Answer:
Positive: a and b
Negative: c
Explanation:
The entropy (S) is the measure of the randomness of the system, and it intends to increase. The randomness can be determined by the energy of the molecules, their velocity and how distance they are between the other molecules.
When the entropy increases, ΔS is positive, when the entropy decreases, ΔS is negative. So, when gasoline mix with air in a car engine, the process intends to continue, the randomness increases and ΔS is positive. When hot air expands, the distance between the molecules increases, so ΔS is positive.
But, when humidity condenses, the molecules stay closer, so there's a decrease in the randomness, then ΔS is negative.
Answer: the answer is c.The unbalanced push causes the cart to speed up.
Explanation:
The application of an unbalanced force (the push) causes the cart to speed up. When the cart is in constant motion, the forces are balanced and there is no speeding up. Once an unbalanced force is added, the cart's speed changes.
It will dissolve fastest in a cup of hot water.
Answer:
pH =6.70
Explanation:
When Kw = 1x10^-14
[H3O+] = [OH-] --> 1x10-7
Kw =3.98x^10-14
3.98x^10-14 = [H3O+] . [OH-]
√ (3.98x^10-14) = [H3O+] = [OH-]
[H3O+] = 1.99×10^-7
- log [H3O+] = pH ---> -log 1.99x10^-7 = 6.70
