Question

k/u - true or false
question 12 (1 point)
according to the 2nd law of thermochemistry, it is predicted that the final temperature of water would be 55 degrees, if 30 degree water and 80 degree water were mixed.
true
false
question 13 (1 point)
increasing concentration increases reaction rate by increasing collision frequency.
true
false

Explanation:

Question 12

The 2nd Law of Thermodynamics (not Thermochemistry) relates to entropy, but for mixing equal masses of 30°C and 80°C water, the final temperature (assuming equal masses, \( T_f=\frac{m_1T_1 + m_2T_2}{m_1 + m_2} \), if \( m_1 = m_2 \), \( T_f=\frac{30 + 80}{2}=55 \)) is correct. However, the law cited is misnamed (Thermochemistry vs Thermodynamics), but the temperature calculation for equal masses is 55. But the law reference is wrong, but the temperature prediction (if masses are equal) is 55. Wait, the question says "2nd Law of Thermochemistry" – there's no 2nd Law of Thermochemistry; the 2nd Law is of Thermodynamics. But the temperature calculation (for equal masses) gives 55. But the law name is incorrect. However, maybe the question assumes equal masses (implied) and the temperature calculation. But the law citation is wrong. But the temperature result (55) is correct for equal masses. But the law is mislabeled. However, the key is: if we assume equal masses, \( T_f=\frac{30 + 80}{2}=55 \). So the prediction of 55°C (for equal masses) is correct, even though the law name is miswritten (maybe a typo). So the statement's temperature prediction (given the mixing) is True (assuming equal masses, which is a common assumption if not stated otherwise).

Increasing concentration of reactants increases the number of particles per unit volume, so collision frequency (number of collisions per unit time) increases. More collisions mean a higher chance of effective collisions, so reaction rate increases. This is a fundamental concept in chemical kinetics: concentration affects reaction rate by changing collision frequency (and effective collisions). So the statement is True.

Answer:

True

Question 13