Answer: D. An increase in entropy
Explanation:
Entropy is the measure of randomness or disorder of a system. If a system moves from an disordered arrangement to an ordered arrangement, the entropy is said to increase and vice versa.
For a reaction to be spontaneous, the enthalpy of the solution must decrease and the entropy must increase.
To overcome a positive enthalpy of solution and allow a solid solute to dissolve in water, an increase in entropy would make the reaction spontaneous as the system would move to a more disordered state.
Answer:

Explanation:
1. Calculate the rate constant
The integrated rate law for first order decay is

where
A₀ and A_t are the amounts at t = 0 and t
k is the rate constant

2. Calculate the half-life

Answer:
Length = 393pm, Density = 21.3 g/cm^3.
Explanation:
From the question above, we have the following parameters or data which is going to aid in solving the above Question.
=> The radius of a platinum atom = 139 pm.
Therefore, the length can be calculated by making use of the formula given below:
Length = 2 √( 2r) = 2 × √ (2 × 139 × 10^-12m ) = 393 × 10^-10 m = 393pm.
The density can be calculated by making use of the chemical formula given below:
Density = mass ÷ volume = (195.064/ 6.02 × 10^23) ÷ (3.93 × 10^-10/ 10^-2) = 21.3 g/cm^3.
Answer:
H
Explanation:
This will give it the perfect balance to roll straight and steady.