What is the answer? plz give me the right answer which you are sure of .

Find ΔHrxn for the following reaction: <br><br> 2PbS(s)+3O2(g)→2PbO(s)+2SO2(g)

ch4aika [34]

Answer:

ΔH°rxn = -827.5 kJ

Explanation:

Let's consider the following balanced equation.

2 PbS(s) + 3 O₂(g) → 2 PbO(s) + 2 SO₂(g)

We can calculate the standard enthalpy of reaction (ΔH°rxn) from the standard enthalpies of formation (ΔH°f) using the following expression.

ΔH°rxn = [2 mol × ΔH°f(PbO(s)) + 2 mol × ΔH°f(SO₂(g) )] - [2 mol × ΔH°f(PbS(s)) + 3 mol × ΔH°f(O₂(g) )]

ΔH°rxn = [2 mol × (-217.32 kJ/mol) + 2 mol × (-296.83)] - [2 mol × (-100.4) + 3 mol × 0 kJ/mol]

ΔH°rxn = -827.5 kJ

5 0

3 years ago

At 311 K, this reaction has a K c value of 0.0111 . X ( g ) + 2 Y ( g ) − ⇀ ↽ − 2 Z ( g ) Calculate K p at 311 K. Note that the

Aleks [24]

Answer:

$K_{p}=4.35\times 10^{-4}$

Explanation:

We know, $K_{p}=K_{c}(RT)^{\Delta n}$

where, R = 0.0821 L.atm/(mol.K), T is temperature in kelvin and $\Delta n$ is difference in sum of stoichiometric coefficient of products and reactants

Here $\Delta n=(2)-(2+1)=-1$ and T = 311 K

So, $K_{p}=(0.0111)\times [(0.0821L.atm.mol^{-1}.K^{-1})\times 311K]^{-1}=4.35\times 10^{-4}$

Hence value of equilibrium constant in terms of partial pressure $(K_{p})$ is $4.35\times 10^{-4}$

4 0

3 years ago

You are asked to identify compound X (a white, crystalline solid), which was extracted from a plant seized by customs inspectors

igor_vitrenko [27]

Answer:

C2H2O4

Explanation:

To get the molecular formula, we first get the empirical formula. This can be done by dividing the percentage compositions by the atomic masses. The percentage compositions are shown as follows :

C = 26.86%

H = 2.239%

O = 100 - ( 26.86 + 2.239) = 70.901%

We then proceed to divide by their atomic masses. Atomic mass of carbon is 12 a.m.u , H = 1 a.m.u , O = 16 a.m.u

The division is as follows:

C = 26.86/12 = 2.2383

H = 2.239/1 = 2.239

O = 70.901/16 = 4.4313

We now divide each by the smallest number I.e 2.2383

C = 2.2383/2.2383 = 1

H = 2.239/2.2383 = 1

O = 4.4313/2.2383 = 1.98 = 2

Thus, the empirical formula is CHO2.

To get the molecular formula, we use the molar mass .

(CHO2)n = 90

We add the atomic masses multiplied by n.

(12 + 1 + 2(16))n = 90

45n = 90

n = 90/45 = 2.

Thus , the molecular formula is C2H2O4

4 0

3 years ago

. Write the balanced equation, then outline the steps necessary to determine the information requested in each of the following:

mafiozo [28]

Answer:

See explanation

Explanation:

a) The equation of the reaction is;

2Na + Cl2 ------>2NaCl

Number of moles of sodium = 10g/23 g/mol = 0.43 moles

If 2 moles of sodium reacts with 1 mole of Cl2

0.43 moles reacts with 0.43 * 1/2 = 0.215 moles of Cl2

Mass = 0.215 moles of Cl2 *71 g/mol = 15.265 g

b) Equation of the reaction;

HgO -> Hg + O2

1.252 moles of HgO 1.252/32 gmol = 0.039 moles

1 mole of HgO yields 1 mole of oxygen hence

0.039 moles of HgO yields 0.039 moles of oxygen

Mass of oxygen = 0.039 moles * 32 g/mol = 1.248 g

c) Equation of the reaction;

2NaNO3 -----> 2NaNO2 + O2

Number of moles of 128 g of oxygen = 128g/32 g/mol = 4 moles

2 moles of NaNO3 yields 1 mole of oxygen

x moles of NaNO3 yields 4 moles of oxygen

x = 8 moles of NaNo3

Mass of NaNO3 = 8 * 85 g/mol = 680 g of NaNo3

6 0

3 years ago

The equilibrium expression for a reaction is `"K"_("eq") = ("[H"^+"]"^6)/("[Bi"^(2+)"]"^2["H"_2"S"]^3)` Which of the following c

Nata [24]

Option B is correct

K = Kp /Kr

The given equation indicating, the product containing 6 moles of proton whereas the reactant contains 2 mole of bismuth and 3 mole of hydrogen sulphide.

Hence, in reaction B there are 2 mole of bismuth and 3 mole of hydrogen sulphide reacting to produce 6 moles of proton. whereas the concentration of Bi2S3 is not considered as it is present in solid phase.

4 0

3 years ago

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