Viết các phương trình phản ứng xảy ra giữa các chất: HCOOH, CH3COOCH=CH2, CH3COOC6H5 với lần lượt các dung dịch sau: NaOH (dư), AgNO3/NH3 (dư), Br2/H2O. 2. Hoàn thành sơ đồ chuyển hoá sau:
A (C6H8O4) + NaOH X + Y + Z
X + H2SO4 E + Na2SO4
Y + H2SO4 F + Na2SO4
F R + H2O
Cho biết E, Z đều cho phản ứng tráng gương, R là axit có công thức C3H4O2

Predict the products butane (c4h10) + oxygen —>

Lab reagent, hypothesis test. a reference solution used as a lab reagent is purported to have a concentration of 5 mg/dl. six samples are taken from this solution and the following concentrations are recorded: (5.32, 4.88, 5.10, 4.73, 5.15, 4.75) mg/dl. these six measurements are assumed to be an srs of all possible measurements from solution. they are also assumed to have a standard deviation of 0.2, a normal distributin, and a mean concentration equal to the true concentration of the solution. carry out a significance test to determine whether these six measurements provide reliable evidence that the true concentration of the solution is actually not 5 mg/dl.

Which statement is true about a catalyst? a: a catalyst decreases the rate of the reaction. b. a catalyst is consumed during a chemical reaction. c. a catalyst lowers the activation energy of a reaction. d. a catalyst increases the reactant concentration during a reaction.