The answer for the question is c.
Explanation:
Given problem:
Find the molar mass of:
SO₃ and C₁₀H₈
Solution:
The molar mass of a compound is the mass in grams of one mole of the substance.
To solve this, we are going to add the individual atomic masses of the elements in the compound;
Atomic mass;
S = 32g/mol; O = 16g/mol; C = 12g/mol and H = 1g/mol
For SO₃;
= 32 + 3(16)
= 32 + 48
= 80g/mol
For C₁₀H₈
= 10(12) + 8(1)
= 120 + 8
= 128g/mol
Answer: 94.13 L
Explanation: In STP in an ideal gas there is a standard value for both temperature and pressure. At STP,pressure is equal to 1atm and the temperature at 0°C is equal to 273.15K. This problem is an ideal gas so we use PV=nRT where R is a constant R= 0.08205 L.atm/mol.K.
To find volume, derive the equation, it becomes V=nRT/P. Substitute the values. V= 4.20 mol( 0.08205L.atm/mol.K)(273.15K) / 1 atm = 94.13 L. The mole units, atm and K will be cancelled out and L will be the remaining unit which is for volume.
<u>Given:</u>
Change in internal energy = ΔU = -5084.1 kJ
Change in enthalpy = ΔH = -5074.3 kJ
<u>To determine:</u>
The work done, W
<u>Explanation:</u>
Based on the first law of thermodynamics,
ΔH = ΔU + PΔV
the work done by a gas is given as:
W = -PΔV
Therefore:
ΔH = ΔU - W
W = ΔU-ΔH = -5084.1 -(-5074.3) = -9.8 kJ
Ans: Work done is -9.8 kJ
