1 mole of an alkane gives 2 moles is correct answer
The correct answers are options C, that is, silver tarnishes and becomes black when exposed to oxygen, and option E, that is, diesel fuel burns when it is heated.
Chemical changes refer to the modifications in which the chemistry at molecular level is modified as the initial substance gets transformed into a new and different final substance. This change occurs with the dissociation of old bond and production of new bonds respectively.
Silver gets tarnished and becomes black when exposed to oxygen. This refers to a chemical change as silver a white and lustrous substance gets transformed into a tarnish black final substance. However, silver does not easily react with oxygen at usual circumstances. It easily reacts with sulfur comprising components in the air and generates black compound as Ag₂S.
Burning of diesel fuel when it is heated. Diesel refers to a mixture of hydrocarbons varying approximately from C₁₀H₂₀ to C₁₅H₂₈. When these hydrocarbons get burnt they generate novel substances, that is, carbon dioxide and water. Hence, it is also a chemical reaction.
Answer:
The molecular formula = 
Explanation:
Given that:
Mass of compound, m = 0.145 g
Temperature = 200 °C
The conversion of T( °C) to T(K) is shown below:
T(K) = T( °C) + 273.15
So,
T = (200 + 273.15) K = 473.15 K
V = 97.2 mL = 0.0972 L
Pressure = 0.74 atm
Considering,
Using ideal gas equation as:
where,
P is the pressure
V is the volume
m is the mass of the gas
M is the molar mass of the gas
T is the temperature
R is Gas constant having value = 0.0821 L.atm/K.mol
Applying the values in the above equation as:-
The empirical formula is = 
Molecular formulas is the actual number of atoms of each element in the compound while empirical formulas is the simplest or reduced ratio of the elements in the compound.
Thus,
Molecular mass = n × Empirical mass
Where, n is any positive number from 1, 2, 3...
Mass from the Empirical formula = 12 + 1 = 13 g/mol
Molar mass = 78.31 g/mol
So,
Molecular mass = n × Empirical mass
78.31 = n × 13
⇒ n ≅ 6
The molecular formula =
Answer:
975.56×10²³ molecules
Explanation:
Given data:
Number of molecules of C₂H₆ = 4.88×10²⁵
Number of molecules of CO₂ produced = ?
Solution:
Chemical equation:
2C₂H₆ + 7O₂ → 4CO₂ + 6H₂O
Number of moles of C₂H₆:
1 mole = 6.022×10²³ molecules
4.88×10²⁵ molecules×1mol/6.022×10²³ molecules
0.81×10² mol
81 mol
Now we will compare the moles of C₂H₆ with CO₂.
C₂H₆ : CO₂
2 : 4
81 : 4/2×81 = 162 mol
Number of molecules of CO₂:
1 mole = 6.022×10²³ molecules
162 mol ×6.022×10²³ molecules / 1 mol
975.56×10²³ molecules
