Answer: A central nervous system stimulant
Explanation: arguably the most frequently ingested pharmacologically active substance in the world.
Answer: The correct option would be A.
Explanation: The main group elements which make more bonds than that was predicted from the octet rule are supposed to have expanded octet.
These elements tend to have more than 8 valence electrons after bonding and this can be achieved when we have empty d-orbitals.
When we have empty p-orbitals, total number of valence electrons than can be occupied will be 8.
Electronic configuration when valence shell's empty p-orbitals are fully filled = 
which means that a total of 8 electrons can be occupied which does not satisfy expanded octet rule.
Example of molecule showing expanded octet rule is given in the image. Here, after bonding Phosphorous has 10 electrons which is occupied in empty d-orbitals.
Answer:
2C4H10 + 13O2 ----> 4CO2 + 10H2O
The coefficient of oxygen in the balanced equation is 13
Answer:
The rate of the reaction increased by a factor of 1012.32
Explanation:
Applying Arrhenius equation
ln(k₂/k₁) = Ea/R(1/T₁ - 1/T₂)
where;
k₂/k₁ is the ratio of the rates which is the factor
Ea is the activation energy = 274 kJ/mol.
T₁ is the initial temperature = 231⁰C = 504 k
T₂ is the final temperature = 293⁰C = 566 k
R is gas constant = 8.314 J/Kmol
Substituting this values into the equation above;
ln(k₂/k₁) = 274000/8.314(1/504 - 1/566)
ln(k₂/k₁) = 32956.4589 (0.00198-0.00177)
ln(k₂/k₁) = 6.92
k₂/k₁ = exp(6.92)
k₂/k₁ = 1012.32
The rate of the reaction increased by 1012.32