If a chemical reaction occurs in a flask, and the flask becomes colder, the reaction was exothermic. true or false

Suppose a lab group reports a ppercent yield of sand of 105. is it really possible to collect more sand than was originally represented? what is the possible explanation for the extra product?

For the reaction, 4 a(g) + 3 b(g) => 2 c(g), the following data were obtained at constant temperature. experiment initial[a],mol/l initial [b],mol/l initial rate,m/min 1 0.200 0.150 5.00 2 0.400 0.150 10.0 3 0.200 0.300 10.0 4 0.400 0.300 20.0 which of the following is the correct rate law for the reaction? 1. rate = k[a]2[b]2 2. rate = k[a][b] 3. rate = k[a]2[b] 4. rate = k[a][b]2

Apiece of metal with a length of 1.42 cm was measured using four different instruments. which of the following measurements is the most accurate?