The rate of disappearance of HBr in the gas phase reaction 2 HBr(g) → H2(g) + Br2(g) is 0.140 M s-1 at 150°C. The rate of appear

Response:

H₂SO₄

Clarification:

Given a compound consisting of 0.475 g H, 7.557 g S, and 15.107 g O, we must compute the empirical formula by following specific steps.

Step 1: Compute the total mass of the compound

Total mass = mass H + mass S + mass O = 0.475 g + 7.557 g + 15.107 g

Total mass = 23.139 g

Step 2: Determine the percentage composition.

H: (0.475g/23.139g) × 100% = 2.05%

S: (7.557g/23.139g) × 100% = 32.66%

O: (15.107g/23.139g) × 100% = 65.29%

Step 3: Divide each percentage by the element's atomic mass

H: 2.05/1.01 = 2.03

S: 32.66/32.07 = 1.018

O: 65.29/16.00 = 4.081

Step 4: Normalize all values by the smallest one

H: 2.03/1.018 ≈ 2

S: 1.018/1.018 = 1

O: 4.081/1.018 ≈ 4

Thus, the empirical formula for the compound is H₂SO₄.

The correct equation is (C) H3O+(aq) + C2H3O2−(aq) -> HC2H3O2(aq) + H2O(l). A buffer system is composed of a weak acid and its corresponding salt, effectively stabilizing the pH levels within a solution. The buffer works by adjusting the concentrations of the conjugate acid and base, maintaining the pH constant.

Answer:

The entropy change of the surroundings is -33.5 J/K

Explanation:

The heat gained by the ice is 10 kJ, equating to 10000 J

The heat released by the surroundings is the negative of the heat gained by the ice.

Thus,

The heat lost by the surroundings = -(10000 J)

Given the room temperature = = 273 + 25 = 298 K

Thus, the entropy change of the surroundings is -33.5 J/K

Answer;

As and Sr ------- [Kr]

Be ------------- [He]

O and Mg ------- [Ne]

S and Ca ------- [Ar]

Explanation

• The Be+ ion has 2 electrons, matching He. The Mg2+ and O2− ions possess 10 electrons each, like Ne.
• S2− and Ca2+ ions each have 18 electrons, the same as Ar. The As3− and Sr+ ions hold 36 electrons, paralleling Kr.
• Elements gain or lose electrons to reach a stable electron configuration akin to that of noble gases.
• When atoms lose electrons, they form positive ions (cations), and when they gain electrons, they form negative ions (anions).

a) The completely balanced chemical reaction is:

 

Zn(s) + H2SO4(aq) --------> ZnSO4(aq) + H2 (g) 

<span>b) Initially, we determine the quantity of zinc that has reacted based on the produced H2.</span>

According to stoichiometry, 1 mole of Zn is required for each mole of H2 created, thus:

moles(Zn) = moles(H2) 

where moles are calculated as the ratio of mass to molar mass (MM)
mass(Zn) / MM(Zn) = mass(H2) / MM(H2) 
mass(Zn) = [mass(H2) / MM(H2)] * MM(Zn) 
mass(Zn) = [(0.0764 g)/(2 g/mol)] * 65.38 g/mol 
mass(Zn) = 2.49 g 

Consequently, we find 2.49 g of pure zinc in the sample, leading to a purity of zinc of: 

purity = (2.49 / 3.86) * 100 % = 64.50 % 
 

<span>c) In part (b), it is assumed that the impurities in the sample do not react with sulfuric acid to emit hydrogen. Thus, the hydrogen solely arises from the reaction of Zn with sulfuric acid.</span>