Answer: The molar mass of the unknown compound is 200 g/mol
Explanation:
Depression in freezing point is given by:
= Depression in freezing point
i= vant hoff factor = 1 (for molecular compound)
= freezing point constant = 
m= molality
Weight of solvent (benzene)= 0.250 kg
Molar mass of solute = M g/mol
Mass of solute = 26.7 g
Thus the molar mass of the unknown compound is 200 g/mol
Answer:
The reaction is spontaneous when T > 2170 K.
Explanation:
The spontaneity of a reaction is related to the standard Gibbs free energy (ΔG°). When ΔG° < 0 the reaction is spontaneous. ΔG° is related to the standard enthalpy (ΔH°) and the standard entropy (ΔS°) through the following expression:
ΔG° = ΔH° - T.ΔS°
where,
T is the absolute temperature
The reaction is spontaneous when ΔG° < 0, that is,
ΔH° - T.ΔS° < 0
ΔH° < T.ΔS°
T > ΔH°/ΔS° = (169.4 × 10³ J)/(78.1 J/K) = 2170 K
The reaction is spontaneous when T > 2170 K.
Answer:
Moles of water in 7.1×10²⁵ molecules are 118 mol.
Explanation:
Given data:
Number of molecules of water = 7.1×10²⁵ molecules
Moles of water in 7.1×10²⁵ molecules = ?
Solution;
The given problem will solve by using Avogadro number.
It is the number of atoms , ions and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance.
The number 6.022 × 10²³ is called Avogadro number.
For example,
1 mole = 6.022 × 10²³ molecules of water
7.1×10²⁵ molecules of water × 1 mol / 6.022 × 10²³ molecules of water
1.18×10² moles of water 0r 118 moles of water
Answer:
113.4g of N2
Explanation:
Step 1:
The balanced equation for the reaction.
N2 + 3H2 —> 2NH3
Step 2:
Determination of the mass of N2 and H2 that reacted from the balanced equation. This is illustrated below:
Molar mass of N2 = 2x14 = 28g/mol
Mass of N2 from the balanced equation = 1 x 28 = 28g
Molar mass of H2 = 2x1 = 2g/mol
Mass of H2 from the balanced equation = 3 x 2 = 6g
From the balanced equation above, 28g of N2 reacted with 6g of H2.
Step 3:
Determination of the mass N2 required to react with 24.3g of H2.
The mass of N2 required to react with 24.3g of H2 can be obtained as follow:
From the balanced equation above, 28g of N2 reacted with 6g of H2.
Therefore, Xg of N2 will react 24.3g of H2 i.e
Xg of N2 = (28 x 24.3)/6
Xg of N2 = 113.4g
Therefore, 113.4g of N2 is required to react completely with 24.3g of H2.
