0.067302)

39.0983 = 2.756811064 + ( ? [tex]\times[/tex] 0.932698)

subtract 2.756811064 from both sides

36.34148894 = ( ? [tex]\times[/tex] 0.932698)

divide both sides by 0.932698

? = 38.96383282 amu

Answer:

38.96383282 amu

Explanation:

39.0983 = (40.9618  0.067302) + ( ?  (1-0.067302)

39.0983 = 2.756811064 + ( ?  0.932698)

subtract 2.756811064 from both sides

36.34148894 = ( ?  0.932698)

divide both sides by 0.932698

? = 38.96383282 amu

Explanation:

The answer is the Calcium ion. It satisfies the conditions of the question.

Condition 1

The net ionic charge is one-tenth the nuclear charge.

In the Calcium ion,  Ca²⁺. The nuclear charge in this ion is 20. The net ionic charge is 2.

2 / 20 = 1 / 10. So the net ionic charge is indeed one tenth of the nuclear charge.

Condition 2

The number of neutrons is four more than the number of electrons.

Mass Number of Ca²⁺ = 44

Atomic Number = 20

Neutrons =  Mass Number - Atomic Number = 44 -20 = 24

Number of electrons = 20 - 2 = 18

Since Number of Neutrons = 22, Number of electrons = 18. This condition also holds.

As an ion and as an isotope = Ca²⁺, Ca - 42

Answer:

ΔGrxn for the reaction A(g)→B(g) will most likely to be negative under the PA=10.0atm ; PB=0.050atm condition

The FIRST option is correct

Explanation:

From Thermodynamics,

Using the Gibbs Free Energy (G) formula to determine the reaction A(g)→B(g) most likely to be negative.

Gibbs Free Energy (G) which is the energy associated with a chemical reaction that can be used to do work.

CHECK THE ATTACHMENT FOR THE DETAITALED EXPLANATION

Answer:

solubility is 1.984x10⁻⁹M

Explanation:

When CaCO₃ is in water, the equilibrium that occurs is:

CaCO₃(s) ⇄ Ca²⁺(aq) + CO₃²⁻(aq)

Kps = [Ca²⁺] [CO₃²⁻] = 4.96x10⁻⁹

If you have a 0.250M solution of Na₂CO₃, [CO₃²⁻] = 0.250M:

[Ca²⁺] [0.250M] = 4.96x10⁻⁹

Assuming you are adding an amount of CaCO₃:

[X] [0.250 + X] = 4.96x10⁻⁹

Where X is the amoun of CaCO₃ you can add, that means, solubility

X² + 0.250X - 4.96x10⁻⁹ = 0

Solving for X:

X = -0.25M → False answer, there is no negative concentrations.

X = 1.984x10⁻⁹M.

That means, solubility is 1.984x10⁻⁹M

Answer:

[tex]1.984x10^{-8}M[/tex]

Explanation:

Hello,

In this case, the equilibrium reaction for the solubility of calcium carbonate is:

[tex]CaCO_3(s) \rightleftharpoons Ca^{2+}(aq)+CO_3^{-2}(aq)[/tex]

In such a way, since 0.250 M sodium carbonate solution is the solvent, we assume an initial concentration of carbonate anion to be also 0.250 M since sodium carbonate is completely dissolved, for that reason the equilibrium equation turns out:

[tex]Ksp=[Ca^{2+}][CO_3^{2-}]\\\\4.96x10^{-9}=x*(0.250+x)[/tex]

Hence, solving for [tex]x[/tex] we have:

[tex]x=1.984x10^{-8}M[/tex]

Which corresponds to the molar solubility if calcium carbonate as well.

Regards.

Answer:

Explanation:

One CH4 molecules = 10 electrons ( Carbon 6e + 4Hydrogen 4e)

A mole of any substance witll have = 6.023*10^23 atom/ molecuels,

One mole of any substnce is equal is nothing but its moalr mass

Molar mass of CH4 = 16.04

It mean,

16.04  g of CH4 has = 6.023*10^23 molecules of methane

but

4.2 gram of CH4   = 6.023*10^23 * 4.2 /16.04 = 1.58*10^23 molecuels of CH4

So one molecule has =10 electrons

1.58*10^23 molecuels will have = 1.58*10^23  * 10 = 1.58*10^24

Hope this help you

Answer:

87.3

Explanation:

To calculate the relative atomic mass

((84.9*15)+(86.9*12.9)+(87.9*72.1))/15+12.9+72.1

(1273.5 + 1121.01 + 6337.59) / 100

8732.1/100

87.321 = 87.3

Answer:

growth hormone is ur answer

Answer:

Explanation:

two hormones are secreted from posterior lobe i.e. oxytocin and vasopressin

Answer:

[tex]V_{HCl}=80mL[/tex]

Explanation:

Hello,

In this case, for the given reactants we identify the following chemical reaction:

[tex]KOH+HCl\rightarrow KCl+H_2O[/tex]

Thus, we evidence a 1:1 molar ratio between KOH and HCl, therefore, for the complete neutralization we have equal number of moles, that in terms of molarities and volumes become:

[tex]n_{HCl}=n_{KOH}\\\\M_{HCl}V_{HCl}=M_{KOH}V_{KOH}[/tex]

Hence, we compute the volume of HCl as shown below:

[tex]V_{HCl}=\frac{M_{KOH}V_{KOH}}{M_{HCl}} =\frac{0.40M*40mL}{0.20M} \\\\V_{HCl}=80mL[/tex]

Best regards.

Answer:

because no 2 or 3 bond so it is saturated

Answer:

A

Explanation:

Answer:

(D) - 16.6 kcal

Explanation:

Hello,

In this case, the Gibbs free energy for the given reaction is computed in terms of the Gibbs free energy of formation of each species involved in the chemical reaction:

[tex]\Delta _rG=2\Delta _fG_{NO_2}-2\Delta _fG_{NO}-\Delta _fG_{O_2}[/tex]

Thus, it is found for nitrogen monoxide, oxygen and nitrogen dioxide the following Gibbs free energies of formation: 87.6, 0 and 51.3 kJ/mol respectively, therefore we compute:

[tex]\Delta _rG=2(51.3kJ/mol)-2(87.6kJ/mol)=-72.6kJ*\frac{1kcal}{4.184kJ} \\\\\Delta _rG=-17.35kcal[/tex]

The closest result is (D) - 16.6 kcal, as such difference is noticed when different sources for thermochemical data are used, in this case, the NIST data were used.

Best regards.

Answer:

THE MOLECULAR FORMULA FOR THE COMPOUND IS C2 Cl2

Explanation:

mass = 0.04380 g

Volume = 10 mL = 10 / 1000 L = 0.010 L

Pressure = 1.10 atm

R = 0.082 L atm mol^-1 K^-1

Temperature = 290.5 K

Carbon = 25.305 %

Chlorine = 74.695 %

Atomic mass of carbon = 12

Atomic mass of chlorine = 35.5

First calculate the empirical formula by following these steps:

1. Write the percentage composition of the elements involved and divide by its atomic mass

Carbon = 25.305 / 12 = 2.10875

Chlorine = 74.695 /35.5 = 2.1040

2. Divide each by the smaller value

Carbon = 2.10875 / 2.1040 = 1.002

Chlorine = 2.1040 / 2.1040 = 1

3. Round up to the whole number

The empirical formula is C Cl

Next is to calculate the molar mass of the compound using ideal gas equation

PV = mRT/ MM

Mm = mRT / PV

Mm = 0.04380 * 0.082 * 290.5 / 1.10 * 0.010

Mm = 1.0433 / 0.011

Mm = 94.845 g/mol

Mm = 94.85 g/mol

Now that we know the molar mass, we can go on to calculate the molecular formula:

(C Cl) n = Molar mass

( 12 + 35.5) n = 94.85

(47.5)n = 94.85

n = 94.85 / 47.5

n = 1.9968

n ~ 2

The molecular formula can then be written as C2Cl2.

Answer:

the reaction associated with the ionization energy of lithium

Explanation:

An endothermic process is any process which requires or absorbs energy from its surroundings, usually in the form of heat.

the reaction associated with the ionization energy of lithium:

Ionization energy is endothermic because it requires an energy input to occur, we need to supply energy to remove that outermost electron.

the formation of CO2 from its elements in their standard states:

This reaction is exothermic, heat is released per mole of CO2 formed.

the reaction associated with the heat of formation of Sr S:

Heat is giving off, so the process is an exothermic process.

the reaction associated with the lattice energy of Na Br:

Lattice energy is exothermic. Lattice energy is the energy released when gaseous cations and anions associate with each other to form a solid.

Explanation:

H

|

H-C=C-C-OH

| | |

H H H

in this organic compound the functional groups are OH and alkene

prop-2-enol

since it has a double bond, alkene is the functional group. and also it has OH group so hydroxyl group also the other functional group

Complete Question

The complete question is shown on the first uploaded image

Answer:

 The kinetic order in HI is x=  2

Explanation:

Generally the slow step in a reaction mechanism is the rate determining step

  Now with this knowledge at the back of our minds we can see that  the number of moles of HI i s 2 which implies that the order of HI is 2m

So we can represent the rate law as

        [tex]Rate = k [CH_3 CHCH_2][HI]^2[/tex]

hence

x =  2

Answer:

1.20 × 10⁻³ mol e⁻

Explanation:

There is some info missing. I think this is the original question.

Suppose a current of 0.880 A flows through a copper wire for 132 seconds. Calculate how many moles of electrons travel through the wire. Be sure your answer has the correct unit symbol and round your answer to significant digits.

Step 1: Given data

Step 2: Calculate the charge, in Coulomb, that travel through the wire

We will find the circulating charge (q) using the following expression.

[tex]q = I \times t = \frac{0.880C}{s} \times 132s = 116C[/tex]

Step 3: Calculate the moles of electrons with a charge of 116 C

We will use the relationship 1 mole of electrons = 96,486 C (Faraday's constant)

[tex]116C \times \frac{1mol\ e^{-} }{96,486 C} =1.20 \times 10^{-3} mol\ e^{-}[/tex]

In order to use the energy stored in fat, the body breaks dow triglycerides into fatty acids, which individual cells burn for energy

Answer:

ATGGCCTA

Explanation:

For this we have to keep in mind that we have a specific relationship between the nitrogen bases:

-) When we have a T (thymine) we will have a bond with A (adenine) and viceversa.

-) When we have C (Cytosine) we will have a bond with G (Guanine) and viceversa.

Therefore if we have: TACCGGAT. We have to put the corresponding nitrogen base, so:

TACCGGAT

ATGGCCTA

I hope it helps!

Answer:

CuI₂ + Br₂

Explanation:

Answer:

CuI₂ + Br₂

Explanation:

1) The activity series F > Cl > Br > I means that F is the most active and I is the least active of those four elements (the halogens, group 17 in the periodic table).

The activity is a measure of how eager is an element to react compared to other elements in the series in a single replacement reaction.

2) Choice 1: CuI₂ + Br₂

Since the activity of Br is higher than that of I, Br will react with CuI₂, displacing I, which will be left alone, as per this chemical equation:

CuI₂ + Br₂ → CuBr₂ + I₂

Being I less active than Br, it cannot displace Br in CuBr₂.

3) Choice 2: Cl₂ + AlF₃

Being Cl less active than F, the former will not displace the latter, and the reaction will not proceed.

4) Choice 3: Br₂ + NaCl

Again, being Br less active than Cl, the former will not displace the latter, and the reaction will not proceed.

5) Choice 4: CuF₂ + I₂

Once more, being I less active than F, the former will not displace the latter, and the reaction will not proceed.

hope this helped!

Answer:

Kc = 15.25

Explanation:

In this case, As I say in the comments, you are missing the following data of moles and volume which are:

Initial moles of ammonia = 29 mol

Final moles of nitrogen = 13 mol

Volume tank = 75 L

Now, if your data is different, just replace the values and follow the same procedure written here to get the accurate result.

With these data, let's write the equilibrium reaction that is taking place here:

2NH₃ <---------> N₂ + 3H₂     Kc = ?

To get the Kc, we need to use the following expression:

Kc = [N₂] [H₂]³ / [NH₃]²

This expression is only usable when we reach the equilibrium. But we don't have the concentrations in equilibrium of any species, so, we need to get those values. To get that, we need to do an ICE chart, write the initial and final concentrations given, and then, replace the values.

First, the concentrations of the species are:

[NH₃] = 29 / 75 = 0.3867 M

[N₂] = 13 / 75 = 0.1733 M

Now that we have these values, we will replace them in the ICE chart, and then, rewrite the Kc expression to get that value so:

       2NH₃ <---------> N₂ + 3H₂     Kc = ?

i)     0.3867               0        0

c)       -2x                 +x      +3x

e)   0.3867-2x          x         3x

However, as we already have the value for concentration of nitrogen, this will be the value of "x", therefore, our final values in equilibrium would be:

[NH₃] = 0.3867 - 2(0.1733) = 0.0401 M

[H₂] = 3(0.1733) = 0.5199 M

Now with these values, we can replace them in the Kc expression to get that value so:

Kc = (0.5199)³ * (0.1733) / (0.0401)²

Kc = 0.0244 / 0.0016

Kc = 15.25

And this is the value of Kc for this reaction.

Answer:

Yes that is why you can even see how some chemicals might react but that is if you are not considering temperature, pressure, or if catalyst are involved.

Answer:

(b) When 20.0 g of nitrogen and 32.0 g of oxygen are combined and allowed to react in two separate experiments, both times the product isolated from reaction contains 14.0 g of nitrogen and 32.0 g of oxygen.

Explanation:

The law of definite proportion states that a gen chemical compound always contains its constituent elements in a fixed ratio by mass, independent on the method of preparation.

The molar mass of Nitrogen and Oxygen would always remain the same, allowing for exact reactant masses (or mole ratio) irrespective of the given amount of sample.

Image is not given in the question, so the image for the question is given below.

Answer:

Fischer projection is a two-dimensional representation of a three-dimensional organic molecule by projection.

Wedge and dash bonds are used to represent the three-dimensional structure of a molecule, in which wedges indicates bonds towards the viewer, solid lines indicates bonds in the plane of the image and dashed lines indicates bonds away from the viewer.

Wedge and dash bonds structure of D-glyceraldehyde is attached below.

Answer:

0.24375moles

Explanation:

Moles=mass/moler mass

Fe-56

O-16

(56×2)+(16×4)

=176

42.9÷176=0.24375moles

Answer: 44.8 L

Explanation:

To find the volume, we would need to use the ideal gas law.

Ideal Gas Law: PV=nRT

We take the given information and plug it into the equation, but first, we have to manipulate the equation so that we are finding volume.

[tex]V=\frac{nRT}{P}[/tex]

P= 1.00 atm (STP)

T= 273.15 K (STP)

R= 0.08206 Latm/Kmol

n= [tex]64g*\frac{1mol}{31.998 g O_{2} }=2 mol[/tex]

[tex]V=\frac{(2 mol)(0.08206Latm/Kmol)(273.15 K)}{1.00atm} =44.8 L[/tex]

Answer:

The rate at which dihydrogen gas is being produced = 0.018 kg/s

Explanation:

Firstly, we write the balanced equation for the production of the synthesis gas

CH₄ + H₂O → CO + 3H₂

The rate of consumption of CH₄ is 159 litres per second. With the reaction ran at T = 294°C and a pressure of 0.86 atm

Using the ideal gas equation, we can convert the volumetric rate of consumption of methane to molar rate of consumption

PV = nRT

PV' = n'RT

P = pressure = 0.86 atm = 87,139.5 Pa

V' = 159 L/s = 0.159 m³/s

n' = ?

R = molar gas constant = 8.314 J/mol.K

T = absolute temperature in Kelvin = 294°C = 567.15 K

87,139.5 × 0.159 = n' × 8.314 × 567.15

n' = (87,139.5 × 0.159) ÷ (8.314 × 567.15)

n' = 2.9383547773 mol/s = 2.938 mol/s

From the stoichiometry of this reaction,

1 mole of methane gives 3 moles of dihydrogen gas

2.938 mol/s of methane will correspond to (3 × 2.938) mol/s of dihydrogen gas, that is, 8.815 mol/s.

Mass flowrate = (molar flowrate) × (molar mass)

Molar flowrate = 8.815 mol/s

Molar mass of dihydrogen gas = 2 g/mol = 0.002 kg/mol

Mass flowrate = 8.815 × 0.002 = 0.0176301287 kg/s = 0.018 kg/s to 2 s.f.

Hope this Helps!!!

Complete Question:

The reform reaction between steam and gaseous methane (CH4) produces "synthesis gas," a mixture of carbon monoxide gas and dihydrogen gas. Synthesis gas is one of the most widely used industrial chemicals, and is the major industrial source of hydrogen.

Suppose a chemical engineer studying a new catalyst for the reform reaction finds that 924. liters per second of methane are consumed when the reaction is run at 261.°C and 0.96atm. Calculate the rate at which dihydrogen is being produced. Give your answer in kilograms per second. Round your answer to 2 significant digits.

Answer:

Rate at which H₂ is produced = 0.12 kg/s

Explanation:

Volume of methane produced, V = 924 litres

Temperature, T = 261.°C = 261 + 273

T = 534 K

Pressure, P = 0.96 atm

Gas constant, R = 0.0821 L-atm/ K-mol

We will calculate the number of  moles of methane used in the reaction.

[tex]n_{methane} = \frac{PV}{RT} \\n_{methane} = \frac{0.96 * 924}{0.0821 * 534} \\n_{methane} = \frac{887.04}{43.8414}\\n_{methane} = 20.23 moles[/tex]

Equation of reaction:

[tex]CH_{4} + H_{2} O \rightarrow CO + 3H_{2}[/tex]

From the reaction above :

1 mole of methane produced 3 moles of H₂

20.23 moles of methane will produce (20.23 * 3 ) moles of H₂

Number of moles of H₂, [tex]n_{H_{2} } = 60.69 moles[/tex]

That is 60.69 moles of hydrogen is produced per second.

Number of moles = Mass/ Molar mass

[tex]n_{H_{2} } = \frac{Mass_{H_{2} }}{Molar mass_{H_{2} }} \\Mass_{H_{2}} = n_{H_{2} } * Molar mass_{H_{2} }\\Mass_{H_{2}} = 60.69 * 2.016\\Mass_{H_{2}} = 122.35 g[/tex]

Rate at which H₂ is produced = 122.35 g/s = 0.12 kg/s

Answer:

B. Cu + 4HNO3 → Cu(NO3)2 + 2H2O + 2NO2

Explanation:

Hello,

In this case, we should understand oxidizing agents as those substances able to increase the oxidation state of another substance, therefore, in B. reaction we notice that copper oxidation state at the beginning is zero (no bonds are formed) and once it reacts with nitric acid, its oxidation states raises to +2 in copper (II) nitrate, thus, in B. Cu + 4HNO3 → Cu(NO3)2 + 2H2O + 2NO2 nitritc acid is acting as the oxidizing agent.

Moreover, in the other reactions, copper (A.), sodium (C. and D.) remain with the same initial oxidation state, +2 and +1 respectively.

Regards.

Answer:

B. Cu + 4HNO3 → Cu(NO3)2 + 2H2O + 2NO2

Explanation:

A substance is acting as oxidising agent when is reducing its chemical state in the reaction.

In HNO3, Nitrogen has an oxidation state of +5 (Each oxygen is -2, 3 oxygens, -6, 1 hydrogen, +1). Thus, if the oxidation state of the nitrogen in the products is < +5, the nitrogen is reducing its oxidation state acting as oxidising agent.

In the reactions:

A. CuO + 2HNO3 → Cu(NO3)2 + H2O . In Cu(NO₃)₂, Nitrogen has an oxidation state of +5. Thus, nitric acid is not acting as oxidising agent.

B. Cu + 4HNO3 → Cu(NO3)2 + 2H2O + 2NO2 . Also, oxidation state in Cu(NO₃)₂ does not have any change but there is another product, NO₂, where nitrogen has an oxidation state of +4. That means nitric acid is acting as oxidising agent.

C. Na2CO3 + 2HNO3 → 2NaNO3 + H2O + CO2 . Here, in NaNO₃, oxidation state of nitrogen is +5 (Na: +1, 3 O: -6). Thus, nitrogen is not changing is oxidation state and nitric acid is not acting as oxidising agent.

D. NaOH + HNO3 → NaNO3 + H2O. Here, also, the product is NaNO₃. That means nitric acid is not acting as oxidising agent.

Answer:

pH =1 2.84

Explanation:

First we have to start with the reaction between HCl and KOH:

[tex]HCl~+~KOH->~H_2O~+~KCl[/tex]

Now for example, we can use a volume of 10 mL of HCl. So, we can calculate the moles using the molarity equation:

[tex]M=\frac{mol}{L}[/tex]

We know that [tex]10mL=0.01L [/tex] and we have the concentration of the HCl [tex]0.282M[/tex], when we plug the values into the equation we got:

[tex]0.282M=\frac{mol}{0.01L}[/tex]

[tex]mol=0.282*0.01 [/tex]

[tex]mol=0.00282[/tex]

We can do the same for the KOH values ([tex]50mL=0.05L[/tex] and [tex]0.141M[/tex]).

[tex]0.141M=\frac{mol}{0.05L}[/tex]

[tex]mol=0.141*0.05 [/tex]

[tex]mol=0.00705[/tex]

So, we have so far 0.00282 mol of HCl and 0.00705 mol of KOH. If we check the reaction we have a molar ratio 1:1, therefore if we have 0.00282 mol of HCl we will need 0.00282 mol of KOH, so we will have an excess of KOH. This excess can be calculated if we substract the amount of moles:

[tex]0.00705-0.00282=0.00423mol~of~KOH[/tex]

Now, if we want to calculate the pH value we will need a concentration, in this case KOH is in excess, so we have to calculate the concentration of KOH. For this, we already have the moles of KOH that remains left, now we need the total volume:

[tex]Total~volume=50mL+10mL=60mL[/tex]

[tex]60mL=0.06L[/tex]

Now we can calculate the concentration:

[tex]M=\frac{0.00423mol}{0.06L}[/tex]

[tex]M=0.0705[/tex]

Now, we can calculate the pOH (to calculate the pH), so:

[tex]pOH=-Log(0.0705)[/tex]

[tex]pOH=1.15[/tex]

Now we can calculate the pH value:

[tex]14=~pH~+~pOH[/tex]

[tex]pH=14-1.15=12.84[/tex]