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3 years ago

When 5.175 g of lead are heated at 300 C the lead reacts with the oxygen in the air to

Chemistry

2 answers:

TEA [102]3 years ago

4 0

$2Pb+O_2=2PbO$ if the lead has valence 2 (I'm not totally certain of that, lol)

Scorpion4ik [409]3 years ago

4 0

Answer:

Mass of oxygen used is 5.708 – 5.175 g = 0.533 g Moles of lead reacting = (5.175/207) mol = 0.025 mol Moles of oxygen reacting = (0.533/32) mol = 0.0167 mol ∴0.025 mol of Pb react with 0.0167 mol of O2to give product ∴1.5 mol of Pb react with 1 mol of O2to give product ∴3 mol of Pb react with 2 mol of O2to give product 3Pb+ 2O2→Pb3O4You do not have the information to write the full equation but as you know there is only one product and this has 3 lead atoms and 4 oxygen you can suggest a formula.

Explanation:

You might be interested in

What is the molarity of a NaOH solution if 32.47 mL is required to titrate 0.6013 g of potassium hydrogen phthalate (C8H5O4K)

Artist 52 [7]

Answer:

0.0907 M

Explanation:

Before you can calculate the molarity, you need to convert grams to moles (via molar mass) and convert mL to L.

(Step 1)

Molar Mass (C₈H₅O₄K):

8(12.011 g/mol) + 5(1.008 g/mol) + 4(15.998 g/mol) + 39.098 g/mol

Molar Mass (C₈H₅O₄K): 204.218 g/mol

0.6013 g C₈H₅O₄K 1 mole
------------------------------ x ------------------ = 0.00294 moles C₈H₅O₄K
204.218 g

(Step 2)

1,000 mL = 1 L

32.47 mL 1 L
--------------- x ----------------- = 0.03247 L
1,000 mL

(Step 3)

Molarity (M) = moles / volume (L)

Molarity = 0.00294 moles / 0.03247 L

Molarity = 0.0907 M

6 0

2 years ago

Its due tomorrow answer as fast as u can

viktelen [127]

Answer:

2. Plants and animals.

5. The layers have different ages with the youngest layer on top.

6. Sedimention.

7. The presence of unconformities.

5 0

3 years ago

The pH of a 0.29 M solution of carbonic acid (H2CO3) is measured to be 3.44. Calculate the acid dissociation constant Ka of carb

arsen [322]

Answer: 4.55x10^-7

Explanation:

H2CO3 + H20 <==> H3O+ + HCO3-

Desigining an ICE table, we have:

Initial conc. of H2CO3 = 0.29 M

Initial conc. of H3O+ = 0

Initial conc. of HCO3- = 0

Change in conc. of H2CO3 = - x

Change in conc. of H3O+ = x

Change in conc. of HCO3- = x

Equilibrium conc. of H2CO3 = 0.29 - x

Equilibrium conc. of H3O+ = x

Equilibrium conc. of HCO3- = x

but pH = 3.44

pH = - log[H30+]

[H30+] = 10^-3.44 = 3.63x10^-4

[H30+] = 3.63x10^-4

Ka = [H3O+].[HCO3-] / [H2CO3]

[H30+] = x = 3.63x10^-4

[HCO3-] = 3.63x10^-4

[H2CO3] = 0.29 - x = 0.29 - 3.63x10^-4 = 0.289637

Ka = (3.63x10^-4)(3.63x10^-4)/0.289637 = 4.55x10^-7

6 0

3 years ago

A compound has an M-/M-2 ratio of 75:25. Which of the following could be the molecular formula of this compound? a) CH2Br2 b) CH

Lera25 [3.4K]

Answer:

c) CH₃Cl

Explanation:

Due the relative abundance of chlorine and bromine. It is possible to determine which of the halogens is present in a mass spectrum of a organic compound:

The Cl-35, Cl-37 have a relative abundance of 75/25; Br-79 and Br-81 of 50/50.

For that reason, if a compound has a M/M+2 ratio of 75:25 you can be sure the compound has 1 Cl in its structure. Thus, the only possible structure is:

3 0

3 years ago

A certain reaction has an activation energy of 51.64 kj/mol. At what temperature Kelvin will the reaction be 5.50 times faster t

pishuonlain [190]

For this, we use the Arrhenius equation to solve the problem. It is expressed as:
k = Ae^-(E/RT)

where k is the reaction rate, A is the pre-exponential factor, E is the activation energy and T is the temperature.

For a reaction, A is constant at different temperatures. We then isolate the constant and then introduce the second condition to the equation since it will still be equal to the constant. It is then simplified to:

ln(k2/k1) = -E/R (1/T2 - 1/T1)
ln(5.50k1/k1) = -51.64/8.314 (1/T2 - 1/343)
T2 = 379 K

3 0

3 years ago